Consuming fish once weekly increases memory and cognition
There are at least 5 million Americans with age-related dementia. These numbers will continue to rise in the aging of the US population. It has been estimated that by 2040, 80 million people will have dementia. Some studies have indicated that up to half of the Alzheimer’s cases could be prevented through lifestyle changes. The anti-oxidant effect of omega-3 fatty acids, which are found in high amounts in fish, seeds and nuts, and certain oils is associated with a lower risk of cognitive decline and dementia.
Dr. Cyrus Raji, MD, PhD, Department of Radiology, University of California, Los Angeles Medical Center and lead investigator along with colleagues set out to determine whether dietary fish consumption is related to brain structural integrity among cognitively normal elders.
For the study researchers examined data from 260 cognitively normal individuals from the Cardiovascular Health Study in which participants who filled out a Food Frequency Questionnaire from the National Cancer Institute which include questions concerning fish consumption and fish preparation. Participants also underwent brain MRI. Information on fish consumption was collected between1989 to 1990 and MRI obtained between 1998 and 1999.
According to Dr. Raji, "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."
Weekly consumption of baked or broiled fish had greater grey matter brain volumes in areas of the brain responsible for memory (4.3 percent) and cognition (14 percent). Participants who consumed fish weekly were also more likely to have a college education in comparison tot those who did not consume fish on a regular basis. These results did not change when including omega-3 fatty acid estimates in the analysis.
Dr. James T. Becker, PhD, professor of Psychiatry, Psychology, and Neurology at the Pitt School of Medicine and senior investigator commented "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.” "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."
This study is published in the American Journal of Preventive Medicine.