Nutrient - Can omega-3 fatty acids help to fight against depression?
Scientists are beginning to show that the foods we eat not only influence our physical health but can also affect our mental health, too. Many of us feel down from time-to-time, which is a normal part of life. However, for some, the feelings of helplessness, hopelessness and worthlessness just won’t go away and, instead, become overwhelming and disabling. What they are likely to be experiencing is an episode of clinical depression. It’s estimated that between 8-12% of the UK population experience depression in any year and that over a lifetime we have a 20%, or one in five, chance of suffering an episode of depression.
Some studies have shown that certain nutrients may help to protect the brain and ward off mental disorders. Omega 3 fatty acids are an example of such nutrients, where dietary deficiency in humans has been associated with an increased risk of mood disorders, including depression. The problem is that some of the evidence supporting the benefits of omega 3 fatty acids has been inconclusive and a few of the studies are of questionable experimental design and scientific validity.
However, a recent, randomised, double-blind, placebo-controlled clinical study, which is the largest so far to look at the effects of omega 3 fatty acids in treating major depression, has provided encouraging results. Dr François Lespérance, of the University of Montreal in Canada, and his colleagues randomly assigned 432 participants, who had been diagnosed with at least moderate depression, into two groups. One group took fish oil capsules containing a high ratio of EPA to DHA (providing 1,050mg/day EPA and 150mg/day DHA) and the other group took a placebo containing sunflower oil. After eight weeks, only those in the fish oil group, who did not also have anxiety disorders, showed marked improvements in their depression, compared to those receiving the placebo.
Although much more work needs to be done to determine the role of fish oil in the treatment of depression and, in particular, how the effects of omega 3 fatty acids compare to conventional anti-depressants, the results are a tantalising suggestion of how omega 3 fatty acids could have beneficial effects on our mood and provide a potentially safe therapeutic strategy for depression.
Lespérance F, Frasure-Smith N, St-André E, Turecki G, Lespérance P, and Wisniewski SR. The efficacy of omega-3 supplementation for major depression: a randomized controlled trial. J Clin Psychiatry 2010; [Epub ahead of print].