High EPA plasma levels are associated with a lower risk of Alzheimer’s disease
The neuroprotective properties of polyunsaturated fatty acids (PUFAs) are well established (especially for docosahexaenoic acid (DHA)) and there is growing evidence to support its protective effect in Alzheimer’s disease.
The 2018 Alzheimer's Association International Conference, held in Chicago, saw the presentation of the results from a prospective, multicentre study that included 1,272 participants without dementia and 67 with Alzheimer’s disease aged 75 or over ( from the German AgeCoDe study, with the participation of primary care patients over 75).
The aim was to investigate whether plasma concentrations of 25 monounsaturated or polyunsaturated acids, combinations of them (e.g. DHA and eicosapentaenoic acid (EPA)) and the ratios between them (e.g. omega-6:omega-3) were related to previously diagnosed Alzheimer’s disease in over-75s. It also analysed whether PUFAs were associated with the risk of incidence of Alzheimer’s disease after a 7-year follow-up.
The results showed a significant relationship between plasma concentrations of EPA and DHA, total PUFA, total omega-3 PUFA, the joint total of EPA and DHA and the omega-6:omega-3 ratio and Alzheimer’s disease, after adjusting the analysis for age, sex, apolipoprotein E ε4 alelle, body weight, total cholesterol and triglycerides, hypertension, diabetes, depression, transient ischaemic accident, hyperlipidaemia and hypolipidaemic medication.
After a 7-year follow-up, 191 participants in the non-dementia group developed Alzheimer’s disease. A higher proportion of plasma EPA was associated with a lower incidence of Alzheimer’s, which did not occur with DHA. This led the investigators to conclude that changes in diet at the onset of Alzheimer’s disease could affect the bioavailability of these fatty acids.