Study reveals overweight older men have reduced risk of dementia

New results from a decade-long epidemiological study have shown that overweight older men are less likely to develop dementia.

The results, published in PLoS ONE Journal, indicate that men with a body mass index (BMI) in the overweight category and with high measurements of fat deposits around the waist were less likely to develop dementia compared to their normal weighted peers.

The study surveyed 12,047 community-dwelling men aged between 65 and 84 years over a 10-year period.

“We found that older men who have more body fat around their waist are less likely to develop dementia,” said Winthrop Professor Osvaldo Almeida, Chair of Old Age Psychiatry at The University of Western Australia and Research Director Western Australian Centre for Health and Ageing, based at the Western Australian Institute for Medical Research.

“There is some controversy over whether obesity guidelines that have been developed for adults should be applied to the elderly.

“It is well established that obesity is a contributing factor for many lifestyle diseases such as cardiovascular disease and diabetes, which in turn increases the risk of death in middle age. However, the same may not true for older men.

“Recent research has shown that being classified as overweight in old age reduces your chance of dying from cancer, heart attack, stroke and other diseases that are associated with old age. Our findings add further weight to the argument for the need to review the BMI for the elderly.

“These findings have relevance to the ongoing debate about developing suitable BMI guidelines for later life: older men who have a slight increase in adiposity markers are not at greater risk of dementia, and current guidelines for ‘healthy’ adiposity values for BMI, waist circumference and waist/hip ratio might require recalibration in older age.”

Professor Almeida said the prevalence of obesity in older Australians had tripled between 1985 and 2004, affecting 22% of men aged 65-74 and 14% of those older than 75 years.

“The strength of our study is that, to our knowledge, it is the largest, longest epidemiological survey of old men and dementia,” he said.

“Many other studies have looked at far fewer men. We cannot comment on whether the findings would apply to older women, without doing further research with women.”