New research suggests eating baked or broiled fish once a week can make the brain healthier, regardless of omega-3 fatty acid levels.
The study, published in the American Journal of Preventive Medicine, further show the effect lifestyle factors have on brain health later in life, the University of Pittsburgh reported.
Past research has suggested lifestyle changes such as reduction in the rate of physical inactivity, obesity, and smoking, have a significant influence over dementia risk. Omege-3 fatty acids have an antioxidant effect believed to also improve brain health down the road.
"Our study shows that people who ate a diet that included baked or broiled, but not fried, fish have larger brain volumes in regions associated with memory and cognition," said senior investigator James T. Becker, Ph.D., professor of psychiatry, Pitt School of Medicine. "We did not find a relationship between omega-3 levels and these brain changes, which surprised us a little. It led us to conclude that we were tapping into a more general set of lifestyle factors that were affecting brain health of which diet is just one part."
To make their findings the researchers analyzed data from 260 participants who provided information on their dietary intake, were "cognitively normal" at two points during the study period, and had hogh resolution brain MRI scans.
"The subset of CHS participants answered questionnaires about their eating habits, such as how much fish did they eat and how was it prepared," lead investigator Cyrus Raji, M.D., Ph.D. said. "Baked or broiled fish contains higher levels of omega-3s than fried fish because the fatty acids are destroyed in the high heat of frying, so we took that into consideration when we examined their brain scans."
The team found patients who ate baked or broiled fish a minimum of once a week had a larger gray matter brain volume in the areas responsible for memory and cognition. These individuals were more likely to have a college education than those who ate less fish. The researchers did not find a link between omega-3 fatty acid levels and a healthier brain.
"This suggests that lifestyle factors, in this case eating fish, rather than biological factors contribute to structural changes in the brain," Dr. Becker noted. "A confluence of lifestyle factors likely are responsible for better brain health, and this reserve might prevent or delay cognitive problems that can develop later in life."
