Eating broiled or baked fish every week could ward off dementia later in life, according to the recent study.
The research was conducted by investigators at the University of Pittsburgh School of Medicine in Pennsylvania, who note that their study adds to increasing evidence that lifestyle factors could add to brain health later in life, perhaps even reducing risk of dementia.
According to senior researcher Prof. James T. Becker, health professionals estimate that more than 80 million people will have dementia by 2040. And the Alzheimer's Association note that 5.2 million Americans currently have Alzheimer's disease, one of the most common types of dementia.
By 2050, the organization estimates that the number of people aged 65 and older with Alzheimer's disease could nearly triple to 16 million if some sort of medical breakthrough or intervention is not put in place to slow or stop the disease.
Previous studies have suggested that omega-3 fatty acids - found in fish, seeds, nuts and certain oils - have an anti-oxidant effect that is linked to improved brain health.
But to further investigate the link between dietary intake and brain health, the researchers analyzed data from 260 cognitively normal participants from the Cardiovascular Health Study (CHS). These participants provided dietary intake information and underwent high-resolution brain magnetic resonance imaging (MRI) scans.
In total, the CHS was a 10-year, multi-center study that began in 1989 to investigate heart disease risk factors for individuals over 65.
Weekly fish eaters had more grey matter in memory and cognition brain areas
Explaining the methods of data collection, lead investigator Dr. Cyrus Raji, currently at the University of California-Los Angeles, says:
"The subset of CHS participants answered questionnaires about their eating habits, such as how much fish did they eat and how was it prepared."
He explains that broiled or baked fish has higher omega-3 levels 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 that participants who ate baked or broiled fish at least once each week had larger grey matter brain volumes in regions of the brain responsible for memory and cognition. Interestingly, they were also more likely to have a college education than those who did not regularly eat fish.
However, Dr. Becker explains that they did not find a link between the brain differences and omega-3 blood levels:
"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."
He adds that their findings led them to conclude that they were "tapping into a more general set of lifestyle factors that were affecting brain health, of which diet is just one part."
"This suggests that lifestyle factors, in this case eating fish, rather than biological factors contribute to structural changes in the brain," Dr. Becker concludes.
Medical News Today recently reported on a study that suggested a simple test of walking speed and memory could predict dementia.