Fish tales

Omega 3 fatty acids have long been touted as a miracle ingredient that can deliver all number of health benefits. Next Generation Food takes a look at some of the latest claims to be proven and dismissed.

Awareness of the potential health benefits of Omega 3 fatty acids started back in the 1930s and has improved dramatically since the discovery of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in the 1970s. The discovery was made by two Danish medical scientists – Dr. Hans Olaf Bang and Dr. Jørn Dyerberg – who voyaged to Greenland to investigate the mysteriously low incidence of heart disease amongst native Inuits in spite of a diet rich in meat and fat, or blubber.

The researchers reported their findings in The Lancet in 1971 and since that moment over 14,000 papers have been published on omega-3 including close to 8000 human studies, according to Dr Dyerberg.

In recent years there has been a veritable explosion of omega 3 in science and the marketplace. However, one of the most recent debates surrounding Omega 3 also harps back to current discussions over health claims.

An international consortium of lipid scientists are concerned over the fact that food companies can claim their products are rich in Omega 3 irrespective of whether these are long chain - EPA and DHA - or short-chain molecules. The difference is that long-chain Omega 3 is derived from expensive sources such as fish, whilst the short-chain variety come from plant oils and leafy green vegetables and are said to be far less beneficial. 

Lipid biologists are also concerned over EFSA's recommendations for daily intake of Omega 3. Currently set at 250mg per day, the scientists believe that this is too low and suggest a figure nearer to 566mg per day based on the average of 15 studies conducted on the matter.

Whilst these debates are on-going consumers are being bombarded with information regarding the latest studies concerning Omega 3 and its health benefits. Here we take a look at some of the latest studies to be published.

Cognitive health

An 18-month government-backed study was conducted in the USA recently, led by Dr Joseph Quinn of Oregon Health and Sciences University in Portland. The study examined the potential of DHA supplements to treat Alzheimer's disease and the findings suggested that taking Omega 3 fatty acid supplements does not arrest Alzheimer's in people who already developed the disease but it can help to restore mental acuity in people suffering from slight memory complaints.

Joint health

A study from Germany, published in the journal Advances in Therapy states that combining Omega 3 fatty acids with glucosamine achieves better improvements in joint health than glucosamine alone. Lead author of the study, Dr Joerg Gruenwald, and team selected 177 people with differing degrees of hip or knee osteoarthritis and randomly assigned them to receive either a glucosamine sulphate supplement or glucosamine plus Omega 3. After 26 weeks, the pain levels of the participants were tested using the established Western Ontario and McMaster Universities Arthrosis index (WOMAC) score. Results showed that the combination product reduced morning stiffness and pain in the hips and knees by between 48.5 and 55.6 percent, compared to 41.7 to 55.3 percent in the glucosamine only group.

Cardiovasular health

A new study by the Danish Diet, Cancer and Health cohort reported that increased intake of EPA, DPA and DHA omega 3 fatty acids may protect men against acute coronary syndrome (ACS). The study, which was published in the British journal of Nutrition, involved 57,053 men and women and showed that over an average follow-up time of almost eight years, 1150 people developed ACS. Men who consumed more than 0.39 grams of polyunsaturated fatty acids per day had an associated risk of ACS 27 percent lower than men who consumed less than 0.39 grams a day. The researchers noted that no benefits were observed for women

Ocular health

The US National Eye Institute recently conducted a study which found that increased intakes of Omega 3 fatty acids may reduce the risk of developing age-related blindness by 30 percent. The researchers, led by John Paul SanGiovanni, said that the results of the study may guide the development of low-cost and easily implemented preventative interventions for progression to advanced age-related macular degeneration.

Weight watching

Finding reported in the British Journal of Nutrition indicate that Omega 3 fatty acids could help to lower body weight. The study, led by Professor Monohar Garg from the University of Newcastle and president elect of the Nutrition Society of Australia, shows that fish oils could play an instrumental role in weight management. The investigations found that overweight and obese people have blood levels of Omega 3 almost one percent lower than people of a healthy weight. Professor Garg and his co-workers concluded that more intervention trials in adults examining the influence of dietary supplementation with Omega 3 fatty acids to assist weight loss and weight maintenance is necessary to ascertain whether the link is causal or correlation.   

Mental health

Past studies have shown that in depressed psychiatric patients who are otherwise medically well, augmentation with omega-3 fatty acids dramatically improves the efficacy of antidepressants. However, a new study conducted by Robert M Carney of Washington University School of Medicine and published in the Journal of the American Medical Association (JAMA), shows that augmenting antidepressant therapy with an Omega 3 supplement does not result in improvement of levels of depression in those patients who suffer from coronary heart disease.

Cancer claim

A new study presented in Clinical Cancer Research, a journal of the American Association for Clinical Cancer Research, suggests that diets high in Omega 3 EPA and DHA may decrease the risk of prostate cancer. In the study, researchers from the University of California, San Francisco, looked at 466 men with aggressive prostate cancer and 478 healthy men, assessing their eating habits using a food frequency questionnaire. The men were also screened for a variant of a gene known as COX-2, which is known to increase the risk of developing prostate cancer.

The results showed that men who ate dark, fatty fish one to three times per month had a 36 percent lower risk of prostate cancer as compared to those who had zero dark fish consumption. Furthermore, those who ate dark fish at least once a week had a 57 percent risk reduction. And, those who consumed little to no Omega-3 EPA/DHA and who also carried the specific COX-2 variant, were five times more likely to develop advanced prostate cancer. However, this association was essentially reversed with increasing consumption of Omega-3 EPA/DHA.