Research paper

Docosahexaenoic acid supplementation and cognitive decline in Alzheimer disease: a randomized trial.

JAMA

Nov 2010

DOI: 10.1001/jama.2010.1510

Citations: 766

Influential: 37

Interventional (Human) Studies

Study answer

What this study found

DHA supplementation did not slow cognitive or functional decline in mild to moderate Alzheimer disease. The primary outcomes were not significant: ADAS-cog P=.41 and CDR sum of boxes P=.68; ADCS-ADL P=.38 and NPI P=.11 were also null. An APOE ε4-negative subgroup showed less ADAS-cog decline with DHA than placebo (6.23 points [95% CI, 4.08 to 8.38] vs 10.11 points [95% CI, 7.12 to 13.10]; P=.03), but this did not alter the overall conclusion that DHA provided no clinical benefit.

Study & population: Randomized, placebo-controlled trial in adults with probable mild to moderate Alzheimer disease recruited from 51 US centers.
Intervention: Oral algal-derived docosahexaenoic acid (DHA) was given as 1 g per capsule twice daily for a total dose of 2 g/day for 18 months, compared with placebo.
Key limitation: The trial was limited to 18 months and the overall result was null despite a favorable subgroup signal in APOE ε4-negative participants.

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Original abstract

CONTEXT Docosahexaenoic acid (DHA) is the most abundant long-chain polyunsaturated fatty acid in the brain. Epidemiological studies suggest that consumption of DHA is associated with a reduced incidence of Alzheimer disease. Animal studies demonstrat…