Study finds obesity accelerates brain aging in adults over 65

A 24‑year study of more than 8,200 adults finds that excess body weight can speed up brain aging, causing faster declines in memory, concentration and decision‑making, especially in people over 65. Researchers measured participants’ weight and body‑mass index (BMI) at the start and then tracked changes in brain structure and function using MRI scans and cognitive tests over two decades.

The finding matters because obesity rates have risen sharply worldwide, and the health costs are already felt in heart disease, diabetes and stroke. Scientists have long suspected a link between weight and brain health, but most earlier work relied on short‑term observations or small groups. This new research provides the longest look yet at how body weight interacts with the brain over time, giving a clearer picture of the long‑term risks.

Participants who were classified as overweight or obese at the outset showed brain patterns that appeared up to three years older than their actual age. Each extra point of BMI was associated with roughly a third of a year of added “brain age.” The effect was strongest in the over‑65 group, where obesity added about 1.5 years to brain age and accelerated loss of memory and executive function. Lead author Dr. Maya Patel said the results suggest that carrying extra pounds may compress the window of healthy cognition later in life. Independent experts praised the study’s size and duration but warned that lifestyle factors such as diet quality and physical activity also need to be considered.

The study’s authors say the next step is to test whether weight‑loss interventions can reverse or slow the brain‑aging process. Health agencies are urged to incorporate brain health into obesity guidelines and to promote programs that help older adults maintain a healthy weight. If further research confirms these findings, clinicians may begin to prescribe weight management as a preventive measure for cognitive decline, adding a new dimension to public‑health strategies aimed at an aging population.