Health experts have long warned that belly fat can be bad for heart health. A 2018 study, for instance, has shown that people with excess belly fat have twice the risk of suffering from heart attack or die from cardiovascular problems regardless of their weight.

Excess Belly Fat And Brain Shrinkage

Findings of a new study that involved nearly 10,000 people now provide evidence that having excessive fat around the middle may also be bad for the brain.

In a new study, Mark Hamer, from the Loughborough University in Leicestershire, England, and colleagues found that obese people with high waist-to-hip-ratio, a measure of belly fat, tend to have slightly lower brain volumes compared with people with a healthy weight.

The researchers, in particular, found a link between belly fat and lower volumes of gray matter, which contains the neurons and involved in the processing of information in the brain.

The findings of the study, which was published in the journal Neurology on Jan. 9, suggest that the combination of obesity and high waist-to-hip ratio could be a risk factor for brain shrinkage, which has been tied to elevated risk for memory decline and dementia.

"Our research looked at a large group of people and found obesity, specifically around the middle, may be linked with brain shrinkage," Hamer said. "We also found links between obesity and shrinkage in specific regions of the brain."

Study Did Not Prove Causal Link

The study, nonetheless, found only an association between lower brain volume and belly fat. It did not prove that having more fat around the waist can actually cause brain shrinkage. It is possible that individuals with lower volumes of gray matter in some brain areas have increased the risk of obesity.

Cara Bohon from Stanford University School of Medicine, who was not involved in the research, said that the connection between reduced brain volume and belly fat suggests that inflammation and vascular factors may be at play. She also said that something may be affecting both brain volume and risk of obesity.

"For example, if there are nutritional factors impacting brain volume, these same nutritional factors could be a direct cause of obesity," Bohon said.