DHA & Dementia

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Archives Of Neurology

Vol. 63 No. 11, November 2006

Plasma Phosphatidylcholine Docosahexaenoic Acid

Content and Risk of Dementia and Alzheimer Disease

The Framingham Heart Study

Ernst J. Schaefer, MD; Vanina Bongard, MD, PhD; a

S. Beiser, PhD; Stefania Lamon-Fava, MD, PhD; Sander

J. Robins, MD; Rhoda Au, PhD; L. Tucker,

PhD; J. , PhD; W. F. , MD;

Philip A. Wolf, MD

Arch Neurol. 2006;63:1545-1550.

Background Docosahexaenoic acid (DHA) is an abundant

fatty acid in the brain. In the diet, DHA is found

mostly in fatty fish. The content of DHA has been

shown to be decreased in the brain and plasma of

patients with dementia.

Objective To determine whether plasma

phosphatidylcholine (PC) DHA content is associated

with the risk of developing dementia.

Design, Setting, and Participants A prospective

follow-up study in 899 men and women who were free of

dementia at baseline, had a median age of 76.0 years,

and were followed up for a mean of 9.1 years for the

development of all-cause dementia and Alzheimer

disease.

Main Outcome Measures Plasma PC fatty acid levels

were measured at baseline. proportional regression

analysis was used to assess relative risks of

all-cause dementia and Alzheimer disease according to

baseline plasma levels.

Results Ninety-nine new cases of dementia (including

71 of Alzheimer disease) occurred during the

follow-up. After adjustment for age, sex,

apolipoprotein E 4 allele, plasma homocysteine

concentration, and education level, subjects in the

upper quartile of baseline plasma PC DHA levels,

compared with subjects in the lower 3 quartiles, had a

relative risk of 0.53 of developing all-cause dementia

(95% confidence interval, 0.29-0.97; P=.04) and 0.61

of developing Alzheimer disease (95% confidence

interval, 0.31-1.18; P=.14). Subjects in the upper

quartile of plasma PC DHA levels had a mean DHA intake

of 0.18 g/d and a mean fish intake of 3.0 servings per

week (P<.001) in a subset of 488 participants. We

found no other significant associations.

Conclusion The top quartile of plasma PC DHA level

was associated with a significant 47% reduction in the

risk of developing all-cause dementia in the

Framingham Heart Study.