Old people who eat fish or seafood at least once a week have a reduced risk of dementia. Researchers from the University of Texas studied a group of 1205 people aged over 65 and without dementia at the beginning. They asked them about the frequency of consuming meat, fish and seafood, then followed them up to, five and seven years afterwards.
Those who ate fish or seafood at least once a week had a significantly lower risk of being diagnosed with dementia in the seven years following. Education could partly account for this, however (highly educated people being more likely to be regular fish eaters).
The researchers think that the fatty acids in fish oil reduce inflammation in the brain and also protect the brain's circulation. The 'old wives' tale that fish is good for the brain appears to have more than a grain of truth in it. The research is still on and has to surveyed in detail.