title: Plasma phosphatidylcholine docosahexaenoic acid content and risk of dementia and Alzheimer disease: the Framingham Heart Study.
abstract: 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.
authors.affiliation: 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
authors.forename: Ernst J
authors.initials: EJ
authors.lastname: Schaefer
authors.forename: Vanina
authors.initials: V
authors.lastname: Bongard
authors.forename: Alexa S
authors.initials: AS
authors.lastname: Beiser
authors.forename: Stefania
authors.initials: S
authors.lastname: Lamon-Fava
authors.forename: Sander J
authors.initials: SJ
authors.lastname: Robins
authors.forename: Rhoda
authors.initials: R
authors.lastname: Au
authors.forename: Katherine L
authors.initials: KL
authors.lastname: Tucker
authors.forename: David J
authors.initials: DJ
authors.lastname: Kyle
authors.forename: Peter W F
authors.initials: PW
authors.lastname: Wilson
authors.forename: Philip A
authors.initials: PA
authors.lastname: Wolf
mesh_terms: 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
chemical_list: D010713:Phosphatidylcholines; D004281:Docosahexaenoic Acids