Plasma phosphatidylcholine docosahexaenoic acid content and risk of dementia and Alzheimer disease: the Framingham Heart Study.
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.


METHODS
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.


METHODS
Plasma PC fatty acid levels were measured at baseline. Cox 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 epsilon4 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.


CONCLUSIONS
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.
Schaefer
Ernst J
EJ
Lipid Metabolism Laboratory, Jean Mayer US Department of Agriculture Human Nutrition REsearch Center on Aging, Tuffs University, Boston, MA 02111, USA. ernst.schaefer@tufts.edu
Bongard
Vanina
V
Beiser
Alexa S
AS
Lamon-Fava
Stefania
S
Robins
Sander J
SJ
Au
Rhoda
R
Tucker
Katherine L
KL
Kyle
David J
DJ
Wilson
Peter W F
PW
Wolf
Philip A
PA
D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000178:diet therapy / Q000453:epidemiology; D003704:Dementia / Q000097:blood / Q000178:diet therapy / Q000453:epidemiology; D004281:Docosahexaenoic Acids / Q000097:blood / Q000627:therapeutic use*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008609:Mental Status Schedule; D010713:Phosphatidylcholines / Q000097:blood*; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012306:Risk
D010713:Phosphatidylcholines; D004281:Docosahexaenoic Acids