Alzheimer's DementiaOmega-3 Fatty Acids

Reviewing the effect of omega-3 on dementia

In seniors there’s a difference between the role of omega-3 fatty acids to slow cognitive decline vs preventing or treating dementia, according to researchers at Johns Hopkins School of Medicine in Baltimore, Maryland.

First, the details.

  • A search of the literature identified 15 studies of eating fish or taking omega-3 supplements.
  • Outcomes were either the risk of cognitive (reasoning) decline or the diagnosis of Alzheimer’s disease (AD).

And, the results.

  • Observational studies that used cognitive decline as an outcome reported significant benefits.
  • But only 4 of 8 observational studies that used incidence of AD or dementia as an outcome reported positive findings.
  • None of 4 small clinical trials provided convincing evidence.

The bottom line?
The authors concluded, “The existing data favor a role for long-chain omega-3 fatty acids in slowing cognitive decline in elderly individuals without dementia, but not for the prevention or treatment of dementia (including AD).”

It’s possible that these findings are heavily influenced by study design, dosages, the ratio of long-chain omega-3 to omega-6 fatty acids, or the choice of outcome measurements.

In other words, these are preliminary findings, and more research is needed to know for sure.

3/6/09 20:28 JR

Hi, I’m JR

John Russo, Jr., PharmD, is president of The MedCom Resource, Inc. Previously, he was senior vice president of medical communications at, a complementary and alternative medicine website.