Scientists discover hidden danger of obesity to the brain

Scientists at Louisiana State University have found that long-term obesity is linked to poorer brain health in middle age. According to the study, signs indicating damage to small blood vessels in the brain are twice as common in people who have experienced clinical obesity. The results were published in the journal Neurology Open Access.

The study involved 190 participants from the "Bogalusa Heart Study" project, which began in 1972. Their health has been monitored since 1985, and brain MRI scans were conducted between 2017 and 2025 when the participants' average age was 56.5 years. Out of the participants, 133 people—or 70 percent—experienced clinical obesity at some point in their lives.

Using not only the body mass index but also the criteria of "The Lancet" Commission, the scientists separated metabolically healthy obesity from clinical obesity accompanied by metabolic disorders.

The results showed that the longer a person lived with clinical obesity, the more signs known as white matter hyperintensity were present in their brain. These signs, which appear as bright spots on an MRI, are associated with damage to the small blood vessels of the brain. In people over 50 who suffered from clinical obesity, such signs were found to be twice as frequent compared to participants who had never experienced obesity.

"People who experienced clinical obesity for decades had worse brain health in middle age," said lead researcher Owen Carmichael.

Experts note that this condition may be related to high blood pressure, diabetes, and lipid metabolism disorders. In addition, inflammatory processes in the body and insulin resistance are also likely to affect the brain's blood vessels.

However, the study is observational in nature and does not prove that obesity directly causes brain damage. The small number of participants and the fact that the MRI scan was performed only once are also considered limitations of the study.

The scientists noted that such signs in the brain do not necessarily mean dementia or impaired cognitive abilities. Nevertheless, the results indicate that long-term clinical obesity can be a risk factor for cerebrovascular health.