367: No benefits of omega-3 fatty acid on cognitive function in older people

November 02, 2012

PEARLS 367, September 2012, written by Brian R McAvoy

Clinical question: How effective is omega-3 long chain polyunsaturated fatty acid (PUFA) supplementation for the prevention of dementia and cognitive decline in cognitively healthy older people?

Bottom line: There was no benefit to cognitive function (measured by mini-mental state examination, word learning, digit span and fluency) from omega-3 PUFA supplementation taken for 6 to 40 months in cognitively healthy people over 60 years old. Supplementation was generally well tolerated. The most commonly reported side effects were mild gastrointestinal problems. All 3 studies were of high quality.

Caveat: None of the studies examined the effect of omega-3 PUFA on incident dementia. Longer-term studies may identify changes in cognitive function. Omega-3 PUFA supplements may have other health benefits.

Context: Evidence from observational studies has suggested that diets high in omega-3 PUFA may protect people from cognitive decline and dementia. Oily fish, such as salmon, mackerel, herring and sardines, are a rich source of omega-3 PUFAs, which are essential for brain development.

Cochrane Systematic Review: Sydenham E et al. Omega-3 fatty acid for prevention of cognitive decline and dementia. Cochrane Reviews, 2012, Issue 6. Article No. CD005379. DOI: 10.1002/14651858.CD005379.pub3. This review contains 3 studies involving 3536 participants.

Pearls are an independent product of the Cochrane primary care group and are meant for educational use and not to guide clinical care.