Older women who eat one to two servings of fish or shellfish a week may consume enough omega-3 foods. Thus, they could counteract the effects of air pollution on the brain. This is the result of a new study. The researchers found that older women who lived in areas with high air pollution, those who had the lowest levels of omega-3s in their blood had more brain shrinkage than women with the highest concentrations.
Brain protection through omega 3 foods
Fish is an excellent source of omega-3 fatty acids and is easy to include in the diet. Previous study results also show that omega-3 fatty acids fight inflammation and maintain brain structure in aging brains. Because of this, researchers have found that they reduce brain damage caused by neurotoxins like lead and mercury. The authors of the study therefore investigated whether fatty acids from omega 3 foods could have a protective effect against fine dust particles in air pollution. The study included 1315 women with an average age of 70 years. At the start of the study, the subjects did not have dementia. The women also completed questionnaires on diet, physical activity, and medical history.
Researchers used the nutrition questionnaire to calculate the average amount of fish each woman consumed per week, including grilled or baked fish, canned food, tuna salad, and un-fried shellfish. Fried fish was not included because research has shown that frying damages omega-3 fatty acids. The participants received blood tests. The researchers measured the amount of omega-3 fatty acids in their red blood cells and divided the women into four groups based on the amount of omega-3 fatty acids in their blood. The team used the women’s residential addresses to determine their average three-year exposure to air pollution. Participants then underwent magnetic resonance imaging (MRI) brain scans. Thus, the volume of the white matter, which consists of nerve fibers, could be measured. These fibers send the signals throughout the brain. Also included is the hippocampus, the part of the brain that is connected to memory.
After adjusting for age, education, smoking, and other factors that could affect brain shrinkage, the researchers found that women with the highest levels of omega-3 fatty acids in their blood had more white matter. Those had 410 cubic centimeters of white matter compared to 403 cubic centimeters for the low-fatty acid group. The researchers found that for every quarter increase in air pollution, the average volume of white matter decreased by 11.52 cm3 in people with lower omega-3 levels and 0.12 cm3 in those with higher levels was. Women with the highest levels of omega-3 fatty acids in their blood also had larger amounts of the hippocampus.
Since separate studies have shown that some types of fish may contain environmental toxins, it is important to speak with a doctor about types of fish before adding more fish to your diet. One limitation of the study was that most of the participants were older white women. The results cannot therefore be transferred to other people. In addition, the researchers could the study examine exposure to later air pollution only, not early or intermediate life exposure. Future studies should therefore look at exposure to air pollution over a person’s lifespan.