Researchers Find Association Between Extra Weight in 60s and Brain Thinning

According to a study published in Neurology, the medical journal of the American Academy of Neurology, having a high body mass index (BMI) and a bigger waistline in your 60s may be associated with brain thinning in later life. Brain thinning affects the cortex, which is the area in the brain that determines intelligence, personality, motor function, the process of sensation, as well as language processing.

The study was co-authored by University of Miami Miller School of Medicine’s Dr. Tatjana Rundek, professor of neurology, epidemiology, and public health, Michelle Caunca, a third-year M.D./Ph.D. in epidemiology candidate at the Department of Public Health Sciences, and various other researchers. 

"Our data shows that greater BMI and waist circumference are associated with thinner cortices. We hope our findings lead to further research questions about how addressing obesity may impact brain aging in the population," Caunca said, who was the lead author on the study.   

The study examined data from the Northern Manhattan Study, which included 1,289 people who were aged 64 years, were 60 percent women and 66 percent Hispanic. At the beginning of the study, they had their body mass index (BMI) and waist circumference measured. 

There were 346 participants that had a normal BMI of less than 25, as well as 571 that had 25 to 30, which is considered overweight, and 372 with 30 or higher, which is considered obese.

In terms of waist circumference, 54 percent of women were in the normal weight category with an average of 33 inches, 56 percent were in the overweight category with an average of 36 inches, and 73 percent were in the obese category with an average of 41 inches.

Six years later, they had MRI scans to measure the thickness of their cortex, their brain volume, and other factors.

Results showed that with every unit increase in BMI in overweight participants, there was an association with a 0.098-millimeter thinner cortex. Among those with obesity, there was an association with a 0.207-millimeter thinner cortex.

“Poor brain health in aging populations is an urgent public health concern with the growing burden of dementia in the U.S. There is a lack of curative therapies for dementia, so focusing on modifiable risk factors can help attenuate the burden of cognitive impairment,” Caunca said.  

Written by Amanda Torres

Published on August 6, 2019