- Omega-3 fatty acid
Types of fats in food See also
N−3 fatty acids (popularly referred to as ω−3 fatty acids or omega-3 fatty acids) are essential unsaturated fatty acids with a double bond (C=C) starting after the third carbon atom from the end of the carbon chain.
The carbon chain has two ends—the acid (COOH) end and the methyl (CH3) end. The location of the first double bond is counted from the methyl end, which is also known as the omega (ω) end or the n end.
Common sources of n–3 fatty acids include fish oils and some plant oils such as flaxseed oil and algal oil. Mammalian brains are also an extremely rich source of not only n-3 fatty acids in general, but DHA in particular. However, eating animal brains, which continue to be considered a delicacy in other parts of the world, has become virtually culturally obsolete in the modern West, to the point that most widely available sources do not even bother to list brains as a potential source. There are potential adverse consequences to eating brains of animals who may be carriers of particular kinds of disease.
Mammals cannot synthesize n−3 fatty acids, but have a limited ability to form the "long-chain" n−3 fatty acids EPA (20-carbon atoms) and DHA (22-carbon atoms) from the "short-chain" eighteen-carbon n−3 fatty acid ALA.
N−3 fatty acids that are important in human physiology are α-linolenic acid (18:3, n−3; ALA), eicosapentaenoic acid (20:5, n−3; EPA), and docosahexaenoic acid (22:6, n−3; DHA). These three polyunsaturates have either 3, 5, or 6 double bonds in a carbon chain of 18, 20, or 22 carbon atoms, respectively. As with most naturally-produced fatty acids, all double bonds are in the cis-configuration; in other words, the two hydrogen atoms are on the same side of the double bond.
List of n−3 fatty acids
This table lists several different names for the most common n−3 fatty acids found in nature.
Common name Lipid name Chemical name Hexadecatrienoic acid (HTA) 16:3 (n−3) all-cis-7,10,13-hexadecatrienoic acid α-Linolenic acid (ALA) 18:3 (n−3) all-cis-9,12,15-octadecatrienoic acid Stearidonic acid (SDA) 18:4 (n−3) all-cis-6,9,12,15-octadecatetraenoic acid Eicosatrienoic acid (ETE) 20:3 (n−3) all-cis-11,14,17-eicosatrienoic acid Eicosatetraenoic acid (ETA) 20:4 (n−3) all-cis-8,11,14,17-eicosatetraenoic acid Eicosapentaenoic acid (EPA) 20:5 (n−3) all-cis-5,8,11,14,17-eicosapentaenoic acid Heneicosapentaenoic acid (HPA) 21:5 (n−3) all-cis-6,9,12,15,18-heneicosapentaenoic acid Docosapentaenoic acid (DPA),
22:5 (n−3) all-cis-7,10,13,16,19-docosapentaenoic acid Docosahexaenoic acid (DHA) 22:6 (n−3) all-cis-4,7,10,13,16,19-docosahexaenoic acid Tetracosapentaenoic acid 24:5 (n−3) all-cis-9,12,15,18,21-tetracosapentaenoic acid Tetracosahexaenoic acid (Nisinic acid) 24:6 (n−3) all-cis-6,9,12,15,18,21-tetracosahexaenoic acid
Significance to human nutrition and health
Although omega-3 fatty acids have been known as essential to normal growth and health since the 1930s, awareness of their health benefits has dramatically increased since the 1990s. New versions of ethyl esterized omega-3 fatty acids, such as E-EPA and combinations of E-EPA and E-DHA, have drawn attention as highly purified and more effective products than the traditional ones. In the United States and European Union, these novel versions are often sold as prescription medications, such as Lovaza. Elsewhere they are available as dietary supplements.
The health benefits of the long-chain omega-3 fatty acids — DHA and EPA omega-3 — are the best-known. These benefits were discovered in the 1970s by researchers studying the Greenland Inuit Tribe. The Greenland Inuit people consumed large amounts of fat from meat, but displayed virtually no cardiovascular disease. The high level of omega-3 fatty acids consumed by the Inuit reduced triglycerides, heart rate, blood pressure, and atherosclerosis.
On September 8, 2004, the U.S. Food and Drug Administration gave "qualified health claim" status to EPA and DHA n−3 fatty acids, stating that "supportive but not conclusive research shows that consumption of EPA and DHA [n−3] fatty acids may reduce the risk of coronary heart disease." This updated and modified their health risk advice letter of 2001 (see below). As of this writing, regulatory agencies[who?] do not accept that there is sufficient evidence for any of the suggested benefits of DHA and EPA other than for cardiovascular health, and further claims should be treated with caution.
The Canadian Government has recognized the importance of DHA omega-3 and permits the following biological role claim for DHA: "DHA, an omega-3 fatty acid, supports the normal development of the brain, eyes and nerves."
- The biological effects of the n−3 are largely mediated by their interactions with the n−6 fatty acids; see Essential fatty acid interactions for detail.
The 'essential' fatty acids were given their name when researchers found that they are essential to normal growth in young children and animals. (Note that the modern definition of 'essential' is more strict.) A small amount of n−3 in the diet (~1% of total calories) enabled normal growth, and increasing the amount had little to no additional effect on growth.
Likewise, researchers found that n−6 fatty acids (such as γ-linolenic acid and arachidonic acid) play a similar role in normal growth. However, they also found that n−6 was "better" at supporting dermal integrity, renal function, and parturition. These preliminary findings led researchers to concentrate their studies on n−6, and it is only in recent decades that n−3 has become of interest.
In 1964, it was discovered that enzymes found in sheep tissues convert n−6 arachidonic acid into the inflammatory agent called prostaglandin E2, which both causes the sensation of pain and expedites healing and immune response in traumatized and infected tissues. By 1979, more of what are now known as eicosanoids were discovered: thromboxanes, prostacyclins, and the leukotrienes. The eicosanoids, which have important biological functions, typically have a short active lifetime in the body, starting with synthesis from fatty acids and ending with metabolism by enzymes. However, if the rate of synthesis exceeds the rate of metabolism, the excess eicosanoids may have deleterious effects. Researchers found that certain n−3 fatty acids are also converted into eicosanoids, but at a much slower rate. Eicosanoids made from n−3 fatty acids are often referred to as anti-inflammatory, but in fact they are just less inflammatory than those made from n−6 fats. If both n−3 and n−6 fatty acids are present, they will "compete" to be transformed, so the ratio of long-chain n−3:n−6 fatty acids directly affects the type of eicosanoids that are produced.
This competition was recognized as important when it was found that thromboxane is a factor in the clumping of platelets, which can both cause death by thrombosis and cause death by bleeding. Likewise, the leukotrienes were found to be important in immune/inflammatory-system response, and therefore relevant to arthritis, lupus, asthma, and recovery from infections. These discoveries led to greater interest in finding ways to control the synthesis of n−6 eicosanoids. The simplest way would be by consuming more n−3 and fewer n−6 fatty acids.
When administered as the ethyl ester, the omega-3 fatty acid EPA appears to form potent anti-inflammatory molecules, called resolvins and omega-3-oxylipins, which may partly explain the positive effects of fish oil.
The n-3 fatty acids DHA and EPA may act as direct ligands to the GPR 120 receptor, a recently discovered type of GPCR(G-protein coupled receptor), affecting anti-inflammatory and insulin sensitization in mice.
Conversion efficiency of ALA to EPA and DHA
The short-chain n−3 fatty acids are converted to long-chain forms (EPA, DHA) with an efficiency below 5% in men, and at a greater percentage in women which may be due to the importance for meeting the demands of the fetus and neonate for DHA.
These conversions occur competitively with n−6 fatty acids, which are essential closely related chemical analogues that are derived from linoleic acid. Both the n−3 α-linolenic acid and n−6 linoleic acid must be obtained from food. Synthesis of the longer n−3 fatty acids from linolenic acid within the body is competitively slowed by the n−6 analogues. Thus, accumulation of long-chain n−3 fatty acids in tissues is more effective when they are obtained directly from food or when competing amounts of n−6 analogs do not greatly exceed the amounts of n−3.
The conversion of ALA to EPA and further to DHA in humans has been reported to be limited, but varies with individuals. Women have higher ALA conversion efficiency than men, it is presumed due to the lower rate of use of dietary ALA for beta-oxidation. This suggests that biological engineering of ALA conversion efficiency is possible. Goyens et al. argue that it is the absolute amount of ALA, rather than the ratio of n−3 and n−6 fatty acids, that controls the conversion efficiency.
The n−6 to n−3 ratio
Some clinical studies indicate that the ingested ratio of n−6 to n−3 (especially linoleic vs alpha-linolenic) fatty acids is important to maintaining cardiovascular health. However, two studies published in 2005 and 2007 found that while n−3 polyunsaturated fatty acids are extremely beneficial in preventing heart disease in humans, the levels of n−6 polyunsaturated fatty acids (and therefore the ratios) were insignificant.
Both n−3 and n−6 fatty acids are essential; i.e., humans must consume them in the diets. N−3 and n−6 eighteen-carbon polyunsaturated fatty acids compete for the same metabolic enzymes, thus the n−6:n−3 ratio will significantly influence the ratio of the ensuing eicosanoids (hormones), (e.g., prostaglandins, leukotrienes, thromboxanes, etc.), and will alter the body's metabolic function. In general, grass-fed animals accumulate more n−3 than do grain-fed animals, which accumulate relatively more n−6. Metabolites of n−6 are more inflammatory (esp. arachidonic acid) than those of n−3. This necessitates that n−3 and n−6 be consumed in a balanced proportion; healthy ratios of n−6:n−3 range from 1:1 to 1:4 (an individual needs more n−3 than n−6.) Studies suggest the evolutionary human diet, rich in game animals, seafood, and other sources of n−3, may have provided such a ratio.
Typical Western diets provide ratios of between 10:1 and 30:1 (i.e., dramatically higher levels of n−6 than n-3). The ratios of n−6 to n−3 fatty acids in some common vegetable oils are: canola 2:1, soybean 7:1, olive 3–13:1, sunflower (no n−3), flax 1:3, cottonseed (almost no n−3), peanut (no n−3), grapeseed oil (almost no n−3) and corn oil 46:1 ratio of n−6 to n−3.
As a Harvard expert explains, n-6 fatty acids also reduce inflammation and protect against heart disease, so the n-3 to n-6 ratio "is of no value in evaluating diet quality or predicting disease".
Potential health benefits
The 18 carbon α-linolenic acid (ALA) has not been shown to have the same cardiovascular benefits that DHA or EPA may have. Currently, there are many products on the market that claim to contain health-promoting "omega 3", but contain only ALA, not EPA or DHA. These products contain mainly plant oils and must be converted by the body to create DHA. DHA and EPA are made by marine microalgae. These are then consumed by fish and accumulate to high levels in their internal organs. The United States Environmental Protection Agency issues fish consumption advisories to empower Americans to avoid toxic mercury levels in certain fish and shellfish while still reaping the possible health benefits of consuming fish and shellfish.
Some evidence suggests that people with certain circulatory problems, such as varicose veins, may benefit from the consumption of EPA and DHA, which may stimulate blood circulation, increase the breakdown of fibrin, a compound involved in clot and scar formation, and, in addition, may reduce blood pressure. Evidently, n−3 fatty acids reduce blood triglyceride levels, and regular intake may reduce the risk of secondary and primary heart attack. A systematic review of studies prior to 2005 showed that ALA does not confer the cardiovascular health benefits of EPA and DHA.
There is preliminary evidence that EPA supplementation, either with DPA or medication, is helpful in cases of depression There is also limited evidence that supplementation with n-3 fatty acids, alone or in combination with n-6 fatty acids, may reduce anxiety, however, the only live study to suggest an anxiety reducing effect involved α-Linolenic acid (as opposed to EPA or DPA). The New York Times, however, reports that at least one study has not found a connection between depression in heart patients taking Sertraline and daily supplements containing two grams total of EPA and DHA during a ten-week period.
Some research suggests that fish oil intake may reduce the risk of ischemic and thrombotic stroke, although large amounts may actually increase the risk of hemorrhagic stroke (see below): Lower amounts are not related to this risk; 3 grams of total EPA/DHA daily are generally recognized as safe (GRAS) with no increased risk of bleeding involved and many studies used substantially higher doses without major side effects (for example: 4.4 grams EPA/2.2 grams DHA in 2003 study).
Several studies report possible anti-cancer effects of n−3 fatty acids (in particular, breast, colon, and prostate cancer). Omega-3 fatty acids reduced prostate tumor growth, slowed histopathological progression, and increased survival in mice. Among n-3 fatty acids, neither long-chain nor short-chain forms were consistently associated with breast cancer risk. High levels of DHA, however, the most abundant n-3 PUFA in erythrocyte membranes, were associated with a reduced risk of breast cancer. Conversely, a 2011 study, the largest ever done involving 3,400 men, examined the association of dietary fats and prostate cancer risk, and found that men with the highest blood percentages of DHA have two-and-a-half-times the risk of developing aggressive, high-grade prostate cancer compared to men with the lowest DHA levels.
A 2006 report in the Journal of the American Medical Association, in their review of literature covering cohorts from many countries with a wide variety of demographics, concluded that there was no link between n−3 fatty acids and cancer. This is similar to the findings of a review by the British Medical Journal of studies up to February 2002 that failed to find clear effects of long and shorter chain n−3 fats on total mortality, combined cardiovascular events and cancer.
A 2007 systematic review of n-3 fatty acids and cachexia found evidence that oral n-3 fatty acid supplements benefit cancer patients, improving appetite, weight, and quality of life. A 2009 trial found that a supplement of eicosapentaenoic acid helped cancer patients retain muscle mass.
In 1999, the GISSI-Prevenzione Investigators reported in The Lancet the results of major clinical study in 11,324 patients with a recent myocardial infarction. Treatment 1 gram per day of n−3 fatty acids reduced the occurrence of death, cardiovascular death, and sudden cardiac death by 20%, 30%, and 45%, respectively. These beneficial effects were seen from three months onwards.
In April 2006, a team led by Lee Hooper at the University of East Anglia in Norwich, UK, published a review of almost 100 separate studies of n−3 fatty acids found in abundance in oily fish. It concluded that they do not have a significant protective effect against cardiovascular disease. This meta-analysis was controversial and stands in stark contrast with two different reviews also performed in 2006 by the American Journal of Clinical Nutrition and a second JAMA review; both indicated decreases in total mortality and cardiovascular incidents (i.e., myocardial infarctions) associated with the regular consumption of fish and fish oil supplements.
In the March 2007 edition of the journal Atherosclerosis, 81 Japanese men with unhealthy blood sugar levels were randomly assigned to receive 1800 mg daily of eicosapentaenoic acid (EPA), with the other half being a control group. The thickness of the carotid arteries and certain measures of blood flow were measured before and after supplementation. This went on for approximately two years. A total of 60 patients (30 in the E-EPA group and 30 in the control group) completed the study. Those given the EPA had a statistically significant decrease in the thickness of the carotid arteries, along with improvement in blood flow. The authors indicated that this was the first demonstration that administration of purified EPA improved the thickness of carotid arteries and improved blood flow in patients with unhealthy blood sugar levels.
In a study published in the American Journal of Health-System Pharmacy March 2007, patients with high triglycerides and poor coronary artery health were given 4 grams a day of a combination of EPA and DHA along with some monounsaturated fatty acids. Those patients with very unhealthy triglyceride levels (above 500 mg/dl) reduced their triglycerides on average 45% and their VLDL cholesterol by more than 50%. VLDL is a "bad" type of cholesterol, and elevated triglycerides can also be deleterious for cardiovascular health.
A study on the benefits of EPA published in The Lancet in March 2007 involved over 18,000 patients with unhealthy cholesterol levels. The patients were randomly assigned to receive either 1,800 mg a day of E-EPA with a statin drug or a statin drug alone. The trial lasted five years. At the end of the study, those patients in the E-EPA group had superior cardiovascular function and nonfatal coronary events were also significantly reduced. The authors concluded that EPA is a promising treatment for prevention of major coronary events, especially nonfatal coronary events.
Similar to those following a Mediterranean diet, Arctic-dwelling Inuit - who consume high amounts of n−3 fatty acids from fatty fish - also tend to have higher proportions of n−3, increased HDL cholesterol and decreased triglycerides (fatty material that circulates in the blood), and less heart disease. Eating walnuts (the ratio of n−6 to n−3 is circa 4:1) was reported to lower total cholesterol by 4% relative to controls when people also ate 27% less cholesterol.
A study of 465 women showed that serum levels of EPA are inversely related to levels of anti-oxidized-LDL antibodies. Oxidative modification of LDL is thought to play an important role in the development of atherosclerosis.
Survivors of past myocardial infarctions are less likely to die from an arrhythmic event if they are consuming high levels of n-3. These antiarrhythmic effects are thought to be due to n-3 fatty acids' ability to increase the fibrillation threshold of the heart tissue.
N-3 fatty acids also have mild antihypertensive effects. When subjects consumed n-3 from oily fish on a regular basis, their systolic blood pressure was lowered by about 3.5-5.5 mmHg.
In a study regarding fish oil published in the Journal of Nutrition in April 2007, sixty-four healthy Danish infants from nine to twelve months of age received either cow's milk or infant formula alone or with fish oil. Those infants supplemented with fish oil were found to have improvement in immune function maturation, with no apparent reduction in immune activation.
Limited evidence suggests that long-chain n-3 fatty acids may delay or prevent the progression of certain psychotic disorders in high-risk children and adolescents. The individuals diagnosed with schizophrenia exhibited reduced levels of both n-6 and n-3 polyunsaturated fatty acids, and the results of a study in which the treatment of high-risk children with a dietary supplement containing both eicosapentaenoate and docosahexaenoate produced a statistically significant (95% confidence, but not 97.5% confidence) decrease in progression to schizophrenia.
Consumption of ethyl eicosapentaenoate (E-EPA) partially countered memory impairment in a rat model of Alzheimer's disease and produced a statistically insignificant decrease in human depression.
Studies looking at the effects of omega-3 fatty acids on cognitive performance have seen mixed results. A study published in 2005 showed beneficial effects of omega-3 fatty acids in the cognitive performance of health subjects. However, a later study found that fish oil had no effect on cognitive performance in individuals 65 years of age or older without dementia.
Although not confirmed as an approved health claim, current research suggests that the anti-inflammatory activity of long-chain n−3 fatty acids may translate into clinical effects. For example, there is evidence that rheumatoid arthritis sufferers taking long-chain n−3 fatty acids from sources such as fish have reduced pain compared to those receiving standard NSAIDs.
Noncardiac health risks
In a letter published October 31, 2000, the United States Food and Drug Administration Center for Food Safety and Applied Nutrition, Office of Nutritional Products, Labeling, and Dietary Supplements noted that known or suspected risks of EPA and DHA consumed in excess of 3 grams per day may include the possibility of:
- Increased incidence of bleeding
- Hemorrhagic stroke
- Oxidation of omega-3 fatty acids, forming biologically active oxidation products
- Increased levels of low-density lipoproteins (LDL) cholesterol or apoproteins associated with LDL cholesterol among diabetics and hyperlipidemics
- Reduced glycemic control among diabetics
Subsequent advice from the FDA and national counterparts have permitted health claims associated with heart health.
Persons with congestive heart failure, chronic recurrent angina pectoris, or evidence that their heart is receiving insufficient blood flow are advised to talk to their doctors before taking n−3 fatty acids.
In a recent large study, n−3 fatty acids on top of standard heart failure therapy produced a small but statistically significant benefit in terms of mortality and hospitalization. In congestive heart failure, cells that only barely receive enough blood flow become electrically hyperexcitable. This can lead to increased risk of irregular heartbeats, which, in turn, can cause sudden cardiac death. Certain n−3 fatty acids seem to stabilize the rhythm of the heart by effectively preventing these hyperexcitable cells from functioning, thereby reducing the likelihood of sudden cardiac death. For most people, this is beneficial and could account for most of the large reduction in the likelihood of sudden cardiac death. Nevertheless, for people with congestive heart failure, the heart is barely pumping blood well enough to keep them alive. In these patients, n−3 fatty acids may eliminate enough of these few pumping cells that the heart would no longer be able to pump sufficient blood to live, causing an increased, rather than decreased, risk of cardiac death.
Although not supported by current scientific evidence as a primary treatment for ADHD, autism spectrum disorders, and other developmental differences, omega-3 fatty acids have gained popularity for children with these conditions. A 2004 Internet survey found that 29% of surveyed parents used essential fatty acid supplements to treat children with autistic spectrum disorders.
Omega-3 fatty acids offer a promising complementary approach to standard treatments for ADHD and developmental coordination disorder. Fish oils appear to reduce ADHD-related symptoms in some children. Double blind studies have shown "medium to strong treatment effects of omega 3 fatty acids on symptoms of ADHD" after administering amounts around 1 gram for three to six months.
A 2009 survey concluded that there is not enough scientific evidence to support the effectiveness of 'n-3 fatty acids for autism spectrum disorders. One randomized controlled trial found that n-3 fatty acids did not significantly affect aberrant behavior in autistic children, and although the investigators noted reduced hyperactivity, their later reanalysis reported that the reduction was not statistically significant.
Low birth weight
In a study of nearly 9,000 pregnant women, researchers found that women that ate fish once a week during their first trimester had 27% less risk of low birth weight and premature birth than those that ate no fish. Low consumption of fish was a strong risk factor for preterm delivery and low birth weight, but attempts by other groups to reverse this increased risk by encouraging increased prenatal consumption of fish were unsuccessful.
n−3 fatty acids are thought by some to have membrane-enhancing capabilities in brain cells. One medical explanation is that n−3 fatty acids play a role in the fortification of the myelin sheaths. It is no coincidence that n−3 fatty acids comprise approximately eight percent of the average human brain, according to Dr. David Horrobin, a pioneer in fatty acid research. Ralph Holman of the University of Minnesota, another major researcher studying essential fatty acids, who gave omega-3 its name, surmised how n−3 components are analogous to the human brain by stating that "DHA is structure; EPA is function."
A benefit of n−3 fatty acids is helping the brain to repair damage by promoting neuronal growth. In a six-month study involving people with schizophrenia and Huntington's disease who were treated with E-EPA or a placebo, the placebo group had clearly lost cerebral tissue, while the patients given the supplements had a significant increase of grey and white matter.
In the prefrontal cortex (PFC) of the brain, low brain n−3 fatty acids are thought to lower the dopaminergic neurotransmission, possibly contributing to the negative and neurocognitive symptoms in schizophrenia. This reduction in dopamine system function in the PFC may lead to an overactivity in dopaminergic function in the limbic system of the brain, which is suppressively controlled by the PFC dopamine system, causing the positive symptoms of schizophrenia. This is called the n−3 polyunsaturated fatty acid/dopamine hypothesis of schizophrenia (Ohara, 2007). This mechanism may explain why n−3 supplementation shows effects against both positive, negative and cognitive symptoms in schizophrenia.
As a consequence, the past decade of n−3 fatty acid research has procured some Western interest in n−3 fatty acids as being a legitimate 'brain food.' Still, recent claims that one's intelligence quotient, psychological tests measuring certain cognitive skills, including numerical and verbal reasoning skills, are increased on account of n−3 fatty acids consumed by pregnant mothers remain unreliable and controversial. An even more significant focus of research, however, lies in the role of n−3 fatty acids as a non-prescription treatment for certain psychiatric and mental diagnoses and has become a topic of much research and speculation. A 2011 report of preliminary research on mice found that omega-3 deficiency is linked to depression and mood disorders.
In 1998, Andrew L. Stoll, MD and his colleagues at Harvard University conducted a small double-blind placebo-controlled study in thirty patients diagnosed with bipolar disorder. Most subjects in this study were already undergoing psychopharmacological treatment (e.g., 12 out of the 30 were taking lithium). Over the course of four months, he gave 15 subjects capsules containing olive oil, and another 15 subjects capsules containing nine grams of pharmaceutical-quality EPA and DHA. The study showed that subjects in the n−3 group were less likely to experience a relapse of symptoms in the four months of the study. Moreover, the n−3 group experienced significantly more recovery than the placebo group. However, a commentary on the Stoll study notes that the improvement in the n−3 group was too small to be clinically significant. Though Stoll believes that the 1999 experiment was not as optimal as it could have been and has accordingly pursued further research, the foundation has been laid for more researchers to explore the theoretical association between absorbed n−3 fatty acids and signal transduction inhibition in the brain.
"Several epidemiological studies suggest covariation between seafood consumption and rates of mood disorders. Biological marker studies indicate deficits in omega−3 fatty acids in people with depressive disorders, while several treatment studies indicate therapeutic benefits from omega-3 supplementation. A similar contribution of omega-3 fatty acids to coronary artery disease may explain the well-described links between coronary artery disease and depression. Deficits in omega-3 fatty acids have been identified as a contributing factor to mood disorders and offer a potential rational treatment approach." In 2004, a study found that 100 suicide attempt patients on average had significantly lower levels of EPA in their blood as compared to controls.
In a recent study, low levels of DHA were associated with an increased risk of suicide for members of the U.S. military.
In 2006, the Omega-3 Fatty Acids Subcommittee, assembled by the Committee on Research on Psychiatric Treatments of the American Psychiatric Association (APA) stated the following: "The preponderance of epidemiologic and tissue compositional studies supports a protective effect of omega-3 EFA intake, particularly eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), in mood disorders. Meta-analyses of randomized controlled trials demonstrate a statistically significant benefit in unipolar and bipolar depression (p=.02). The results were highly heterogeneous, indicating that it is important to examine the characteristics of each individual study to note the differences in design and execution. There is less evidence of benefit in schizophrenia. EPA and DHA appear to have negligible risks and some potential benefit in major depressive disorder and bipolar disorder, but results remain inconclusive in most areas of interest in psychiatry. Health benefits of omega-3 EFA may be especially important in patients with psychiatric disorders, due to high prevalence rates of smoking and obesity and the metabolic side effects of some psychotropic medications."  
Another meta-analysis published in the Journal of Clinical Psychiatry in 2007, based on 10 clinical trials, found that Omega-3 polyunsaturated fatty acids significantly improved depression in patients with both unipolar and bipolar disorder. However, based upon the heterogeneity of the trials, the authors concluded that "more large-scale, well-controlled trials are needed to find out the favorable target subjects, therapeutic dose of EPA and the composition of omega-3 PUFAs in treating depression". A small American trial, published in 2009, concluded that E-EPA, as monotherapy, demonstrated a statistically insignificant advantage over placebo, thought to be due to study limitations. However, a 2011 longitudinal study of over 50,000 women, conducted at Harvard University, found no association between intake of EPA and DPA and a reduction in depression, over a period of ten years. The study did, on the other hand, find that intake of α-Linolenic acid was positively associated with a significant reduction in depression in the same group.
As macronutrients, fats are not assigned recommended daily allowances. Macronutrients have acceptable intake (AI) levels and acceptable macronutrient distribution ranges (AMDRs) instead of RDAs. The AI for n−3 is 1.6 grams/day for men and 1.1 grams/day for women,, while the AMDR is 0.6% to 1.2% of total energy.
A growing body of literature suggests that higher intakes of α-linolenic acid (ALA), eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) may afford some degree of protection against coronary heart disease. Because the physiological potency of EPA and DHA is much greater than that of ALA, it is not possible to estimate one AMDR for all n−3 fatty acids. Approximately 10 percent of the AMDR can be consumed as EPA and/or DHA." There was insufficient evidence as of 2005 to set an upper tolerable limit for n−3 fatty acids.
Heavy metal poisoning by the body's accumulation of traces of heavy metals, in particular mercury, lead, nickel, arsenic, and cadmium, is a possible risk from consuming fish oil supplements. Also, other contaminants (PCBs, furans, dioxins, and PBDEs) might be found, especially in less-refined fish oil supplements. In reality, however, heavy metal toxicity from consuming fish oil supplements is highly unlikely, because heavy metals selectively bind with protein in the fish flesh rather than accumulate in the oil. An independent test in 2006 of 44 fish oils on the US market found all of the products passed safety standards for potential contaminants. The FDA recommends that the total dietary intake of n−3 fatty acids from fish not exceed 3 grams per day, with no more than 2 grams per day from nutritional supplements.
Throughout their history, the Council for Responsible Nutrition and the World Health Organization have published acceptable standards regarding contaminants in fish oil. The most stringent current standard is the International Fish Oils Standard. Fish oils that are molecularly distilled under vacuum typically make this highest-grade, and have measurable levels of contaminants (measured parts per billion and parts per trillion).
A recent trend has been to fortify food with n−3 fatty acid supplements. Global food companies have launched n−3 fatty acid fortified bread, mayonnaise, pizza, yogurt, orange juice, children's pasta, milk, eggs, popcorn, confections, and infant formula.
The American Heart Association has set up dietary recommendations for EPA and DHA due to their cardiovascular benefits: Individuals with no history of coronary heart disease or myocardial infarction should consume oily fish or fish oils two times per week; those having been diagnosed with coronary heart disease after infarction should consume 1 g EPA and DHA per day from oily fish or supplements; those wishing to lower blood triglycerides should consume 2-4 g of EPA and DHA per day in the form of supplements.
The most widely available dietary source of EPA and DHA is cold water oily fish, such as salmon, herring, mackerel, anchovies, and sardines. Oils from these fish have a profile of around seven times as much n−3 as n−6. Other oily fish, such as tuna, also contain n−3 in somewhat lesser amounts. Consumers of oily fish should be aware of the potential presence of heavy metals and fat-soluble pollutants like PCBs and dioxins, which are known to accumulate up the food chain. After extensive review, researchers from Harvard's School of Public Health in the Journal of the American Medical Association (2006) reported that the benefits of fish intake generally far outweigh the potential risks. Although fish is a dietary source of n−3 fatty acids, fish do not synthesize them; they obtain them from the algae (microalgae in particular) or plankton in their diets.
Grams of n−3 per 3oz (85g) serving  Common name grams n−3 Herring, sardines 1.3–2 Spanish mackerel, Atlantic, Pacific 1.1–1.7 Salmon 1.1–1.9 Halibut 0.60–1.12 Tuna 0.21–1.1 Swordfish 0.97 Greenshell/lipped mussels 0.95 Tilefish 0.9 Tuna (canned, light) 0.17–0.24 Pollock 0.45 Cod 0.15–0.24 Catfish 0.22–0.3 Flounder 0.48 Grouper 0.23 Mahi mahi 0.13 Orange roughy 0.028 Red snapper 0.29 Shark 0.83 King mackerel 0.36 Hoki (blue grenadier) 0.41 Gemfish 0.4 Blue eye cod 0.31 Sydney rock oysters 0.3 Tuna, canned 0.23 Snapper 0.22 Eggs, large regular 0.109 Barramundi, saltwater 0.1 Giant tiger prawn 0.1 Lean red meat 0.031 Turkey 0.03 Cereals, rice, pasta, etc. 0 Fruit 0 Milk regular 0 Regular bread 0 Vegetables 0 Vegetable oils and spreads 0
As fish oil supplements are bought for their healthful n-3 fatty acid content, it is therefore vital for manufacturers and suppliers of these products to ensure they do not contain high levels of dioxins and other toxins.
Not all forms of fish oil may be equally digestible. Of four studies that compare bioavailability of the glyceryl ester form of fish oil vs. the ethyl ester form, two have concluded the natural glyceryl ester form is better, and the other two studies did not find a significant difference. No studies have shown the ethyl ester form to be superior, although it is cheaper to manufacture.
Krill oil is a newly discovered source of n−3 fatty acids. Various claims are made in support of krill oil as a superior source of n−3 fatty acids. The effect of krill oil, at a lower dose of EPA + DHA (62.8%), was demonstrated to be similar to that of fish oil.
Green-lipped mussels from New Zealand (Perna canaliculus) are another source of n-3 fatty acids. The book The Inflammation Revolution by George Halpern, MD., PhD., professor at Hong Kong Polytechnic University discusses the effects of green-lipped mussels in comparison to NSAIDs in the treatment of inflammatory conditions, in particular arthritis. Lyprinol is a patented New Zealand mussel oil extract.
These tables are incomplete.
Common name Alternative name Linnaean name % ALA Perilla shiso Perilla frutescens 61 Chia seed chia sage Salvia hispanica 58 Flax linseed Linum usitatissimum 55 Lingonberry Cowberry Vaccinium vitis-idaea 49 Camelina Gold-of-pleasure Camelina sativa 36 Purslane Portulaca Portulaca oleracea 35 Black raspberry Rubus occidentalis 33 Hemp Cannabis sativa 19 Common name Linnaean name % ALA Flaxseed Linum usitatissimum 18.1 Butternuts Juglans cinerea 8.7 Hempseed Cannabis sativa 8.7 Persian walnuts Juglans regia 6.3 Pecan nuts Carya illinoinensis 0.6 Hazel nuts Corylus avellana 0.1
Flaxseed (or linseed) (Linum usitatissimum) and its oil are perhaps the most widely available botanical source of the n−3 fatty acid ALA. Flaxseed oil consists of approximately 55% ALA, which makes it six times richer than most fish oils in n−3 fatty acids, although it contains negligible amounts of EPA and DHA, the n-3 fatty acids that FDA considers healthful."
Purslane contains more ALA than any other leafy vegetable plant. Purslane also contains .01 mg/g (0.001%) of EPA, which is an extraordinary amount for a vegetable source.
Eggs produced by hens fed a diet of greens and insects contain higher levels of n−3 fatty acids than chickens fed corn or soybeans. In addition to feeding chickens insects and greens, fish oils may be added to their diets to increase the n-3 fatty acid concentrations in eggs.
The addition of flax and canola seeds to the diets of chickens, both good sources of alpha-linolenic acid, increases the omega-3 content of the eggs, predominantly DHA. 
The addition of green algae or seaweed to the diets boosts the content of DHA and EPA content, which are the forms of omega-3 approved by the FDA for medical claims. A common consumer complaint is "Omega-3 eggs can sometimes have a fishy taste if the hens are fed marine oils."
Omega 3 fatty acids are formed in the chloroplasts of green leaves and algae. While seaweeds and algae are the source of omega 3 fatty acids present in fish, grass is the source of omega 3 fatty acids present in grass fed meats. When cattle are taken off omega 3 fatty acid rich grass and shipped to a feedlot to be fattened on omega 3 fatty acid deficient grain, they begin losing their store of this beneficial fat. Each day that an animal spends in the feedlot, the amount of omega 3 fatty acids in its meat is diminished.
In a 2009 study which was a joint effort between the USDA and researchers at Clemson University in South Carolina grass-fed beef was compared with grain-fed beef and researchers found that grass-fed beef is: lower in total fat, higher in beta-carotene, higher in vitamin E (alpha-tocopherol), higher in the B-vitamins thiamin and riboflavin, higher in the minerals calcium, magnesium, and potassium, higher in total omega-3s, higher in CLA (cis-9 trans-11) which is a potential cancer fighter, higher in vaccenic acid (which can be transformed into CLA), lower in the saturated fats linked with heart disease, and has a healthier ratio of omega-6 to omega-3 fatty acids (1.65 vs 4.84).
In most countries, commercially available lamb is typically grass-fed, and thus higher in n−3 than other grain-fed or grain-finished meat sources. In the United States, lamb is often finished (i.e., fattened before slaughter) with grain, resulting in lower n−3.
Mammalian brains and eyes
The brains and eyes of mammals are extremely rich in DHA as well as other n-3 fatty acids. DHA is a major structural component of the mammalian brain, and is in fact the most abundant (n-3) fatty acid in the brain. According to SelfNutritionData, a mere 3 oz. of pan-fried lamb brain provides over 3800 mg of n-3 fatty acids, and only 168 mg of n-6. Further, it contains 1033 mg of DHA, making it by far the richest non-seafood source of DHA.
Although eating brains has widely fallen out of custom in the United States, it was fairly common in the Southern United States in the recent past, and it is still sometimes possible to find canned pork brains in southern supermarkets. According to NutritionData, a 3 oz. serving of pork brains contains 680 mg of DHA.
Seal oil is a source of EPA, DPH, and DPA. According to Health Canada, it helps to support the development of the brain, eyes and nerves in children up to 12 years of age. However, like all seal products, it is not allowed for import into the European Union
The microalgae Crypthecodinium cohnii and Schizochytrium are rich sources of DHA, but not EPA, and can be produced commercially in bioreactors. This is the only source of DHA acceptable to vegans.
In 2006 a study was published in the Journal of Dairy Science entitled "The Linear Relationship between the Proportion of Fresh Grass in the Cow Diet, Milk Fatty Acid Composition, and Butter Properties". It was found that grass fed butter contains substantially more CLA, vitamin E, beta-carotene, and omega-3 fatty acids than butter from cows raised in factory farms or that have limited access to pasture. It was also found that the softer the butter, the more fresh pasture in the cow’s diet. Cows that get all their nutrients from grass have the softest butterfat of all.
Notes and references
- ^ Venturi S; Bégin ME (2010). "Thyroid Hormone, Iodine and Human Brain Evolution". In Cunnane S; Stewart K. Environmental Influences on Human Brain Evolution. John Wiley & Sons. pp. 105–124. ISBN 978-0-470-45268-4.
- ^ Cocchi, M.; Venturi, S. (2000). "Iodide, antioxidant function and Omega-6 and Omega-3 fatty acids: a new hypothesis of a biochemical cooperation?". Progress in Nutrition 2: 15–19.
- ^ Ingenbleek, Y; Jung, L; Férard, G; Bordet, F; Goncalves, AM; Dechoux, L (1997). "Iodised rapeseed oil for eradication of severe endemic goitre". Lancet 350 (9090): 1542–5. doi:10.1016/S0140-6736(97)02427-6. PMID 9388412.
- ^ Ingenbleek Y, Jung L, Férard G (2000). "Brassiodol: A new iodised oil for eradication of endemic goitre". Journal of Trace Elements in Medicine and Biology 13 (1): 85–96. doi:10.1002/(SICI)1520-670X(2000)13:1<85::AID-JTRA10>3.0.CO;2-E.
- ^ Holman RT (February 1998). "The slow discovery of the importance of omega 3 essential fatty acids in human health". J. Nutr. 128 (2 Suppl): 427S–433S. PMID 9478042.
- ^ Dyerberg J, Bang HO, Hjorne N (1975). "Fatty acid composition of the plasma lipids in Greenland Eskimos". Am J Clin Nutr 28 (9): 958–66. PMID 1163480.
- ^ a b "FDA announces qualified health claims for omega-3 fatty acids" (Press release). United States Food and Drug Administration. September 8, 2004. http://www.fda.gov/SiteIndex/ucm108351.htm. Retrieved 2006-07-10.
- ^ Canadian Food Inspection Agency. Summary Table of Biological Role Claims Table 8-2. http://www.inspection.gc.ca/english/fssa/labeti/guide/ch8e.shtml
- ^ a b c d e f Lands, William E.M. (1 May 1992). "Biochemistry and physiology of n–3 fatty acids". FASEB Journal (Federation of American Societies for Experimental Biology) 6 (8): 2530–2536. PMID 1592205. http://www.fasebj.org/content/6/8/2530.full.pdf. Retrieved 2008-03-21.
- ^ Bergstrom, Danielson, Klenberg, and Samuelsson (Nov 1964). "The Enzymatic Conversion of Essential fatty Acids into Prostaglandins". The Journal of Biological Chemistry 239 (11): PC4006–PC4008. http://www.jbc.org/content/239/11/PC4006.full.pdf.
- ^ Shearer GC, Harris WS, Pedersen TL, Newman JW. (August 2009) Detection of omega-3 oxylipins in human plasma and response to treatment with omega-3 acid ethyl esters. J Lipid Res. Full Free text
- ^ Da Young Oh, Saswata Talukdar, Eun Ju Bae, Takeshi Imamura, Hidetaka Morinaga, WuQiang Fan, Pingping Li, Wendell J. Lu, Steven M. Watkins, Jerrold M. Olefsky. (September 2010) GPR120 Is an Omega-3 Fatty Acid Receptor Mediating Potent Anti-inflammatory and Insulin-Sensitizing Effects. Cell, Volume 142, Issue 5, 687-698, 3 September 2010. 
- ^ Gerster H (1998). "Can adults adequately convert alpha-linolenic acid (18:3n-3) to eicosapentaenoic acid (20:5n-3) and docosahexaenoic acid (22:6n-3)?". Int. J. Vitam. Nutr. Res. 68 (3): 159–173. PMID 9637947.
- ^ Brenna JT (March 2002). "Efficiency of conversion of alpha-linolenic acid to long chain n-3 fatty acids in man.". Curr. Opin. Clin. Nutr. Metab. Care 5 (2): 127–132. doi:10.1097/00075197-200203000-00002. PMID 11844977.
- ^ Burdge GC, Calder PC (September 2005). "Conversion of alpha-linolenic acid to longer-chain polyunsaturated fatty acids in human adults.". Reprod. Nutr. Dev. 45 (5): 581–597. doi:10.1051/rnd:2005047. PMID 16188209.
- ^ "Conversion Efficiency of ALA to DHA in Humans". http://dhaomega3.org/index.php?category=overview&title=Conversion-of-ALA-to-DHA. Retrieved 21 October 2007.
- ^ Goyens, Petra LL et al. (1 July 2006). "Conversion of alpha-linolenic acid in humans is influenced by the absolute amounts of alpha-linolenic acid and linoleic acid in the diet and not by their ratio". American Journal of Clinical Nutrition 84 (1): 44–53. PMID 16825680. http://www.ajcn.org/cgi/content/abstract/84/1/44. Retrieved 21 October 2007.
- ^ Okuyama H (2001). "High n−6 to n−3 ratio of dietary fatty acids rather than serum cholesterol as a major risk factor for coronary heart disease". Eur J Lipid Sci Technol 103 (6): 418–422. doi:10.1002/1438-9312(200106)103:6<418::AID-EJLT418>3.0.CO;2-#.
- ^ Griffin BA (2008). "How relevant is the ratio of dietary n−6 to n−3 polyunsaturated fatty acids to cardiovascular disease risk? Evidence from the OPTILIP study". Curr. Opin. Lipidol. 19 (1): 57–62. doi:10.1097/MOL.0b013e3282f2e2a8. PMID 18196988.
- ^ Mozaffarian D, Ascherio A, Hu FB, Stampfer MJ, Willett WC, Siscovick DS, Rimm EB., D; Ascherio, A; Hu, FB; Stampfer, MJ; Willett, WC; Siscovick, DS; Rimm, EB (2005). "Interplay Between Different Polyunsaturated Fatty Acids and Risk of Coronary Heart Disease in Men". Circulation 111 (2): 157–64. doi:10.1161/01.CIR.0000152099.87287.83. PMC 1201401. PMID 15630029. http://circ.ahajournals.org/cgi/content/full/111/2/157.
- ^ Willett WC, WC (2007). "The role of dietary n-6 fatty acids in the prevention of cardiovascular disease". J Cardiovasc Med 8: Suppl 1:S42–5. doi:10.2459/01.JCM.0000289275.72556.13. PMID 17876199.
- ^ Tribole, E.F.; Thompson, RL; Harrison, RA; Summerbell, CD; Ness, AR; Moore, HJ; Worthington, HV; Durrington, PN et al. (2006). "Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review". BMJ 332 (7544): 752–760. doi:10.1136/bmj.38755.366331.2F. PMC 1420708. PMID 16565093. http://www.bmj.com/cgi/eletters/332/7544/752#130637. Retrieved 2008-03-23.
- ^ a b c S.K. Duckett et al, Journal of Animal Science, (published online) June 2009, “Effects of winter stocker growth rate and finishing system on: III. Tissue proximate, fatty acid, vitamin and cholesterol content.”
- ^ Tribole, 2007
- ^ Lands, 2005
- ^ Simopoulos, AP (September 2003). "Importance of the ratio of omega-6/omega-3 essential fatty acids: evolutionary aspects". World Review of Nutrition and Dietetics. World Review of Nutrition and Dietetics 92: 1–174. doi:10.1159/000073788. ISBN 3-8055-7640-4. PMID 14579680.
- ^ Simopoulos AP, Leaf A, Salem Jr N (2000). "Workshop Statement on the essentiality of and recommended dietary intakes for n−6 and n−3 fatty acids". Prostaglandins Leukot Essent Fatty Acids 63 (3): 119–121. doi:10.1054/plef.2000.0176. PMID 10991764.
- ^ Hibbeln et al., 2006
- ^ Erasmus, Udo, Fats and Oils. 1986. Alive books, Vancouver, ISBN 0-920470-16-5 p. 263 (round-number ratio within ranges given.)
- ^ "Essential Fats in Food Oils, NIH page". http://efaeducation.nih.gov/sig/esstable.html.
- ^ "Ask the Expert: Omega-3 Fatty Acids". Harvard University. 21 April 2009. http://www.hsph.harvard.edu/nutritionsource/questions/omega-3/index.html. Retrieved 6 April 2011. ""Omega-6 fatty acids lower LDL cholesterol (the "bad" cholesterol) and reduce inflammation, and they are protective against heart disease. So both omega-6 and omega-3 fatty acids are healthy. While there is a theory that omega-3 fatty acids are better for our health than omega-6 fatty acids, this is not supported by the latest evidence. Thus, the omega-3 to omega-6 ratio is basically the "good divided by the good," so it is of no value in evaluating diet quality or predicting disease.""
- ^ von Schacky C. (March 2003). "The role of omega-3 fatty acids in cardiovascular disease". Curr. Atheroscler. Rep. 5 (2): 139–45. doi:10.1007/s11883-003-0086-y. PMID 12573200.
- ^ name="EPA" ,
- ^ Morris, Martha C.; Sacks, Frank; Rosner, Bernard (1993). "Does fish oil lower blood pressure? A meta-analysis of controlled trials". Circulation 88 (2): 523–533. PMID 8339414. http://circ.ahajournals.org/cgi/reprint/88/2/523/.
- ^ Mori, Trevor A.; Bao, Danny Q.; Burke, Valerie; Puddey, Ian B.; Beilin, Lawrence J. (1993). "Docosahexaenoic acid but not eicosapentaenoic acid lowers ambulatory blood pressure and heart rate in humans". Hypertension 34 (2): 253–260. PMID 10454450. http://hyper.ahajournals.org/cgi/reprint/34/2/253/.
- ^ Harris, William S. (1997). "n−3 fatty acids and serum lipoproteins: human studies". Am J Clin Nutr 65 (5 Sup.): 1645S–1654S. PMID 9129504. http://www.ajcn.org/cgi/reprint/65/5/1645S/.
- ^ Sanders, T.A.B.; Oakley, F.R.; Miller, G.J.; Mitropoulos, K.A.; Crook, D.; Oliver, M.F. (1997). "Influence of n−6 versus n−3 polyunsaturated fatty acids in diets low in saturated fatty acids on plasma lipoproteins and hemostatic factors". Arteriosclerosis, Thrombosis, and Vascular Biology 17 (12): 3449–3460. doi:10.1161/01.ATV.17.12.3449. PMID 9437192. http://atvb.ahajournals.org/cgi/content/full/17/12/3449.
- ^ Roche, H.M.; Gibney, M.J. (1996). "Postprandial triacylglycerolaemia: the effect of low-fat dietary treatment with and without fish oil supplementation". Eur J Clin Nutr. 50 (9): 617–624. PMID 8880041. http://cat.inist.fr/?aModele=afficheN&cpsidt=3232572.
- ^ Davidson MH, Stein EA, Bays HE, Maki KC, Doyle RT, Shalwitz RA, Ballantyne CM, Ginsberg HN (2007). "Efficacy and tolerability of adding prescription omega-3 fatty acids 4 g/d to Simvastatin 40 mg/d in hypertriglyceridemic patients: An 8-week, randomized, double-blind, placebo-controlled study". Clin Ther. 29 (7): 1354–1367. doi:10.1016/j.clinthera.2007.07.018. PMID 17825687.
- ^ Bucher HC, Hengstler P, Schindler C, Meier G. (2002). "n−3 polyunsaturated fatty acids in coronary heart disease: a meta-analysis of randomized controlled trials". Am J Med 112 (4): 298–304. doi:10.1016/S0002-9343(01)01114-7. PMID 11893369.
- ^ Burr, Michael L.; Sweetham, P.M.; Fehily, Ann M. (August 1994). "Diet and reinfarction". European Heart Journal 15 (8): 1152–1153. PMID 7988613. http://eurheartj.oxfordjournals.org/cgi/reprint/15/8/1152.
- ^ Willett, Walter C.; Stampfer, M.J.; Colditz, G.A.; Speizer, F.E.; Rosner, B.A.; Hennekens, C.H. (1993). "Intake of trans fatty acids and risk of coronary heart disease among women". The Lancet 341 (8845): 581–585. doi:10.1016/0140-6736(93)90350-P. PMID 8094827.
- ^ Stone, Neil J. (1996). "Fish consumption, fish oil, lipids, and coronary heart disease". Circulation 94 (9): 2337–2340. PMID 8901708. http://circ.ahajournals.org/cgi/content/full/94/9/2337.
- ^ Wang, C.; Harris, W. S.; Chung, M.; Lichtenstein, A. H.; Balk, E. M.; Kupelnick, B.; Jordan, H. S.; Lau, J. (2006). "N-3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review". The American journal of clinical nutrition 84 (1): 5–17. PMID 16825676.
- ^ Fortin PR, Lew RA, Liang MH, Wright EA, Beckett LA, Chalmers TC, Sperling RI. (1995). "Validation of a meta-analysis: The effects of fish oil in rheumatoid arthritis". J Clin Epidemiol 48 (11): 1379–1390. doi:10.1016/0895-4356(95)00028-3. PMID 7490601.
- ^ Kremer, Joel M.; Bigauoette, J.; Michalek, A.V.; Timchalk, M.A.; Lininger, L.; Rynes, R.I.; Huyck, C.; Zieminski, J.; Bartholomew, L.E. (1985). "Effects of manipulation of dietary fatty acids on clinical manifestations of rheumatoid arthritis". The Lancet (Elsevier) 1 (8422): 184–187. doi:10.1016/S0140-6736(85)92024-0. PMID 2857265.
- ^ Christensen, Jeppe H.; Gustenhoff, Peter; Ejlersen, Ejler; Jessen, Torben; Korup, Eva; Rasmussen, Klaus; Dyerberg, Jørn; Schmidt, Erik B. (January 1995). "n−3 fatty acids and ventricular extrasystoles in patients with ventricular tachyarrhythmias". Nutrition Research 15 (1): 1–8. doi:10.1016/0271-5317(95)91647-U.
- ^ Christensen, Jeppe H.; Gustenhoff, Peter; Korup, Eva; Aarøe, Jens; Toft, Egon; Møller, Torn; Rasmussen, Klaus; Dyerberg, Jørn; Schmidt, Erik B. (1996-03-16). "Effect of fish oil on heart rate variability in survivors of myocardial infarction: a double blind randomised controlled trial". BMJ 312 (7032): 677–678. PMC 2350515. PMID 8597736. http://www.bmj.com/cgi/content/full/312/7032/677.
- ^ Pignier, C.; Revenaz, C.; Rauly-Lestienne, I.; Cussac, D.; Delhon, A.; Gardette, J.; Le Grand, B. (2007). "Direct protective effects of poly-unsaturated fatty acids, DHA and EPA, against activation of cardiac late sodium current". Basic Research in Cardiology (Steinkopff Verlag) 102 (6): 553–564. doi:10.1007/s00395-007-0676-x. PMID 17891522. http://www.springerlink.com/content/u454873774830225/.
- ^ a b Su, Kuan-Pin; Huang, Shih-Yi; Chiub, Chih-Chiang; Shenc, Winston W. (2003). "Omega-3 fatty acids in major depressive disorder: A preliminary double-blind, placebo-controlled trial". Eur Neuropsychopharmacol 13 (4): 267–271. doi:10.1016/S0924-977X(03)00032-4. PMID 12888186.
- ^ Naliwaiko, K.; Araújo, R.L.; da Fonseca, R.V.; Castilho, J.C.; Andreatini, R.; Bellissimo, M.I.; Oliveira, B.H.; Martins, E.F.; Curi, R.; Fernandes, L.C.; Ferraz, A.C. (April 2004). "Effects of fish oil on the central nervous system: a new potential antidepressant?". Nutritional Neuroscience (Maney) 7 (2): 91–99. doi:10.1080/10284150410001704525. PMID 15279495.
- ^ Nemets, Boris; Stahl, Ziva; Belmaker, R.H. (2002). "Addition of omega-3 fatty acid to maintenance medication treatment for recurrent unipolar depressive disorder". Am J Psychiatry 159 (3): 477–479. doi:10.1176/appi.ajp.159.3.477. PMID 11870016.
- ^ Green, Pnina; Hermesh, Haggai; Monselisec, Assaf; Maromb, Sofi; Presburgerb, Gadi; Weizman, Abraham (2006). "Red cell membrane omega-3 fatty acids are decreased in nondepressed patients with social anxiety disorder". Eur Neuropsychopharmacol 16 (2): 107–113. doi:10.1016/j.euroneuro.2005.07.005. PMID 16243493.
- ^ Yehuda S., Rabinovitz S., Mostofsky D.I. (2005). "Mixture of essential fatty acids lowers test anxiety". Nutritional Neuroscience 8 (4): 265–267. doi:10.1080/10284150500445795. PMID 16491653.
- ^ Caryn Rabin, Roni (October 26, 2009). "Regimens: Omega-3 Fats Fail to Lift Depression in Heart Patients". The New York Times. http://www.nytimes.com/2009/10/27/health/research/27regimens.html.
- ^ Carney, Robert; Freedland, Kenneth; Rubin, Eugene; Rich, Michael; Steinmeyer, Brian; Harris, William (2009). "Omega-3 Augmentation of Sertraline in Treatment of Depression in Patients with Coronary Heart Disease". JAMA 302 (15): 1651–1657. doi:10.1001/jama.2009.1487. PMID 19843899. http://jama/ama-assn.org/cgi/content/full/302/15/1651
- ^ Keli, S.O.; Feskens, E.J.; Kromhout, D. (1994). "Fish consumption and risk of stroke: The Zutphen Study". Stroke 25 (2): 328–332. doi:10.1161/01.STR.25.2.328. PMID 8303739.
- ^ Gillum, R.F.; Mussolino, M.E.; Madans, J.H. (1996). "The relationship between fish consumption and stroke incidence: The NHANES I Epidemiologic Follow-up Study (National Health and Nutrition Examination Survey)". Arch Intern Med 156 (5): 537–542. doi:10.1001/archinte.156.5.537. PMID 8604960.
- ^ a b Iso, H.; Rexrode, K.M.; Stampfer, M.J.; Manson, J.E.; Colditz, G.A.; Speizer, F.E.; Hennekens, C.H.; Willett, W.C. (2001). "Intake of fish and omega-3 fatty acids and risk of stroke in women". JAMA 285 (3): 304–312. doi:10.1001/jama.285.3.304. PMID 11176840.
- ^ The U.S. Food and Drug Administration classification - GRAS (Generally Recognized as Safe)
- ^ Augustsson, Katarina et al. (2003). "A prospective study of intake of fish and marine fatty acids and prostate cancer". Cancer Epidemiology, Biomarkers & Prevention 12 (1): 64–67. PMID 12540506.
- ^ De Deckere, E.A. (1999). "Possible beneficial effect of fish and fish n−3 polyunsaturated fatty acids in breast and colorectal cancer". Eur J Cancer Prev 8 (3): 213–221. doi:10.1097/00008469-199906000-00009. PMID 10443950.
- ^ Caygill, C.P.; Hill, M.J. (1995). "Fish, n−3 fatty acids and human colorectal and breast cancer mortality". Eur J Cancer Prev 4 (4): 329–332. doi:10.1097/00008469-199508000-00008. PMID 7549825.
- ^ Yong Q. Chen et al. (2007). "Modulation of prostate cancer genetic risk by omega-3 and omega-6 fatty acids". J Clin Invest 117 (7): 1866–75. doi:10.1172/JCI31494. PMC 1890998. PMID 17607361. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1890998.
- ^ Pala V et al. (2001). "Erythrocyte Membrane Fatty Acids and Subsequent Breast Cancer: a Prospective Italian Study". JNCL 93 (14): 1088–95. doi:10.1093/jnci/93.14.1088. PMID 11459870. http://jnci.oxfordjournals.org/cgi/content/full/93/14/1088. Retrieved 2008-11-30.
- ^ Brasky T et al. (2011). "Serum Phospholipid Fatty Acids and Prostate Cancer Risk: Results From the Prostate Cancer Prevention Trial". Am. J. Epidemiol. 173 (12): 1429–39. doi:10.1093/aje/kwr027. PMC 3145396. PMID 21518693. http://aje.oxfordjournals.org/content/early/2011/04/19/aje.kwr027.full.pdf+html. Retrieved 2011-04-24.
- ^ Fred Hutchinson Cancer Research Center (2011-04-25). "High percentage of omega-3s in the blood may boost risk of aggressive prostate cancer". eurekalert.org. http://www.eurekalert.org/pub_releases/2011-04/fhcr-hpo042511.php. Retrieved 2011-08-10.
- ^ MacLean, Catherine H. et al. (2006). "Effects of n−3 Fatty Acids on Cancer Risk". JAMA 295 (4): 403–415. doi:10.1001/jama.295.4.403. PMID 16434631. http://jama.ama-assn.org/cgi/content/short/295/4/403. Retrieved 2006-07-07.
- ^ Lee Hooper et al. (2006). "Risks and benefits of omega 3 fats for mortality, cardiovascular disease, and cancer: systematic review". BMJ 332 (7544): 752–760. doi:10.1136/bmj.38755.366331.2F. PMC 1420708. PMID 16565093. http://bmj.bmjjournals.com/cgi/reprint_abr/332/7544/752/. Retrieved 2006-07-07.
- ^ Colomer R, Moreno-Nogueira JM, García-Luna PP et al. (May 2007). "N-3 fatty acids, cancer and cachexia: a systematic review of the literature". Br. J. Nutr. 97 (5): 823–31. doi:10.1017/S000711450765795X. PMID 17408522.
- ^ Ryan AM, Reynolds JV, Healy L et al. (2009). "Enteral nutrition enriched with eicosapentaenoic acid (EPA) preserves lean body mass following esophageal cancer surgery: results of a double-blinded randomized controlled trial". Ann. Surg. 249 (3): 355–63. doi:10.1097/SLA.0b013e31819a4789. PMID 19247018.
- ^ <Please add first missing authors to populate metadata.> (1999). "Dietary supplementation with n−3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial". Lancet 354 (9177): 447–455. doi:10.1016/S0140-6736(99)07072-5. PMID 10465168.
- ^ Marchioli R.; Barzi, F; Bomba, E; Chieffo, C; Di Gregorio, D; Di Mascio, R; Franzosi, MG; Geraci, E et al. (2002). "Early protection against sudden death by n-3 polyunsaturated fatty acids after myocardial infarction: time-course analysis of the results of the GISSI-Prevenzione". Circulation 105 (16): 1897–1903. doi:10.1161/01.CIR.0000014682.14181.F2. PMID 11997274.
- ^ a b Trivedi, Bijal (2006-09-23). "The good, the fad, and the unhealthy". New Scientist: pp. 42–49. http://www.newscientist.com/channel/health/mg19125701.300-the-good-the-fad-and-the-unhealthy.html.
- ^ Wang, C; Harris WS, Chung M, Lichtenstein AH, Balk EM, Kupelnick B, Jordan HS, Lau J (July 2006). "n−3 Fatty acids from fish or fish-oil supplements, but not alpha-linolenic acid, benefit cardiovascular disease outcomes in primary- and secondary-prevention studies: a systematic review". Am J Clin Nutr 84 (1): 5–17. PMID 16825676.
- ^ Mozaffarian, Dariush; Rimm, Eric B. (October 2006). "Fish intake, contaminants, and human health: evaluating the risks and the benefits". JAMA 296 (15): 1885–1899. doi:10.1001/jama.296.15.1885. PMID 17047219.
- ^ Mita, T; Watada H, Ogihara T, Nomiyama T, Ogawa O, Kinoshita J, Shimizu T, Hirose T, Tanaka Y, Kawamori R (2007). "Eicosapentaenoic acid reduces the progression of carotid intima-media thickness in patients with type 2 diabetes". Atherosclerosis 191 (1): 162–167. doi:10.1016/j.atherosclerosis.2006.03.005. PMID 16616147.
- ^ McKenney, James M.; Sica, Domenic (2007). "Prescription omega-3 fatty acids for the treatment of hypertriglyceridemia". Am J Health-Sys Pharm 64 (6): 595–605. doi:10.2146/ajhp060164. PMID 17353568.
- ^ Yokoyama, M; Origasa H, Matsuzaki M, Matsuzawa Y, Saito Y, Ishikawa Y, Oikawa S, Sasaki J, Hishida H, Itakura H, Kita T, Kitabatake A, Nakaya N, Sakata T, Shimada K, Shirato K (March 2007). "Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomised open-label, blinded endpoint analysis". Lancet 369 (9567): 1090–1098. doi:10.1016/S0140-6736(07)60527-3. PMID 17398308.
- ^ "Nutrition Facts and Analysis for Nuts, Walnuts, English". NutritionData. http://www.nutritiondata.com/facts-C00001-01c20oc.html.
- ^ Zambón, D.; Sabaté, J.; Muñoz, S.; Campero, B.; Casals, E.; Merlos, M.; Laguna, J.C.; Ros, E. (2000). "Substituting walnuts for monounsaturated fat improves the serum lipid profile of hypercholesterolemic men and women: A randomized crossover trial". Annals of Internal Medicine 132 (7): 538–546. PMID 10744590.
- ^ Garrido-Sánchez, L.; García-Fuentes, E.; Rojo-Martínez, G.; Cardona, F.; Soriguer, F.; Tinahones, F.J. (February 2008). "Inverse relation between levels of anti-oxidized-LDL antibodies and eicosapentanoic acid (EPA)". Br J Nut 22 (3): 1–5. doi:10.1017/S0007114508921723. PMID 18252023.
- ^ Christiansen J, Gustenhoff P, Korup E, Aaroe J, Toft E, Moller T, & Schmidt, EB (1996). "Effect of fish oil on heart rate variability in survivors of myocardial infarction: a double blind randomised controlled trial". British Medical Journal 312 (7032): 677–8. PMC 2350515. PMID 8597736. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2350515.
- ^ Murnaghan MF (1981). "Effects of fatty acids on the ventricular arrhythmia threshold in the isolated heart of the rabbit". British Journal of Pharmacology: 909–915.
- ^ Appel LF, Miller ER, Sidler AJ, Whelton PK (1993). "Does supplementation of diet with 'fish oil' reduce blood pressure? A meta-analysis of controlled clinical trials". Archives of Internal Medicine 153 (12): 1429–1438. doi:10.1001/archinte.153.12.1429. PMID 8141868.
- ^ Damsgaard, Camilla T.; Lauritzen, Lotte; Kjær, Tanja M.R.; Holm, Puk M.I.; Fruekilde, Maj-Britt; Michaelsen, Kim F.; Frøkiær, Hanne (2007). "Fish oil supplementation modulates immune function in healthy infants". J Nutr 137 (4): 1031–1036. PMID 17374672. http://jn.nutrition.org/cgi/reprint/137/4/1031.
- ^ Amminger GP, Schäfer M, Papageorgiou K, et al. "Long-Chain omega-3 Fatty Acids for Indicated Prevention of Psychotic Disorders: A Randomized, Placebo-Controlled Trial." Arch Gen Psychiatry. 2010;67(2):146-154. Full Free Text
- ^ Taepavarapruk P, Song C. (Dec 2009) "Reductions of acetylcholine release and nerve growth factor expression are correlated with memory impairment induced by interleukin-1beta administrations: effects of omega-3 fatty acid EPA treatment." J Neurochem. 
- ^ Mischoulon D, Papakostas GI, Dording CM, et al. (Dec 2009) "A double-blind, randomized controlled trial of ethyl-eicosapentaenoate for major depressive disorder." Journal of Clinical Psychiatry. 
- ^ Fontani, G.; Corradeschi, F.; Felici, A.; Alfatti, F.; Migliorini, S.; Lodi, L. (2005). "Cognitive and physiological effects of Omega-3 polyunsaturated fatty acid supplementation in healthy subjects". European Journal of Clinical Investigation 35 (11): 691–699. doi:10.1111/j.1365-2362.2005.01570.x. PMID 16269019.
- ^ van de Rest, O.; Geleijnse, J. M.; Kok, F.J.; van Staveren, W.A.; Dullemeijer, C.; OldeRikkert, M.G.M.; Beekman, A. T.F.; de Groot, C. P.G.M. (August 2008). "Effect of fish oil on cognitive performance in older subjects". Neurology 71 (6): 430–438. doi:10.1212/01.wnl.0000324268.45138.86. PMID 18678826.
- ^ Wall R, Ross RP, Fitzgerald GF, Stanton C (2010). "Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids". Nutr Rev 68 (5): 280–9. doi:10.1111/j.1753-4887.2010.00287.x. PMID 20500789.
- ^ Ruggiero C, Lattanzio F, Lauretani F, Gasperini B, Andres-Lacueva C, Cherubini A (2009). "Fatty acids from fish: the anti-inflammatory potential of long-chain omega-3 fatty acids". Curr Pharm Des 15 (36): 4135–48. PMID 20041815.
- ^ Lewis, Christine J.. "Letter Regarding Dietary Supplement Health Claim for Omega-3 Fatty Acids and Coronary Heart Disease". http://www.fda.gov/ohrms/dockets/dockets/95s0316/95s-0316-Rpt0272-38-Appendix-D-Reference-F-FDA-vol205.pdf. and "Letter Regarding Dietary Supplement Health Claim for Omega-3 Fatty Acids and Coronary Heart Disease". U.S. Food and Drug Administration via Internet Archive. October 31, 2000. Archived from the original on 2006-12-17. http://web.archive.org/web/20061217002249/http://vm.cfsan.fda.gov/~dms/ds-ltr11.html. Retrieved 2009-10-30.
- ^ a b Ornish, Dean (2006-05-02). "The Dark Side of Good Fats". Newsweek: p. 2. Archived from the original on 2008-05-22. http://web.archive.org/web/20080522084931/http://www.newsweek.com/id/137192. Retrieved 2008-06-14.
- ^ Gissi-Hf Investigators; Tavazzi, L; Maggioni, AP; Marchioli, R; Barlera, S; Franzosi, MG; Latini, R; Lucci, D et al. (August 2008). "Effect of n-3 polyunsaturated fatty acids in patients with chronic heart failure (the GISSI-HF trial): a randomised, double-blind, placebo-controlled trial". Lancet 372 (9645): 1223–30. doi:10.1016/S0140-6736(08)61239-8. PMID 18757090. http://linkinghub.elsevier.com/retrieve/pii/S0140-6736(08)61239-8.
- ^ a b Levy, Susan E.; Hyman, Susan L. (2005). "Novel treatments for autistic spectrum disorders". Ment Retard Dev Disabil Res Rev 11 (2): 131–142. doi:10.1002/mrdd.20062. PMID 15977319.
- ^ a b c Richardson, Alexandra J. (2006). "Omega-3 fatty acids in ADHD and related neurodevelopmental disorders". Int Rev Psychiatry 18 (2): 155–172. doi:10.1080/09540260600583031. PMID 16777670.
- ^ Green, VA; Pituch KA, Itchon J, Choi A, O'Reilly M, Sigafoos J (2006). "Internet survey of treatments used by parents of children with autism". Res Dev Disabil 27 (1): 70–84. doi:10.1016/j.ridd.2004.12.002. PMID 15919178.
- ^ Sinn, Natalie; Bryan, Janet (April 2007). "Effect of supplementation with polyunsaturated fatty acids and micronutrients on learning and behavior problems associated with child ADHD". J Dev Behav Pediatrics 28 (2): 82–91. doi:10.1097/01.DBP.0000267558.88457.a5. PMID 17435458.
- ^ Richardson, Alexandra J.; Montgomery, Paul (2005). "The Oxford-Durham study: a randomized, controlled trial of dietary supplementation with fatty acids in children with developmental coordination disorder". Pediatrics 115 (5): 1360–1366. doi:10.1542/peds.2004-2164. PMID 15867048.
- ^ Johnson M, Ostlund S, Fransson G, Kadesjö B, Gillberg C. (30 April 2008). "Omega-3/Omega-6 Fatty Acids for Attention Deficit Hyperactivity Disorder: A Randomized Placebo-Controlled Trial in Children and Adolescents". J Atten Disord 12 (5): 394–401. doi:10.1177/1087054708316261. PMID 18448859.
- ^ Bent, Stephen; Bertoglio, Kiah; Hendren, Robert L. (March 2009). "Omega-3 Fatty Acids for Autistic Spectrum Disorder: A Systematic Review". J Autism Dev Disord 39 (8): 1145–54. doi:10.1007/s10803-009-0724-5. PMC 2710498. PMID 19333748. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2710498.
- ^ Amminger, G. Paul et al. (2007). "Omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study". Biol Psychiatry 61 (4): 551–553. doi:10.1016/j.biopsych.2006.05.007. PMID 16920077.
- ^ Gilbert, Donald L. (2008). "Regarding 'omega-3 fatty acids supplementation in children with autism: a double-blind randomized, placebo-controlled pilot study'". Biol Psychiatry 63 (2): e13. doi:10.1016/j.biopsych.2007.03.028. PMID 17555722. Author reply: Amminger, G. Paul; Harrigan, Susan M. (February 2008). "Reply". Biol Psychiatry 63 (2): e15. doi:10.1016/j.biopsych.2007.04.002.
- ^ Olsen, Sjúrður Fróði; Secher, Niels Jørgen (2002-02-23). "Low consumption of seafood in early pregnancy as a risk factor for preterm delivery: prospective cohort study". BMJ (Clinical Research Ed.) 324 (7335): 447. doi:10.1136/bmj.324.7335.447. PMC 65663. PMID 11859044. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=65663.
- ^ Jensen, Craig L (2006). "Effects of n-3 fatty acids during pregnancy and lactation". Am J Clin Nutr 83 (6): 1452–1457. ISSN 0002-9165. http://www.ajcn.org/cgi/reprint/83/6/S1452.pdf.
- ^ Odent, Michel; Colson, Suzanne; De Reu, Paul (2002-05-25). "Consumption of seafood and preterm delivery : Encouraging pregnant women to eat fish did not show effect". BMJ (Clinical Research Ed.) 324 (7348): 1279. PMC 1123229. PMID 12028992. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1123229.
- ^ Puri, Basant K. (2006). "High-resolution magnetic resonance imaging sinc-interpolation-based subvoxel registration and semi-automated quantitative lateral ventricular morphology employing threshold computation and binary image creation in the study of fatty acid interventions in schizophrenia, depression, chronic fatigue syndrome, and Huntington's disease". Int Rev Psychiatry 18 (2): 149–154. doi:10.1080/09540260600583015. PMID 16777669.
- ^ http://www.scientificamerican.com/article.cfm?id=omega-3-deficiency-depression
- ^ Calabrese, J.R.; Rapport, D.J.; Shelton, M.D. (1999). "Fish oils and bipolar disorder: A promising but untested treatment". Arch Gen Psychiatry 56 (5): 413–414; discussion 415–416. doi:10.1001/archpsyc.56.5.413. PMID 10232295.
- ^ Stoll, A.L. et al. (1999). "Omega 3 fatty acids in bipolar disorder: A preliminary double-blind, placebo-controlled trial". Arch Gen Psychiatry 56 (5): 407–412. doi:10.1001/archpsyc.56.5.407. PMID 10232294.
- ^ Nemets, H.; Nemets, B.; Apter, A.; Bracha, Z.; Belmaker, R.H. (2006). "Omega-3 treatment of childhood depression: A controlled, double-blind pilot study". Am J Psychiatry 163 (6): 1098–1100. doi:10.1176/appi.ajp.163.6.1098. PMID 16741212.
- ^ Huan, M. et al. (2004). "Suicide attempt and n−3 fatty acid levels in red blood cells: a case control study in China". Biol Psychiatry 56 (7): 490–496. doi:10.1016/j.biopsych.2004.06.028. PMID 15450784. http://www.journals.elsevierhealth.com/periodicals/bps/article/PIIS0006322304007061/abstract.
- ^ http://article.psychiatrist.com/dao_1-login.asp?ID=10007556&RSID=69755683854317
- ^ Freeman MP, Hibbeln JR, Wisner KL, et al. (2006) Omega-3 fatty acids: evidence basis for treatment and future research in psychiatry. J Clin Psychiatry. 2006;67(12):1954-67. Free Full Text
- ^ Lewis, M. D.; Hibbeln, J. R.; Johnson, J. E.; Lin, Y. H.; Hyun, D. Y.; Loewke, J. D. (2011). "Suicide Deaths of Active-Duty US Military and Omega-3 Fatty-Acid Status". The Journal of Clinical Psychiatry. doi:10.4088/JCP.11m06879.
- ^ Lin, Pao-Yen; Kuan-Pin Su (July 2007). "A Meta-Analytic Review of Double-Blind, Placebo-Controlled Trials of Antidepressant Efficacy of Omega-3 Fatty Acids". J Clin Psychiatry 68 (7): 1056–1061. doi:10.4088/JCP.v68n0712. PMID 17685742. http://www.psychiatrist.com/privatepdf/2007/v68n07/.
- ^ Mischoulon D, Papakostas GI, Dording CM, et al. "A double-blind, randomized controlled trial of ethyl-eicosapentaenoate for major depressive disorder." J Clin Psychiatry. 25 August 2009. Abstract
- ^ Dietary intake of n-3 and n-6 fatty acids and the risk of clinical depression in women: a 10-y prospective follow-up study. Am J Clin Nutr. 2011 Jun;93(6):1337-43.
- ^ a b Food and Nutrition Board, Institute of Medicine of the National Academies (2005), pp.423
- ^ a b Food and Nutrition Board, Institute of Medicine of the National Academies (2005), pp.770
- ^ "Product Review: Omega-3 Fatty Acids (EPA and DHA) from Fish/Marine Oils". ConsumerLab.com. 2005-03-15. http://www.consumerlab.com/results/omega3.asp. Retrieved 2007-08-14.
- ^ Kris-Etherton, PM, Harris, WS, Appel LJ (2002). "Fish consumption, fish oil, omega-3 acids and cardiovascular disease". Circulation 106 (21): 2747–2757. doi:10.1161/01.CIR.0000038493.65177.94. PMID 12438303.
- ^ Falk-Petersen, S., S. et al. (1998). "Lipids and fatty acids in ice algae and phytoplankton from the Marginal Ice Zone in the Barents Sea". Polar Biology 20 (1): 41–47. doi:10.1007/s003000050274. ISSN 0722-4060. http://cat.inist.fr/?aModele=afficheN&cpsidt=2356641.
- ^ "Fish, Levels of Mercury and Omega-3 Fatty Acids". American Heart Association. http://www.americanheart.org/presenter.jhtml?identifier=3013797. Retrieved October 6, 2010.
- ^ Kris-Etherton, Penny M.; William S. Harris, Lawrence J. Appel (2002). "Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease". Circulation 106 (21): 2747–2757. doi:10.1161/01.CIR.0000038493.65177.94. PMID 12438303. http://circ.ahajournals.org/cgi/content/full/106/21/2747.
- ^ a b c d e f g h i j k l m n o p q r "Omega-3 Centre". Omega-3 sources. Omega-3 Centre. Archived from the original on 2008-07-18. http://web.archive.org/web/20080718174524/http://www.omega-3centre.com/sources_long_chain.html. Retrieved 2008-07-27.
- ^ "Pollutants found in fish oil capsules". BBC News. 2002-04-06. http://news.bbc.co.uk/1/hi/health/1911312.stm. Retrieved 2010-01-06.
- ^ Lawson, L.D.; Hughes, B.G. (1988). "Absorption of eicosapentaenoic acid and docosahexaenoic acid from fish oil triacylglycerols or fish oil ethyl esters co-ingested with a high-fat meal". Biochem. Biophys. Res. Commun. 156 (2): 960–963. doi:10.1016/S0006-291X(88)80937-9. PMID 2847723.
- ^ Beckermann, B.; Beneke, M.; Seitz, I. (1990). "Comparative bioavailability of eicosapentaenoic acid and docasahexaenoic acid from triglycerides, free fatty acids and ethyl esters in volunteers" (in German). Arzneimittel-Forschung 40 (6): 700–704. PMID 2144420.
- ^ Ulven SM; Kirkhus, B; Lamglait, A; Basu, S; Elind, E; Haider, T; Berge, K; Vik, H et al. (January 2011). "Metabolic Effects of Krill Oil are Essentially Similar to Those of Fish Oil but at Lower Dose of EPA and DHA, in Healthy Volunteers". Lipids 46 (1): 37–46. doi:10.1007/s11745-010-3490-4. PMC 3024511. PMID 21042875. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3024511.
- ^ Halpern, G.M., The Inflammation Revolution. Square City Publishers, New York 2005. ISBN 0-7570-0283-8
- ^ Lyprinol ® - Arthritis, Knee Pain, Anti-Inflammatory, Aching Joint Relief, Cardiovascular Health, Joint Health, Respiratory Health, Stiffness. "Lyprinol in Brief". Lyprinol.com. http://www.lyprinol.com/about1.htm. Retrieved 2011-01-03.
- ^ "Seed Oil Fatty Acids - SOFA Database Retrieval". http://sofa.bfel.de.
- ^ DeFilippis, Andrew P.; Laurence S. Sperling. "Understanding omega-3's" (PDF). Archived from the original on 22 October 2007. http://web.archive.org/web/20071022174611/http://www.biovita.fi/suomi/pdf/understanding_omega3.pdf. Retrieved 21 October 2007.
- ^ Wilkinson, Jennifer. "Nut Grower's Guide: The Complete Handbook for Producers and Hobbyists" (PDF). http://www.publish.csiro.au/samples/Nut%20Growers%20GuideSample.pdf. Retrieved 21 October 2007.
- ^ Bartram (1998), pp.271
- ^ "Egg Producers Deceive Consumers, Violate Law with Bogus Omega-3 Claims ~ Newsroom ~ News from CSPI ~ Center for Science in the Public Interest". Cspinet.org. 2007-06-21. http://www.cspinet.org/new/200706211.html. Retrieved 2011-01-03.
- ^ David Beaulieu. "Edible Landscaping With Purslane". About.com. http://landscaping.about.com/cs/weedsdiseases/a/purslane.htm.
- ^ "How Omega-6s Usurped Omega-3s In US Diet". http://www.medicalnewstoday.com/medicalnews.php?newsid=51575.
- ^ Trebunová, A.; Vasko, L.; Svedová, M.; Kasteľ, R.; Tucková, M.; Mach, P. (July 2007). "The influence of omega-3 polyunsaturated fatty acids feeding on composition of fatty acids in fatty tissues and eggs of laying hens". Deutsche Tierärztliche Wochenschrift 114 (7): 275–279. PMID 17724936.
- ^ Cherian, G. Effect of feeding full fat flax and canola seeds to laying hens on the fatty acids composition of eggs, embryos, and newly hatched chicks. http://www.fao.org/agris/search/display.do?f=./1991/v1717/US9138554.xml;US9138554
- ^ "Washington Post's Egg Taste Test Says Homegrown And Factory Eggs Taste The Same [UPDATED, POLL]". Huffingtonpost.com. http://www.huffingtonpost.com/2010/06/03/egg-taste-test-says-no-di_n_599286.html. Retrieved 2011-01-03.
- ^ http://www.nature.com/nature/journal/v187/n4736/abs/187511b0.html
- ^ Duckett, S. K., D. G. Wagner, et al. (1993). "Effects of time on feed on beef nutrient composition." J Anim Sci 71(8): 2079-88.
- ^ "Specially Labeled Lamb". http://www.sheep101.info/labeledlamb.html.
- ^ Azcona, J.O., Schang, M.J., Garcia, P.T., Gallinger, C., R. Ayerza (h), and Coates, W. (2008). "Omega-3 enriched broiler meat: The influence of dietary alpha-linolenic omega-3 fatty acid sources on growth, performance and meat fatty acid composition". Canadian Journal of Animal Science, Ottawa, Ontario, Canada, 88:257-269.
- ^ "Gourment Game - Amazing Nutrition Facts". http://www.macromeats-gourmetgame.com.au/Nutrition/AmazingNutritionFacts.aspx.
- ^ "DHA in Brain and Retina Structure". http://www.dha-in-mind.com/Portals/0/PDF%20Files/DHA_inbrain_and_retinastructure.pdf.
- ^ "Nutrition for the Brain". http://surfer.nmr.mgh.harvard.edu/ftp/articles/caudatecomm.pdf.
- ^ "Natural Health Product Monograph - Seal Oil [Health Canada, 2009]". Hc-sc.gc.ca. http://www.hc-sc.gc.ca/dhp-mps/prodnatur/applications/licen-prod/monograph/mono_seal_oil_huile_phoque-eng.php. Retrieved 2011-01-03.
- ^ European Parliament (9 November 2009). "MEPs adopt strict conditions for the placing on the market of seal products in the European Union". Hearings. European Parliament. http://www.europarl.europa.eu/sides/getDoc.do?pubRef=-//EP//TEXT+IM-PRESS+20090504IPR54952+0+DOC+XML+V0//EN. Retrieved 12 March 2010.
- ^ Journal of Dairy Science, 2006. 89:1956–1969. “The Linear Relationship between the Proportion of Fresh Grass in the Cow Diet, Milk Fatty Acid Composition, and Butter Properties”
- Bartram, Thomas, 1998, Bartram's Encyclopedia of Herbal Medicine, p. 271.[Full citation needed]
- Bell, J.G.; MacKinlay, EE; Dick, JR; MacDonald, DJ; Boyle, RM; Glen, AC (2004). "Essential fatty acids and phospholipase A2 in autistic spectrum disorders". Prostaglandins Leukot.Essent.Fatty Acids 71 (4): 201–204. doi:10.1016/j.plefa.2004.03.008. PMID 15301788.
- Cunnane SC (2006). "Survival of the fattest: the key to human brain evolution". Medécine/Sciences : M/S 22 (6–7): 659–63. doi:10.1051/medsci/20062267659. PMID 16828044.
- Food and Nutrition Board, Institute of Medicine of the National Academies (2005). Dietary Reference Intakes For Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington, DC: The National Academies Press. ISBN 0-309-08537-3. http://newton.nap.edu/books/0309085373/html/770.html.
- Hibbeln JR, Nieminen LR, Blasbalg TL, Riggs JA, Lands WE.(2006). "Healthy intakes of n−3 and n−6 fatty acids: estimations considering worldwide diversity". Am J Clin Nutr. 83(6 Suppl):1483S–1493S.
- Lands, William E.M. "Fish, Omega-3 and Human Health" Champaign. AOCS Press. 2005 ISBN 1-893997-81-2
- Ohara, K. (2007). "The n−3 polyunsaturated fatty acid/dopamine hypothesis of schizophrenia". Prog Neuropsychopharmacol Biol Psychiatry 31 (2): 469–474. doi:10.1016/j.pnpbp.2006.11.013. PMID 17184889.
- Richardson, A.J.; Ross, M.A. (2000). "Fatty acid metabolism in neurodevelopmental disorder: a new perspective on associations between attention-deficit/hyperactivity disorder, dyslexia, dyspraxia and the autistic spectrum". Prostaglandins Leukot.Essent.Fatty Acids 63 (1–2): 1–9. doi:10.1054/plef.2000.0184. PMID 10970706.
- Robson, A. (2006). "Shellfish view of omega-3 and sustainable fisheries". Nature 444 (7122): 1002. doi:10.1038/4441002d. http://www.nature.com/doifinder/10.1038/4441002d.
- Robson, A. (2007). "Preventing the diseases of civilisation: shellfish, the omega-3:6 balance and human health". Shellfish News 23: 25–27. http://www.cefas.co.uk/publications/shellfishnews/sfn23.pdf.
- Scher, J.; Pillinger, M. (2005). "15d-PGJ2: The anti-inflammatory prostaglandin?". Clinical Immunology 114 (2): 100–109. doi:10.1016/j.clim.2004.09.008. PMID 15639643.
- Tribole, Evelyn. "The Ultimate Omega-3 Diet" New York. McGraw-Hill. 2007 ISBN 13:978-0-07-146986-9
- Young, G.; Conquer, J (2005). "Omega-3 fatty acids and neuropsychiatric disorders". Reprod.Nutr.Dev 45 (1): 1–28. doi:10.1051/rnd:2005001. PMID 15865053.
- Allport, Susan. The Queen of Fats: Why Omega-3s Were Removed from the Western Diet and What We Can Do to Replace Them. University of California Press, September 2006. ISBN 978-0-520-24282-1.
- Boyd, Hillary & Basant, Puri K. The Natural Way to Beat Depression: the groundbreaking discovery of EPA to change your life. London. Hodder and Stoughton. 2004. ISBN 0-340-82497-2
- Chow, Ching Kuang. Fatty Acids in Foods and Their Health Implications. Routledge Publishing. New York, New York. 2001.
- Clover, Charles. The End of the Line: How overfishing is changing the world and what we eat. Ebury Press, London 2004. ISBN 0-09-189780-7
- Erasmus, Udo. Fats That Heal, Fats That Kill. 3rd ed. Burnaby (BC): Alive Books; 1993.
- Smithers, Lois. The Food Industry's Greed. How Misleading Labeling of Omega-3 Foods Undermines American Health.
- Stoll, Andrew L. The Omega-3 Connection. Simon & Schuster 2001. ISBN 0-684-87138-6.
- DHA/EPA Omega-3 Institute Organization founded to educate health professionals and the public about omega-3
- American Heart Assoc "Fish & Omega-3 Fatty Acids"
- BBC News report: Oily fish helps cut inflammation, March 12, 2005.
- University of Maryland Medical Center, omega-3 Fatty Acids
- Durham Research: Using Fatty Acids for Enhancing Classroom Achievement Website for the Durham Schools Trial, trial on the effects of fatty acids with children who were under performing in class. Funded by the Durham City Council and Oxford University. Their initial results (also available on durhamtrial.org) were published in May 2005.
- Essential (Omega-3 and Omega-6) Fatty Acids: The Linus Pauling Institute Micronutrient Information Center
- Simopoulos, AP The importance of the ratio of omega-6/omega-3 essential fatty acids.
- MedlinePlus Herbs and Supplements: Omega-3 fatty acids, fish oil, alpha-linolenic acid
- Another reason why men like curves (Daily Telegraph) Omega-3 credited with shaping a woman's figure to be more attractive to men.
- Long-Chain Polyunsaturated Fatty Acids in Human Brain Evolution. Crawford M.A. In: Environmental Influences on Human Brain Evolution. Cunnane, S. / Stewart, K. (eds.)
Types of lipids General Geometry Fatty acids Phospholipids Cholesterol/steroidsCorticosteroids · Sex steroids Sphingolipids Eicosanoids Antidepressants (N06A) Specific reuptake inhibitors (RIs), enhancers (REs), and releasing agents (RAs)Serotonin–norepinephrine–dopamine reuptake inhibitors (SNDRIs)Dopamine reuptake inhibitors (DRIs)Norepinephrine-dopamine releasing agents (NDRAs)Serotonin-norepinephrine-dopamine releasing agents (SNDRAs)OthersIndeloxazine • Teniloxazine • Tramadol • Viqualine Receptor antagonists and/or reuptake inhibitorsSerotonin antagonists and reuptake inhibitors (SARIs)Serotonin modulators and stimulators (SMSs)Vortioxetine Tricyclic and tetracyclic antidepressants (TCAs/TeCAs)TricyclicsAmezepine • Amineptine • Amitriptyline# • Amitriptylinoxide • Azepindole • Butriptyline • Cianopramine • Clomipramine • Cotriptyline • Cyanodothiepin • Demexiptiline • Depramine/Balipramine • Desipramine • Dibenzepin • Dimetacrine • Dosulepin/Dothiepin • Doxepin • Enprazepine • Fluotracen • Hepzidine • Homopipramol • Imipramine • Imipraminoxide • Intriptyline • Iprindole • Ketipramine • Litracen • Lofepramine • Losindole • Mariptiline • Melitracen • Metapramine • Mezepine • Naranol • Nitroxazepine • Nortriptyline • Noxiptiline • Octriptyline • Opipramol • Pipofezine • Propizepine • Protriptyline • Quinupramine • Tampramine • Tianeptine • Tienopramine • Trimipramine; Monoamine oxidase inhibitors (MAOIs)NonselectiveMAOA-SelectiveIrreversible: Clorgiline; Reversible: Amiflamine • Bazinaprine • Befloxatone • Befol • Brofaromine • Cimoxatone • Esuperone • Harmala Alkaloids (Harmine, Harmaline, Tetrahydroharmine, Harman, Norharman, etc) • Methylene Blue • Metralindole • Minaprine • Moclobemide • Pirlindole • Sercloremine • Tetrindole • Toloxatone • Tyrima;MAOB-Selective Azapirones and other 5-HT1A receptor agonists Mood stabilizers Mood disorder (F30–F39, 296) History Symptoms Spectrum TreatmentOther mood stabilizersNon-pharmaceutical Related
Wikimedia Foundation. 2010.
Look at other dictionaries:
omega-3 (fatty acid) — [ō mā′gəthrē′] n. a type of polyunsaturated fatty acid in fish oil, shellfish, soybeans, etc., linked to low cholesterol and low LDL levels * * * … Universalium
omega-3 (fatty acid) — [ō mā′gəthrē′] n. a type of polyunsaturated fatty acid in fish oil, shellfish, soybeans, etc., linked to low cholesterol and low LDL levels … English World dictionary
omega-3 (fatty acid) — [ō mā′gəthrē′] n. a type of polyunsaturated fatty acid in fish oil, shellfish, soybeans, etc., linked to low cholesterol and low LDL levels … English World dictionary
Omega-6 fatty acid — For an explanation of n and numerical nomenclature (such as n−6 or 18:2), see Fatty acid#Nomenclature. Types of fats in food Unsaturated fat Monounsaturated fat Polyunsaturated fat Trans fat Cis fat Omega fatty acids: ω−3 ω−6 ω−9 Saturated fat… … Wikipedia
Omega-9 fatty acid — For an explanation of n and numerical nomenclature (such as n−9 or 18:1), see Fatty acid#Nomenclature. Types of fats in food Unsaturated fat Monounsaturated fat Polyunsaturated fat Trans fat Cis fat Omega fatty acids: ω−3 ω−6 ω−9 Saturated fat… … Wikipedia
omega-3 fatty acid — noun a polyunsaturated fatty acid whose carbon chain has its first double valence bond three carbons from the beginning • Syn: ↑omega 3 • Hypernyms: ↑polyunsaturated fatty acid • Hyponyms: ↑alpha linolenic acid, ↑docosahexaenoic acid, ↑ … Useful english dictionary
omega-3 fatty acid — noun any polyunsaturated fatty acid having a double bond between the third and fourth carbon atoms from the end of the molecule farthest from the carboxylic acid; they are found in green vegetables and in the oils of fish such as salmon and… … Wiktionary
omega-6 fatty acid — noun a polyunsaturated fatty acid whose carbon chain has its first double valence bond six carbons from the beginning • Syn: ↑omega 6 • Hypernyms: ↑polyunsaturated fatty acid • Hyponyms: ↑linolenic acid … Useful english dictionary
omega-3 fatty acid — /oh mee geuh three , oh may , oh meg euh / a polyunsaturated fatty acid, essential for normal retinal function, that influences various metabolic pathways, resulting in lowered cholesterol and triglyceride levels, inhibited platelet clotting, and … Universalium
omega-6 fatty acid — noun any polyunsaturated fatty acid having a double bond between the sixth and seventh carbon atoms from the end of the molecule farthest from the carboxylic acid; although they are essential fatty acids, there is evidence that excess levels can… … Wiktionary