Fish consumption and omega-3 fatty acid supplementation for prevention or treatment of cognitive decline, dementia or Alzheimer's disease in older adults - any news?

Curr Opin Clin Nutr Metab Care. 2017 Mar;20(2):104-109. doi: 10.1097/MCO.0000000000000350.


Purpose of review: Twenty years of research indicates that fish and n-3 fatty acids (FAs), for example docosahexaenoic acid, may attenuate cognitive decline including Alzheimer's disease in older people. This review concerns reports during 2015-2016 in humans.

Recent findings: One prospective cohort study showed that seafood consumption was related to less neuritic plaques and neurofibrillary tangles in brain autopsies from elderly care residents. In a large 5-year intervention no effects on cognition could be shown either in n-3 FA supplemented or in control patients. Two meta-analyses in community-dwelling patients support preservation of cognition with higher fish intake. Older adults with memory complaints may improve cortical blood flow during memory challenges by n-3 FA supplementation. Recalculations from a report in Alzheimer's disease patients indicated a dose-response pattern between increments of serum n-3 FAs and cognitive improvement. Still, a Cochrane review (using three randomized control trials) concluded that n-3 FAs cannot provide any 6-month benefit in patients with mild/moderate Alzheimer's disease.

Summary: The accumulated knowledge indicates that healthy populations may have preventive benefits from fish and docosahexaenoic acid intake, like older adults with memory complaints/mild cognitive impairment, and maybe subgroups of patients with mild/moderate Alzheimer's disease may also show such benefits. Still, more studies are needed.

Publication types

  • Review

MeSH terms

  • Aged
  • Alzheimer Disease / prevention & control*
  • Alzheimer Disease / therapy
  • Animals
  • Cognitive Dysfunction / prevention & control*
  • Cognitive Dysfunction / therapy
  • Dementia / prevention & control*
  • Dementia / therapy
  • Dietary Supplements*
  • Docosahexaenoic Acids / therapeutic use
  • Eating
  • Fatty Acids, Omega-3 / therapeutic use*
  • Fishes*
  • Humans
  • Middle Aged


  • Fatty Acids, Omega-3
  • Docosahexaenoic Acids