3 fatty acid treatment in 174 patients with mild to moderate alzheimer disease: Omegad study: A randomized double-blind trial

Background Epidemiologic and animal studies have suggested that dietary fish or fish oil rich in -3 fatty acids, for example, docosahexaenoic acid and eicosapentaenoic acid, may prevent Alzheimer disease (AD). Objective To determine effects of dietary -3 fatty acid supplementation on cognitive functions in patients with mild to moderate AD. Design Randomized, double-blind, placebo-controlled clinical trial. Participants Two hundred four patients with AD (age range [mean \ub1 SD], 74 \ub1 9 years) whose conditions were stable while receiving acetylcholine esterase inhibitor treatment and who had a Mini-Mental State Examination (MMSE) score of 15 points or more were randomized to daily intake of 1.7 g of docosahexaenoic acid and 0.6 g of eicosapentaenoic acid (-3 fatty acid\u96treated group) or placebo for 6 months, after which all received -3 fatty acid supplementation for 6 months more. Main Outcome Measures The primary outcome was cognition measured with the MMSE and the cognitive portion of the Alzheimer Disease Assessment Scale. The secondary outcome was global function as assessed with the Clinical Dementia Rating Scale; safety and tolerability of -3 fatty acid supplementation; and blood pressure determinations. Results One hundred seventy-four patients fulfilled the trial. At baseline, mean values for the Clinical Dementia Rating Scale, MMSE, and cognitive portion of the Alzheimer Disease Assessment Scale in the 2 randomized groups were similar. At 6 months, the decline in cognitive functions as assessed by the latter 2 scales did not differ between the groups. However, in a subgroup (n =3D 32) with very mild cognitive dysfunction (MMSE >27 points), a significant (P<.05) reduction in MMSE decline rate was observed in the -3 fatty acid\u96treated group compared with the placebo group. A similar arrest in decline rate was observed between 6 and 12 months in this placebo subgroup when receiving -3 fatty acid supplementation. The -3 fatty acid treatment was safe and well tolerated. Conclusions Administration of -3 fatty acid in patients with mild to moderate AD did not delay the rate of cognitive decline according to the MMSE or the cognitive portion of the Alzheimer Disease Assessment Scale. However, positive effects were observed in a small group of patients with very mild AD (MMSE >27 points)