Researchers have found that a diet high in omega-3 fatty acids may prevent neurodegeneration among older women living in areas with high air pollution.
For the study, the researchers asked 1,315 women with an average age of 70 to fill in questionnaires about their diet, physical activity levels, and medical history. None of the women had dementia at the beginning of the study.
Participants in the study were also given blood tests to measure the amount of omega-3 fatty acids in their red blood cells. Brain scans with magnetic resonance imaging (MRI) were also conducted to measure the various areas in the brain, like the hippocampus, associated with memory, and levels of white matter, nerve fibers that send signals throughout the brain. The researchers then used the participants' addresses to determine their three-year average exposure to air pollution.
In the end, the researchers found that women who had the highest levels of omega-3 fatty acids in their blood also had greater volumes of white matter. The researchers found that the more air pollution the women were exposed to, the less white matter they had. Meanwhile, they also found a correlation between higher their levels of omega-3 fatty acids in their blood and larger hippocampi.
"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 potentially toxic effects of air pollution," says Ka He, one of the study's authors.
"It's important to note that our study only found an association between brain volume and eating fish. It does not prove that eating fish preserves brain volume. And since separate studies have found some species of fish may contain environmental toxins, it's important to talk to a doctor about what types of fish to eat before adding more fish to your diet."
Although taken from a reasonable sample size, as most participants were older white women, it is impossible to generalize the findings for other demographic groups- both in age and ethnicity.