Indication:

Alzheimer's disease (AD)

Source:

Arch Neurol, October 2006;63:1402-1408.

Research:

Epidemiologic and animal studies have suggested that dietary fish or fish oil rich in omega 3 fatty acids, for example, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), may prevent Alzheimer's disease (AD). To test this, investigators conducted a randomized, double-blind, placebo-controlled clinical trial. Participants in the study included 204 patients with AD between the ages of 74 and 79, 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. They were randomized to daily intake of 1.7 grams of DHA and 0.6 grams of EPA or placebo for 6 months, after which all received omega 3 fatty acid supplementation for 6 months more. 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 omega 3 fatty acid supplementation; and blood pressure determinations.

Results:

One hundred seventy-four patients completed the trial. At baseline, mean values for the Clinical Dementia Rating Scale, MMSE, and cognitive portion of the Alzheimer Disease Assessment Scale in the two randomized groups were similar. At 6 months, the decline in cognitive functions as assessed by the latter two scales did not differ between the groups. However, in a subgroup (n=32) with very mild cognitive dysfunction (MMSE >27 points), a significant reduction in MMSE decline rate was observed in the omega 3 fatty acid–treated 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 omega 3 fatty acid supplementation. Researchers concluded that administration of omega 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, they said, positive effects were observed in a small group of patients with very mild AD (MMSE >27 points).