Why oily fish helps protect brain against air pollution

EATING oily fish protects the brain against the toxic damage of air pollution, according to research.

And it could even reduce the risk of Alzheimer’s disease and other forms of dementia.

US scientists found that older women who ate at least three servings of baked or grilled seafood – like salmon, sardines and mackerel – a week counteracted the damaging effects of smog on grey matter.

Dr Ka Kahe, of Columbia University in New York was the study’s lead author.

He said: “Omega-3 fatty acids have been found to reduce brain damage caused by neurotoxins like lead and mercury.

“So we explored if omega-3 fatty acids have a protective effect against another neurotoxin – the fine particulate matter found in air pollution.” Once controversial, evidence is mounting that dirty air damages the brain.

High levels have been linked to poor cognitive abilities in children.

They have also been found to increase adults’ risk of cognitive decline – and possibly even contribute to depression.

The latest findings are based on 1,315 women with an average age of 70 who did not suffer from dementia. They completed questionnaires about diet, physical activity and medical history.

The average weekly amount of fish each individual consumed was calculated – though fried fish was not included because deep frying damages omega-3 fatty acids.

Blood tests measured the amount of omega-3 fatty acids in their red cells. The women were then divided into four groups based on their omega-3 fatty acids. Home addresses were used to work out their three-year average exposure to air pollution.

Participants then underwent MRI scans to measure various areas of the brain.

Dr Kahe said: “Our findings suggest higher levels of omega-3 fatty acids in the blood from fish consumption may preserve brain volume as women age and possibly protect against the potential effects of air pollution.”

He said the study “only found an association between brain volume and eating fish”. It does not prove eating fish preserves brain volume.

He added: “And since separate studies have found some species of fish may contain environmental toxins, it’s important to talk to a doctor about what fish to eat before adding more of it to your diet.” toxic