Having a bigger waistline and a high body mass index (BMI) in your 60s may be linked with greater signs of brain ageing years later, according to a study published by a leading University of Miami neurology researcher.
The study suggests that these factors may accelerate brain ageing by at least a decade.
“People with bigger waists and higher BMI were more likely to have thinning in the cortex area of the brain, which implies that obesity is associated with reduced grey matter of the brain,” said study author Tatjana Rundek.
“These associations were especially strong in those who were younger than 65, which adds weight to the theory that having poor health indicators in mid-life may increase the risk for brain ageing and problems with memory and thinking skills in later life,” said Dr Rundek.
The study involved 1289 people with an average age of 64.
Participants’ BMI and waist circumference were measured at the beginning of the study. An average of six years later, participants had MRI brain scans to measure the thickness of the cortex area of the brain, overall brain volume and other factors.
A total of 346 of the participants had a BMI of less than 25, which is considered normal weight; 571 people had a BMI of 25 to 30, which is considered overweight, and 372 people had a BMI of 30 or higher, which is considered obese.
For waist circumference, which can be different for men and women, the normal weight group, which was 54 per cent women, had an average of 84 centimetres; the overweight group, which was 56 per cent women, had an average of 91.5 centimetres, and the obese group, which was 73 per cent women, had an average of 104 centimetres.
Having a higher BMI was associated with having a thinner cortex, even after researchers adjusted for other factors that could affect the cortex, such as high blood pressure, alcohol use and smoking.
In overweight people, every unit increase in BMI was associated with a 0.098mm thinner cortex and in obese people with a 0.207mm thinner cortex.
Having a thinner cortex has been tied to an increased risk of developing Alzheimer’s disease.
Having a bigger waist was also associated with a thinner cortex after adjusting for other factors.
“In normal ageing adults, the overall thinning rate of the cortical mantle is between 0.01 and 0.10mm per decade, and our results would indicate that being overweight or obese may accelerate ageing in the brain by at least a decade,” Dr. Rundek said.
“These results are exciting because they raise the possibility that by losing weight, people may be able to stave off ageing of their brains and potentially the memory and thinking problems that can come along with brain ageing,” she added.
“However, with the rising number of people globally who are overweight or obese and the difficulty many experience with losing weight, obviously this is a concern for public health in the future as these people age.”
Do you think living a healthy lifestyle can help prevent brain ageing? What steps are you taking to prevent cognitive decline?
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