The number of brain-related conditions is increasing in our society — think of Alzheimer's and Parkinson's, but also of depression. More and more research shows that omega 3 fatty acids have a beneficial effect on mental health. How is that possible? Can a supplement then help against low mood? We turned to dr. ir. Eric De Maerteleire, author of several books on health and healthy nutrition, for some clarification.
The omega 3 fatty acids at the heart of this are EPA and DHA?
That's right. Omega 3 fatty acids are mainly found in fish oil and certain sea algae. Because depression is less common in countries where people eat a lot of fish, scientists have investigated whether fish oil can prevent and/or treat depression and other mood disorders. Two omega 3 fatty acids — eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) — are thought to have the greatest potential to help people with mood disorders.
It is important, however, to distinguish between the prevention and the treatment of depression. The most beneficial effects have been observed in prevention. In fact, omega 3 fatty acids play an important preventive role at every age.
Fish fatty acids are important for the development of the brain and for good eyesight. The omega 3 fatty acid DHA is an important component of the brain and of the retina. Once the brain is fully developed, the need for DHA is smaller and the excess will be oxidised into carbon dioxide. Fish consumption by the pregnant woman is therefore very important for the development of the brain of the unborn or newborn child (lactation period). Research further shows that women who have several children in quick succession suffer less from postnatal depression if, between and during pregnancies, the supply of fish fatty acids proceeds in an adequate manner (900 mg/day).
In older people, it has been found that a sufficient intake of omega 3 fatty acids reduces the chance of neurodegenerative diseases (dementia, Alzheimer's disease, Parkinson's disease), strengthens cognitive ability and reduces the chance of depression. Memory works better and people feel more alert and cheerful. One study, for example, found that eating at least 2 portions of fish per week was associated with a 10% lower risk of dementia and a 30% lower risk of Alzheimer's disease. Another study from 2020 concluded that eating fish can improve memory, promote brain function and protect brain structure in healthy adults.
The effects on children have also been fairly well studied. In double-blind, placebo-controlled research, beneficial effects have been found on the onset and development of ADHD, autism, dyspraxia, dyslexia and aggressiveness.
Can omega 3 also serve as a treatment for depression?
More than 30 clinical studies have tested various omega 3 preparations in people with depression.
When used alongside antidepressants, the effect is often limited.
Studies with omega 3 alone generally use EPA or EPA+DHA in doses of 0.5 to 10 grams per day. For comparison: a daily intake of 1 gram corresponds to eating 100 grams of salmon three times a week.
Meta-analyses suggest effectiveness, but results vary due to differences in dosage and EPA/DHA ratios.
The best results come from formulas with at least 60% EPA, especially as a supplementary treatment for depression.
New research points to benefits in ADHD, but not in schizophrenia. Depressed people who are overweight and have increased inflammatory activity, as well as children and adolescents, seem to benefit additionally from EPA therapy.
Although there are conflicting results, the general consensus does nevertheless appear to be that there is a clear effect of the consumption of omega 3 fatty acids on mental health.
Can omega 3 fatty acids also help with other mental health conditions?
Well, omega 3 fatty acids have been studied in various mood disorders, such as postnatal depression, with promising results. In bipolar disorder (manic depression), omega 3 fatty acids may be most effective for the depressive phase rather than the manic phase of the illness. Omega 3 fatty acids have also been proposed to relieve or prevent other psychiatric conditions, including schizophrenia, borderline personality disorder, obsessive compulsive disorder and attention deficit disorder. However, there is still not enough evidence to recommend omega 3 fatty acids for these conditions.
Do omega 3 supplements also have side effects?
Omega 3 fatty acids are generally safe and well tolerated. Stomach complaints and a "fishy taste" are the most common complaints, but they now occur less often thanks to production methods that reduce impurities. Earlier concerns about omega 3 fatty acids increasing the risk of bleeding have largely been refuted, but caution is still advised in people who use blood thinners or who are about to undergo surgery.
Caution is advised in people with bipolar disorder to prevent them from slipping into a manic state.
Because omega 3 fatty acids are important for the development of the brain and pregnancy depletes omega 3 in expectant mothers, taking supplements should, in theory, benefit pregnant women and their children. Fish consumption during pregnancy is supported by the FDA, but because we have no long-term data on the safety or optimal dosage of omega 3 fatty acids during pregnancy, expectant mothers should consider taking omega 3 supplements wisely. For this group of people, eating fatty fish species is therefore a better option.
Conclusions
Omega 3 fatty acids derived from fatty fish are indispensable for good health in many areas. This also applies to mental health.
The strongest effects probably lie in the area of prevention, and this should already take place in the womb, because fish omega 3 fatty acids are of very great importance for the formation and the functioning of the brain in the unborn child. A pregnant woman should therefore eat enough fatty fish.
Omega 3 fatty acids are promising natural treatments for mood disorders. However, more research is needed into how they work, how effective they really are and their long-term safety before definitive recommendations can be made for people with mental health problems or who want to improve their mood. In some cases a positive effect is observed, in other studies not. This is not surprising, because carrying out such studies is not always straightforward, also for ethical reasons, and there may be interference from other eating and lifestyle habits.
For daily practice, it is very important to eat enough fatty fish: 150 to 300 grams per week. These are species such as mackerel, salmon, herring, sprat, young herring, sardines, etc. Psychiatrist and leading researcher Roel Mocking from the Netherlands puts it as follows: 'Omega 3 fatty acids are not a panacea, but they are part of a healthy diet, especially in the form of regular fatty fish'.
For people who absolutely do not like fatty fish, supplements can be interesting. A daily dose of 500 mg (a combination of EPA and DHA) is then usually sufficient. People who eat vegetarian or vegan should certainly be alert to deficiencies in these important fatty acids.
Source: Sofie Van Rossom, health journalist