Although fish oils containing DHA may help to prevent age-related vision loss, the supplement is not effective at preventing the cognitive decline that is a hallmark of dementia, says a study published in the June 2012 issue of Cochrane Database of Systematic Reviews.
Researchers from the London School of Hygiene & Tropical Medicine in London, UK wanted to assess the effectiveness of the omega-3 fatty acids found in fish oil supplements at preventing declines in cognition as people age. Previous observational studies have noted that diets high in omega-3s from natural food sources such as cold water fish and certain plant oils may protect against cognitive decline and dementia. The researchers wanted to know if the same were true for omega-3 supplements.
To determine the effects, if any, of fish oil supplements on cognitive decline, the researchers analyzed data on over 3,500 participants in three randomized controlled trials. All of the participants in the studies were at least sixty years old and did not show any signs of cognitive decline or dementia at the time that they enrolled in the study. In each study, one group was given omega-3 supplements while the other group was given a placebo.
When their cognitive status was assessed at the ends of the studies, the participants in the groups given the omega-3 supplements performed no better at “mini-mental state exams” than the participants who have been given placebos. In other words, fish oil supplements containing omega-3 fatty acids do not appear to benefit individuals in terms of preventing cognitive decline.
However, as the researchers noted, these three studies were all short-term studies and that longer-term studies need to be conducted to determine if omega-3 supplements are beneficial in the long run.
Even though fish oil supplements do not appear to be effective in preventing cognitive decline short-term, it is still recommended that individuals eat a diet containing fish because of the other health benefits of omega-3s.
Do you take fish oil supplements for your health?