Does carrying excess body weight, meaning inflammatory visceral fat tissue that distorts metabolism in many ways, actually accelerate the processes of aging, or just make all later life health issues worse and shorten life expectancy via unrelated mechanisms? The evidence leans in the direction of actually accelerating aging. Regardless, by now we should all be used to the headlines announcing that yet another aspect of age-related degeneration proceeds faster in overweight individuals.
Having a bigger waistline and a high body mass index (BMI) in your 60s may be linked with greater signs of brain aging years later, according to a new study that suggests that these factors may accelerate brain aging 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 gray matter of the brain. 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 aging and problems with memory and thinking skills in later life."
The study involved 1,289 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. 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 0.098 millimeter thinner cortex and in obese people with a 0.207 mm thinner cortex. Having a thinner cortex has been tied to an increased risk of Alzheimer's disease. Having a bigger waist was also associated with a thinner cortex after adjusting for other factors.
"In normal aging adults, the overall thinning rate of the cortical mantle is between 0.01 and 0.10 mm per decade, and our results would indicate that being overweight or obese may accelerate aging in the brain by at least a decade. 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. 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."