Being overweight in adulthood leads to health complications such as diabetes, hypertension or dyslipidemia. Obesity is increasingly recognized as a multisystem disease affecting the respiratory, gastrointestinal and cardiovascular systems.

Previous studies have shown an association between obesity and AD-related changes such as amyloid buildup and cerebrovascular dysfunction. However, no study has yet directly compared the patterns of brain atrophy in AD and obesity.

A new study by scientists at McGill University’s The Neuro (Montreal Neurological Institute-Hospital) finds a correlation between neurodegeneration in obese people and patients with Alzheimer’s disease (AD).

Scientists examined patterns of gray matter shrinkage in obesity and Alzheimer’s disease using a sample of more than 1,300 people. They made maps of gray matter atrophy for each group and compared AD patients with healthy controls and obese and non-obese people.

The scientists found that the effects of obesity and AD on gray matter thinning were similar. For example, both groups showed similar levels of thinning in the left prefrontal cortex and right temporoparietal cortex. Neurodegeneration can be indicated by cortical thinning. This implies that obesity can lead to the same kind of neurodegeneration as AD patients.

Filip Morys, a Ph.D. researcher at The Neuro and the study’s first author, said: “Our study reinforces previous literature pointing to obesity as an important factor in AD by showing that cortical thinning could be one of the potential mechanisms of risk. Our results suggest that, among other health benefits, reducing weight in obese and overweight people in middle age may also reduce the subsequent risk of neurodegeneration and dementia.”

This study, published in the Journal of Alzheimer’s Disease on January 31, 2022, also helps reveal a neurological impact, showing that obesity may play a role in the development of Alzheimer’s and dementia.