Eating oily fish may help stave off mental decline, say scientists

DIETS lacking an essential nutrient found in oily fish may hasten brain shrinkage and mental decline, a study has found.

Brain scans carried out on 1,575 people, average age 67, showed a greater rate of brain shrinkage in those who lacked docosahexaenoic acid (DHA).

DHA is an omega-3 fatty acid that is thought to help nerve cells communicate with each other. The richest source of the nutrient is oily fish, such as herring, mackerel and sardines.

Dr Zaldy Tan, from the University of California at Los Angeles, who led the US research reported in the journal Neurology, said: “People with lower blood levels of omega-3 fatty acids had lower brain volumes that were equivalent to about two years of structural brain ageing.”

However, Dr Marie Janson, from the charity Alzheimer’s Research UK, said more work was needed, adding: “People shouldn’t fill their freezers with oily fish just yet.”