O. (Ondine) van de Rest: “Fish fatty acids and mental health in older people”

Fish fatty acids for a better mental health?
The population of older people is growing rapidly and so is the number of age-related diseases such as dementia and depression. It has been suggested that the intake of fish and fish fatty acids could protect against age-related cognitive decline, dementia and impaired mental well-being. Fish fatty acids are omega-3 polyunsaturated fatty acids, i.e. eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Main sources are fatty fish such as salmon, herring or mackerel. The aim of this thesis was to investigate the effect of fish and EPA+DHA intake on cognitive performance and mental well-being in older people.

We examined the effect of daily supplementation with a high or a low dose of EPA+DHA during 6 months on cognitive performance and mental well-being. We did this by means of an intervention study where 302 individuals aged 65 years or older consumed a high or a low dose of EPA+DHA or placebo capsules. In this study the extra EPA+DHA did not affect cognitive performance or mental well-being. We also investigated whether the intake of fish and EPA+DHA was associated with mental health in different aging populations. We found no association between fish intake and cognitive performance or mental well-being in these populations. Based on this thesis and the total evidence in the field, we conclude that the beneficial effect of fish fatty acids on mental health in the general population still needs to be established.