Omega-3 supplements do not appear to prevent mental decline in old age, a new study shows.
Previous research has suggested that omega-3 fatty acids, especially those in fish oil, can help keep brain cells healthy.
But experts now say there is no evidence that they maintain mental function in ageing individuals, at least over timescales of up to three years.
Researchers studied the findings of three trials looking at the effects of omega-3 taken in the form of capsules or added to margarine spread.
In each case, their benefits were compared with 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. None had any initial signs of mental decline or dementia.
Participants taking omega-3 scored no better in memory and mental tests than those not given the supplements.