A new study using data from more than 5,000 people has found that a higher percentage of belly fat was associated with reduced cognitive function in Irish adults older than 60.

Previous studies have found that people who are overweight do not perform as well on tests of memory and visuospatial ability compared to those who are normal weight, said researchers at Trinity College Dublin in Ireland.

This is of concern in Ireland, as over half of the population over the age of 50 is classified as being obese, with only 16 percent of men and 26 percent of women reported to have a body mass index (BMI) within the normal range, researchers say.

For the new study, researchers used data from the Trinity Ulster Department of Agriculture (TUDA) aging cohort study, a collaborative research project gathering data from thousands of elderly adults in Northern Ireland and Ireland.

The researchers found that a higher waist to hip ratio was associated with reduced cognitive function.

This could be explained by an increased secretion of inflammatory markers by belly fat, which has been previously associated with a higher risk of impaired cognition, according to the researchers.

The researchers also found that a healthy BMI was found to protect cognitive function. BMI is a crude measure of body fat and cannot differentiate between fat and fat-free mass — muscle — which leads the researchers to propose that the muscle is likely the protective factor.

Given the high prevalence of overweight and obesity in the older population and the economic and social burden of cognitive dysfunction, the study’s findings suggest that reducing obesity could offer a cost-effective public health strategy for the prevention of cognitive decline, the researchers noted.

“While we have known for some time that obesity is associated with negative health consequences, our study adds to emerging evidence suggesting that obesity and where we deposit our excess weight could influence our brain health,” said Conal Cunningham, clinical associate professor in medical gerontology at Trinity and senior author of the study. “This has significant public health implications.”

Source: Trinity College Dublin