09.01.12
Nutraceutical: Omega 3s
Indication: Cognitive decline
Source: Database Syst Rev, Jun 13, 2012; 6:CD005379.
Research: The objective of this study was to assess the effects of omega 3 PUFA supplementation for the prevention of dementia and cognitive decline in cognitively healthy older people. Researchers searched ALOIS—the Cochrane Dementia and Cognitive Improvement Group's Specialized Register—on April 6, 2012 using the terms: omega 3, PUFA, fatty acids, fatty acid, fish, linseed, eicosapentaenoic and docosahexaenoic. The selection criteria included randomized controlled trials of an omega 3 PUFA intervention provided for a minimum of 6 months to participants aged 60 years and over who were free from dementia or cognitive impairment at the beginning of the study. Information on cognitive function at the start of a study was available on 4080 participants randomized in three trials. Cognitive function data were available on 3536 participants at the final follow-up. In two studies participants received gel capsules containing either omega 3 PUFA (the intervention) or olive or sunflower oil (placebo) for 6 or 24 months. In one study, participants received margarine spread for 40 months; the margarine for the intervention group contained omega 3 PUFA. Two studies had cognitive health as their primary outcome; one study of cardiovascular disease included cognitive health as an additional outcome.
Results: In two studies involving 1043 participants, tests of cognitive function, such as word learning, digit span and verbal fluency showed no beneficial effect of omega 3 PUFA supplementation. Participants in both the intervention and control groups experienced either small or no cognitive declines during the studies. Researchers believe direct evidence on the effect of omega 3 PUFA on incident dementia is lacking and further studies of longer duration are required. Longer-term studies, they concluded, might identify greater change in cognitive function in study participants and thereby enhance the ability to detect the possible effects of omega 3 PUFA supplementation in preventing cognitive decline in older people.