Do fish oils REALLY keep the brain young?

Fish oil supplements are taken by millions of people to keep their wits sharp as they age. But doubts have emerged as to whether the capsules actually do anything to slow mental decline.
A study of 4,000 people found no evidence omega-3 supplements helps people maintain their brain power. Scientists tracked the patients for five years, finding that the whole group declined at roughly the same rate, no matter whether they had taken the supplements.

Previous studies have associated regular fish consumption with lower rates of dementia and larger brain volumes.  It is also linked to better heart health, stronger bones and lower risk of eye conditions.
It has been widely assumed that omega-3 fatty acids were behind the dietary benefits of fish. They are highly concentrated in the brain and appear to be important for the growth and repair of nerves.
But the research, by Harvard Medical School and the National Institutes of Health in Bethesda, Maryland, suggests that fish oil supplements on their own are not enough to keep the brain young.

Source  - Daily Mail