PUFAs and risk of cognitive decline or dementia: epidemiological data

Abstract

The potential role of dietary poly-unsaturated fatty acids (PUFA) in the prevention of dementia and Alzheimer’s disease arouses increasing interest. Fatty fish is very rich in long-chain n-3 PUFA, in particular in DHA which is also a major component of neuron membranes. The Rotterdam Study, the French PAQUID and Three-City studies, and the Chicago Health and Aging Project found a protective effect of fish or long-chain n-3 PUFA consumption against dementia or cognitive decline. In the Three-City Study we showed that regular use of omega3 rich oils was also associated with a decreased risk of borderline significance for all cause dementia. Biological data are congruent with the results obtained with dietary data. No intervention study evaluating the effect of n-3 PUFA in the primary prevention of dementia in human has been published. Despite the negative results of the OmegAD intervention trial in patients with moderate AD, these results considered all together suggest a protective effect of long-chain n-3 PUFA against cognitive decline and dementia. However, the complex mechanisms of action of PUFA at the different stages of brain aging and their interaction with the apolipoprotein E genotype still have to be elucidated.

Keywords

• nutrition
• fatty acids
• dementia
• Alzheimer
• cognition
• epidemiology