Being overweight in your 60s can age your brain at least a decade, a new study found.
A higher-than-average body mass index, which determines how much a person should weigh depending on age and height, can cause thinning in the brain’s cortex, similarly to what would happen with aging, according to a new study published in the online issue of medical journal Neurology.
Researchers at the University of Miami Miller School of Medicine studied 1,289 people with an average age of 64, two-thirds of whom were Latino. They measured the participants’ BMI and waist circumference at the beginning of the study and conducted an MRI brain scan to measure the thickness of the cortex and overall brain volume six years later.
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About 27% of participants had a BMI of less than 25, which is considered normal, while 44% were classified as overweight and 29% were labeled as obese. People with higher BMIs had thinner cortexes, even after adjusting for various factors, including high blood pressure, alcohol use and smoking, the study found. Having a bigger waist size was also associated with a thinner cortex. “These results are exciting because they raise the possibility that by losing weight, people may be able to stave off aging of their brains and potentially the memory and thinking problems that can come along with brain aging,” said Tatjana Rundek, a neurologist and scientific director of the Evelyn F. McKnight Brain Research Institute
The associations were most prominent in people who were younger than 65, underlying proof of the power that staying healthy in mid-life could have on old age, the researchers said. Brain aging, such as in the form of a thinner cortex, can lead to Alzheimer’s disease. In normal aging, the brain thins at a rate of 0.01 and 0.10 millimeters per decade, but for those who were overweight, the thinning rate was 0.098 millimeters, and for those who were obese, 0.207 millimeters. “Our results would indicate that being overweight or obese may accelerate aging in the brain by at least a decade,” Rundek said.
Also see: One of the big reasons Alzheimer’s goes undiagnosed in older Americans
There are other ways to keep the brain healthy for longer, and potentially delay or deter Alzheimer’s and other types of dementia. Americans use phone apps to keep their brains sharp, but they should also consult doctors about cognitive health check-ups, take brisk walks or jogs and stay active by learning new skills. Cognitive impairment is natural as a person ages -- 6% of people experience it in their 60s across the world, but by 85, more than a third of people have it, according to the American Academy of Neurology.