A diet rich in omega-3 fatty acids appears to have a positive effect on brain health in older women who live in areas with high levels of air pollution. Namely, older women who eat more than one to two servings a week of baked or broiled fish or shellfish may consume enough omega-3 fatty acids to counteract the effects of air pollution on the brain, according to a new study published in the July 15, 2020 edition of Neurology journal.
“Fish are an excellent source of omega-3 fatty acids and easy to add to the diet,” said study author Ka Kahe, M.D., Sc.D., of Columbia University in New York. “Omega-3 fatty acids have been shown to fight inflammation and maintain brain structure in aging brains. They have also 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.”
“Our findings suggest that 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 toxic effects of air pollution”
What the findings suggest
The study involved 1,315 women with an average age of 70 who did not have dementia at the start of the study. The women completed questionnaires about diet, physical activity, and medical history. Participants were also given blood tests and researchers measured the amount of omega-3 fatty acids in their red blood cells and then divided the women into four groups based on the amount of omega-3 fatty acids in their blood.
Researchers used the women’s home addresses to determine their three-year average exposure to air pollution. Participants then had MRI brain scans to measure various areas of the brain including white matter, which is composed of nerve fibers that send signals throughout the brain, and the hippocampus, the part of the brain associated with memory.
After adjusting for age, education, smoking and other factors that could affect brain shrinkage, researchers found that women who had the highest levels of omega-3 fatty acids in the blood had greater volumes of white matter than those with the lowest levels. Women with the highest levels of omega-3 fatty acids in the blood also had greater volumes of the hippocampus.
In contrast, women with lower levels of omega-3 fatty acids in their blood had more brain shrinkage, specifically in the hippocampus than women with higher levels of omega-3.
“Our findings suggest that 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 toxic effects of air pollution,” explains Dr Kahe.