Role of omega-3 in preventing cognitive decline in older people questioned

June 12, 2012

Older people who take omega-3 fish oil supplements are probably not reducing their chances of losing cognitive function, according to a new Cochrane systematic review. Based on the available data from studies lasting up to 3.5 years, the researchers concluded that the supplements offered no benefits for cognitive health over placebo capsules or margarines, but that longer term effects are worth investigating.

Omega-3 fatty acids are fats responsible for many important jobs in the body. We get these fats through our daily diets and the three major omega-3 fats are: alpha linolenic acid (ALA) from sources such as nuts and seeds and eicosapentoic acid (EPA) and docosahexaenoic acid (DHA) from sources including oily fish such as salmon and mackerel. A number of studies have hinted that omega-3 fatty acids and in particular may be involved in keeping in the brain healthy into old age. However, there is limited evidence for the role of these fats in preventing cognitive decline and dementia.

The researchers, led by Emma Sydenham at the London School of Hygiene & Tropical Medicine (LSHTM), London, UK, gathered together evidence from three high quality trials comparing the effects of omega-3 fatty acids taken in capsules or margarine spread to those of sunflower oil, olive oil or regular margarine. A total of 3,536 people over the age of 60 took part in the trials, which lasted between six and 40 months. None of the participants had any signs of poor cognitive health or dementia at the start of the trials.

The researchers found no benefit of taking the omega-3 capsules or spread over placebo capsules or spread. Participants given omega-3 did not score better in standard mental state examinations or in memory and verbal fluency tests than those given placebo.

"From these studies, there doesn't appear to be any benefit for for older people of taking omega-3 supplements," said Alan Dangour, a nutritionist at LSHTM and co-author of the report. "However, these were relatively short-term studies, so we saw very little deterioration in cognitive function in either the intervention groups or the control groups. It may take much longer to see any effect of these supplements."

The researchers conclude that the longer term effects of omega-3 fatty acids on and dementia need to be explored in further studies, particularly in people with low intakes of omega-3 fatty acids in their diet. In the meantime, they stress other potential health benefits. "Fish is an important part of a healthy diet and we would still support the recommendation to eat two portions a week, including one portion of ," said Dangour.

Explore further: Low levels of omega-3 fatty acids may cause memory problems

More information: Sydenham E, Dangour AD, Lim WS. Omega 3 fatty acid for the prevention of cognitive decline and dementia. Cochrane Database of Systematic Reviews 2012, Issue 6. Art. No.: CD005379. DOI: 10.1002/14651858.CD005379.pub3

Related Stories

Low levels of omega-3 fatty acids may cause memory problems

February 27, 2012
A diet lacking in omega-3 fatty acids, nutrients commonly found in fish, may cause your brain to age faster and lose some of its memory and thinking abilities, according to a study published in the February 28, 2012, print ...

Omega-3 supplements no help against repeat heart trouble: review

April 9, 2012
(HealthDay) -- Taking omega-3 fatty acid supplements won't protect against repeat heart attacks, strokes or other cardiovascular problems, a new analysis indicates.

Fish oil supplements boost mental performance: study

October 25, 2011
(Medical Xpress) -- A particular fish oil supplement has been shown to improve blood flow to the brain during mental activity and helped to reduce mental fatigue in young adults, according to research from Northumbria University. 

Recommended for you

Parents have critical role in preventing teen drinking

July 20, 2017
Fewer teenagers are drinking alcohol but more needs to be done to curb the drinking habits of Australian school students, based on the findings of the latest study by Adelaide researchers.

Aging Americans enjoy longer life, better health when avoiding three risky behaviors

July 20, 2017
We've heard it before from our doctors and other health experts: Keep your weight down, don't smoke and cut back on the alcohol if you want to live longer.

Fresh fish oil lowers diabetes risk in rat offspring

July 19, 2017
Fresh fish oil given to overweight pregnant rats prevented their offspring from developing a major diabetes risk factor, Auckland researchers have found.

High-dose vitamin D doesn't appear to reduce the winter sniffles for children

July 18, 2017
Giving children high doses of vitamin D doesn't appear to reduce the winter sniffles, a new study has found.

Scientists develop new supplement that can repair, rejuvenate muscles in older adults

July 18, 2017
Whey protein supplements aren't just for gym buffs according to new research from McMaster university. When taken on a regular basis, a combination of these and other ingredients in a ready-to-drink formula have been found ...

Study: Eating at 'wrong time' affects body weight, circadian rhythms

July 18, 2017
A new high-precision feeding system for lab mice reinforces the idea that the time of day food is eaten is more critical to weight loss than the amount of calories ingested.

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.