By Elizabeth Millard
Extra fat may make your brain shrivel: People who are overweight show more age-related decline in their brains than lean people do, a new study published in Neurobiology of Aging suggests.
After analyzing imaging from 527 adults, the researchers discovered overweight people—those with a body mass index (BMI) over 25—had lower volumes of white matter in their brains than people with a BMI of under 25 did.
White matter is the tissue that connects different areas of your brain with each other and allows for communication between your neural regions. It helps you with everything from memory to thinking quickly.
This tissue naturally shrinks with age, but that process seems to go faster if you’re overweight or obese, says lead researcher Lisa Ronan, Ph.D., a research associate at the University of Cambridge in the U.K.
One possible explanation: Excess fat tissue may produce inflammatory proteins called cytokines, which could hurt your brain, says Ronan.
The researchers didn’t find any differences in cognitive function between overweight and lean people in this study, but prior research has linked extra pounds to an increase in your risk for dementia.
Plus, if the researchers had tested the cognitive function of the participants over time—rather than just the once—it’s possible they’d see cognitive changes emerge, Ronan says.
Regardless, it doesn’t hurt to get your weight under control now: Other research suggests that returning to a normal weight can help improve your brain health.