Body weight may play a larger role in brain aging than previously understood.
A number on the scale may say more about future brain health than previously recognized.
New research from the University of Georgia suggests that higher body mass index, or BMI, may be linked to faster cognitive decline in older adults. The finding adds to growing evidence that metabolic health, blood flow, and inflammation may all shape how the brain ages.
Some changes in memory and thinking are normal with age. People may need more time to recall names, process information, or concentrate. In healthy adults, these shifts usually happen slowly.
In this study, however, higher BMI over time was associated with sharper declines in memory, overall cognitive ability, and executive functioning. These skills help people plan, stay organized, manage emotions, focus attention, and complete everyday tasks.
A Long-Term Look at Brain Healing
The researchers analyzed data from a nationally representative study that tracked more than 8,200 adults over age 50 for 24 years.
They found that each one-unit increase in BMI was linked to a faster decline in brain health.
Still, the results also offered a hopeful message.
“We found that if people managed their weight, they could significantly lower their rate of cognitive decline in just two years,” said Suhang Song, lead author of the study and an assistant professor in UGA’s College of Public Health. “That makes BMI one of the most easily modifiable risk factors when it comes to aging well.”
The link between BMI and cognitive decline was strongest in the eighth year of the study. The association was especially clear among adults older than 65.
