Fish Oil Supplements: No Effect on Cognitive Decline in Seniors


Some research has suggested that taking an omega-3 fatty acid (fish oil) supplement can help protect brain health when coupled with a healthful diet and exercise. But a large three-year randomized clinical trial found that a supplement, alone or combined with multiple lifestyle interventions (nutritional advice, physical activity, cognitive training, and yearly consultations), is no more effective in slowing cognitive decline than placebo. The findings were published last year in Lancet Neurology.

The 1,680 trial participants (two-thirds were women) were at least 70 years old. All had normal cognition and one of the following risk factors for cognitive decline:

  • a memory complaint,
  • limitations in one activity of daily living, or
  • a slow gait.

Participants were randomly assigned to one of the following groups:

  • multiple lifestyle interventions,
  • multiple lifestyle interventions plus an omega-3 fatty acid supplement twice daily,
  • the omega-3 fatty acid supplement alone, or
  • placebo.

Standardized tests administered at the end of the study showed little difference in cognitive decline among the four groups.

Earlier trials suggested that various interventions can protect against cognitive impairment, so investigators are likely to continue their efforts to identify an effective strategy. In the meantime, experts advise eating omega-3-rich foods, such as salmon, mackerel, and lake trout, at least twice a week and regularly exercising your body-and your brain.