Where excess body weight gathers could have a major impact on the brain health of older people, with increased belly fat linked to greater cognitive impairment including dementia, a new Irish-based study suggests.
The significant link between belly fat and reduced cognitive function amongst the over-60s was identified in research published by a cross-Border collaboration anchored by Trinity College Dublin.
The study used data from 5,000 people and found that the more belly fat a person has as they age, the more likely they are to suffer cogitative impairment and dementia.
While previous studies have found that people who are overweight do not perform as well on tests of memory and visuo-spatial ability compared to those who are normal weight, the new report focused exclusively on older adults.
"This is of concern within Ireland, as over half of the over-50s population is classified as being centrally obese, with only 16 per cent of men and 26 per cent of women reported to have a BMI (body mass index) within the normal range," the report says.
The researchers used data from the Trinity Ulster Department of Agriculture (Tuda) study, which is a cross-Border collaborative research project gathering data from thousands of elderly adults in Northern Ireland and the Republic.
It found that that belly fat was associated with reduced cognitive function in Irish adults over the age of 60.
The reduced cognitive function 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.
On the contrary, 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), thus it is proposed that the fat-free mass component is likely to be the protective factor.
"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 clinical associate professor in medical gerontology at Trinity, Conal Cunningham, the senior author of the study. "This has significant public health implications."
The study was led by St James's Hospital in Dublin in collaboration with Trinity College Dublin and co-investigators from the Nutrition Innovation Centre for Food and Health at Ulster University, Coleraine.