Elderly people who eat fish at least once a week lower their risk of developing dementia including Alzheimer's disease, according to a report published in the British Medical Journal.

French researchers tested whether there was a link between eating fish or seafood, which contains polyunsaturated fatty acids, or meat, which contains saturated fatty acids, and the risk of dementia.

A total of 1,674 people, age 68 and older, without dementia and living at home were included in the study. Their frequency of eating meat and fish or seafood was recorded as daily, at least once a week (but not every day), from time to time (but not every week), or never. The participants were followed up at two, five and seven years after the start of the study.

Participants who ate fish or seafood at least once a week had a significantly lower risk of developing dementia after seven years. No significant link was found between eating meat and the risk of dementia.

The authors speculate that fatty acids contained in fish oils could reduce inflammation in the brain and have a specific role in the brain's development and regeneration of nerve cells.

Other sources: British Medical Journal