A new study presented at the annual meeting of the Radiological Society of North America (RSNA) has found a link between a specific type of body fat, visceral fat, and the abnormal proteins associated with Alzheimer’s disease, such as amyloid and tau. These proteins can accumulate in the brain for up to 20 years before dementia symptoms emerge. The researchers suggest that lifestyle changes aimed at reducing this fat could potentially help delay or prevent Alzheimer’s disease. The findings highlight the importance of addressing factors like obesity and fat distribution early in life to reduce the risk of developing dementia later on.
The research focused on the role of modifiable lifestyle factors, such as obesity and body fat distribution, in the development of Alzheimer’s disease. The study specifically examined midlife individuals, around age 49, to understand how obesity and metabolic factors influence the disease’s early stages. The study’s lead author, Dr. Mahsa Dolatshahi, emphasized that midlife is a critical period when interventions, like weight loss and reducing visceral fat, may have the greatest impact on preventing or delaying Alzheimer’s symptoms.
The study involved 80 cognitively normal participants, half of whom were obese, with an average body mass index (BMI) of 32.31. The researchers used a combination of brain positron emission tomography (PET) scans, body MRIs, and metabolic assessments to explore the relationship between obesity, fat distribution, and Alzheimer’s pathology. The MRI scans specifically measured the volume of visceral fat, subcutaneous fat, liver fat, and thigh muscle, while the PET scans identified amyloid and tau deposits in the brain.
The researchers found that higher levels of visceral fat were strongly linked to increased amyloid deposition in the brain, accounting for most of the BMI-related amyloid accumulation. Other types of fat, such as subcutaneous fat, did not show the same relationship with Alzheimer’s pathology. This is the first study to demonstrate this link at midlife, providing new insights into how obesity, particularly visceral fat, may contribute to the early development of Alzheimer’s disease. The study also indicated that insulin resistance and lower levels of HDL (good cholesterol) were associated with higher amyloid levels in the brain.
In addition to the PET scan study, the researchers presented another study showing how obesity and visceral fat affect cerebral blood flow. The findings revealed that individuals with high visceral fat had lower overall brain blood flow, which could further impact brain health and increase Alzheimer’s risk. These studies suggest that addressing obesity and related metabolic issues through lifestyle changes or weight-loss treatments may improve brain function and reduce the risk of Alzheimer’s disease. With obesity affecting a large portion of the population, these insights could have significant public health implications for preventing dementia.
