title: Associations between Serum Omega-3 Fatty Acid Levels and Cognitive Functions among Community-Dwelling Octogenarians in Okinawa, Japan: The KOCOA Study.
abstract: BACKGROUND
  Epidemiological studies have found frequent consumption of fatty fish is protective against cognitive decline. However, the association between circulating omega-3 polyunsaturated fatty acid (PUFA) levels and cognitive functions among the oldest old is not well known.
  
  
  OBJECTIVE
  To examine the association between serum PUFA levels and cognitive function among community-dwelling, non-demented elderly aged over 80 years old.
  
  
  METHODS
  The data came from the Keys to Optimal Cognitive Aging (KOCOA) study; an ongoing cohort of relatively healthy volunteers aged over 80 years old, living in Okinawa, Japan. One hundred eighty five participants (mean age 84.1±3.4 years) assessed in 2011 who were free from frank dementia (defined as Clinical Dementia Rating <1.0) were used for the current cross-sectional study. We examined whether serum omega-3 PUFAs (docosahexaenoic acid [DHA] and eicosapentaenoic acid [EPA]), arachidonic acid (AA), EPA/AA ratio, DHA/AA ratio, and DHA+EPA are associated with (1) age and (2) global cognitive function (Japanese MMSE) and executive function (Verbal Fluency Letter). Data was analyzed univariately by t-test and multivariately by cumulative logistic regression models controlling for age, gender, years of education, obesity, hypertension, diabetes, and dyslipidemia.
  
  
  RESULTS
  Serum DHA levels decreased with increasing age (p = 0.04). Higher global cognitive function was associated with higher levels of serum EPA (p = 0.03) and DHA + EPA (p = 0.03) after controlling for confounders.
  
  
  CONCLUSIONS
  Higher serum EPA and DHA + EPA levels were independently associated with better scores on global cognitive function among the oldest old, free from dementia. Longitudinal follow-up studies are warranted.
authors.affiliation: Department of Cardiovascular Medicine, Nephrology and Neurology, University of the Ryukyus, Okinawa, Japan.
authors.forename: Junko
authors.initials: J
authors.lastname: Nishihira
authors.affiliation: Department of Cardiovascular Medicine, Nephrology and Neurology, University of the Ryukyus, Okinawa, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Tokashiki
authors.affiliation: Clinical Laboratories, University of the Ryukyus Hospital, Okinawa, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Higashiuesato
authors.affiliation: Department of Human Welfare, Okinawa International University, Okinawa, Japan.|Department of Geriatric Medicine, John A. Burns School of Medicine, University of Hawaii, Honolulu, USA.
authors.forename: Donald Craig
authors.initials: DC
authors.lastname: Willcox
authors.affiliation: Department of Neurology and Layton Aging & Alzheimer's Disease Center, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Nora
authors.initials: N
authors.lastname: Mattek
authors.affiliation: Department of Neurology and Layton Aging & Alzheimer's Disease Center, Oregon Health & Science University, Portland, OR, USA.
authors.forename: Lynne
authors.initials: L
authors.lastname: Shinto
authors.affiliation: Department of Cardiovascular Medicine, Nephrology and Neurology, University of the Ryukyus, Okinawa, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Ohya
authors.affiliation: Department of Neurology and Layton Aging & Alzheimer's Disease Center, Oregon Health & Science University, Portland, OR, USA.|Department of Neurology and Michigan Alzheimer's Disease Center, University of Michigan, Ann Arbor, MI, USA.
authors.forename: Hiroko H
authors.initials: HH
authors.lastname: Dodge
mesh_terms: D000367:Age Factors; D000369:Aged, 80 and over; D016718:Arachidonic Acid / Q000097:blood; D001774:Blood Chemical Analysis; D003071:Cognition / Q000502:physiology*; D003430:Cross-Sectional Studies; D004522:Educational Status; D015525:Fatty Acids, Omega-3 / Q000097:blood*; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008609:Mental Status Schedule; D009765:Obesity / Q000097:blood / Q000453:epidemiology / Q000523:psychology; D011446:Prospective Studies; D012737:Sex Factors
chemical_list: D015525:Fatty Acids, Omega-3; D016718:Arachidonic Acid
keywords: Cognitive function; DHA; EPA; KOCOA; Okinawa; PUFA; non-demented subjects; oldest old