Researchers at Martek Biosciences Corporation, in Columbia, Maryland, studied the effects of docosahexaenoic acid (DHA) (an essential fatty acid) on improving cognitive functions in healthy older adults with age-related cognitive decline.

First, the details.

• 485 healthy adults had a Mini-Mental State Examination score greater than 26 and a Logical Memory (Wechsler Memory Scale III) baseline score at least 1 standard deviation below younger adults.
  • In other words, they had subjective memory complaints and mild memory deficit, but no dementia.
  • A Mini-Mental State Examination score below 20 usually indicates cognitive (reasoning) impairment.
  • Wechsler Memory Scale III is designed to assess learning, memory, and working memory.
• They were randomly assigned to a treatment group for 24 weeks.
  • 900 mg/day of DHA taken by mouth
  • Matching placebo
• The researchers looked for changes in the CANTAB Paired Associate Learning (PAL), which assesses visual memory and new learning.
• Neither the patients nor researchers knew the treatment given — double blind.

And, the results.

• Participants taking DHA supplements made significantly fewer errors in visual memory and new learning, but there was no difference between groups.
• DHA supplementation was also associated with significantly improved immediate and delayed verbal recognition memory scores, but not working memory or executive function tests.

The bottom line?

The authors concluded, “24-week supplementation with 900 mg/d DHA improved learning and memory function in ARCD and is a beneficial supplement that supports cognitive health with aging.”

It’s modest improvement, and supports the conclusions in an earlier review of 15 studies. “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 Alzheimer’s disease).”

11/27/10 16:50 JR