LONDON—Increased supplementation of omega-3 long-chain polyunsaturated fatty acids (PUFAs) do not benefit cognitive health in older adults, according to a new study from researchers at the London School of Hygiene Tropical Medicine published in the American Journal of Clinical Nutrition.
Researchers conducted a double blind control trial of 867 cognitively healthy adults, aged 70 to 79, from 20 general practices in England and Wales who were given daily capsules providing 200 mg of eicosapentaenoic acid (EPA) plus 500 mg of docosahexaenoic acid (DHA) or olive oil for 24 months. Trained research nurses administered a battery of cognitive tests, including the primary outcome, the California Verbal Learning Test (CVLT), at baseline and 24 months. Intention-to-treat analysis of covariance, with adjustment for baseline cognitive scores, age, sex, and age at leaving full-time education, included 748 (86 percent) individuals who completed the study.
The mean age of participants was 75 years; 55 percent of the participants were men. Withdrawals and deaths were similar in active (n=49 and n= 9, respectively) and placebo (n=53 and n=8, respectively) arms. Mean (±SD) serum EPA and DHA concentrations were significantly higher in the active arm than in the placebo arm at 24 months. There was no change in cognitive function scores over 24 months, and intention-to-treat analysis showed no significant differences between trial arms at 24 months in the CVLT or any secondary cognitive outcome.