Obesity is popularly linked to health issues like diabetes, cancer and cardiovascular disease, but now its effect on the brain is taking center stage.

A new study conducted by the University of Cambridge found that the composition of white matter in the brains of overweight and obese middle-age adults was similar to that of older adults. In short, the younger obese adults brains appeared far more aged.

White matter is tissue that transmits signals in the brain, allowing for communication throughout the body. Loss of white matter, however, corresponds with neurodegeneration, or the loss of neurons in the brain, which leads to the development of diseases such as Parkinson’s, Alzheimer’s and Huntington’s. And that means being overweight could literally damage your brain.

“We’re living in an aging population with increasing levels of obesity, so it’s essential that we establish how these two factors might interact, since the consequences for health are potentially serious,” Paul Fletcher, a professor in the University of Cambridge Department of Psychiatry, said in the study.

As part of the study, researchers collected data from 473 cognitively healthy subjects and split them into lean and obese groups. After gathering images of the white matter in their brains, they discovered that overweight individuals had far less white matter than their leaner counterparts. In fact, the reduced amount of white matter in their brains was in line with that of lean subjects 10 years older.

Researchers only saw the differences in white matter in middle-aged and older participants, which led to another revelation about the mind being vulnerable starting at an older age. However, the researchers stressed that obesity was not found to have an effect on intelligence or cognition, rather just the aging of the brain.

Whether these these changes in white matter could be reversible with weight loss remains in question, but the authors say it’s a starting point for a more in-depth exploration of the effects of weight.

But what we do know is that exercise has many positive impacts on the brain, including longevity.