New research has revealed that hidden fat around internal organs, known as visceral fat, may serve as an early warning sign for Alzheimer’s disease, up to 20 years before symptoms emerge.
The findings, presented at the Radiological Society of North America’s annual meeting, underline the importance of maintaining a healthy lifestyle to potentially reduce the risk of developing the disease later in life.
Led by researchers from Washington University School of Medicine, the study focused on visceral fat—a type of fat that wraps around the internal organs and is not visible externally.
Unlike subcutaneous fat, which lies just beneath the skin, visceral fat has long been associated with metabolic diseases, and now it appears to play a critical role in Alzheimer’s disease as well.
Using advanced imaging techniques, the researchers tracked the buildup of two key proteins linked to Alzheimer’s—amyloid and tau—in the brains of 80 cognitively healthy adults. The participants, with an average age of 49, underwent brain PET scans and body MRIs to assess their fat distribution and brain health.
The most striking finding was that visceral fat was strongly correlated with higher levels of amyloid and tau proteins in the brain. According to Dr. Mahsa Dolatshahi, the study’s lead author, “Higher visceral fat was the most important predictor of whole-brain amyloid and early tau protein accumulation.”
The study also found that metabolic factors associated with visceral fat, such as insulin resistance and low levels of “good” cholesterol (HDL), further contributed to the risk. These findings suggest that managing Alzheimer’s risk in obesity may require addressing metabolic and lipid issues that often accompany high levels of visceral fat.
Senior study author Dr. Cyrus A. Raji explained the broader implications of the findings: “Knowing that visceral obesity negatively affects the brain opens up the possibility that treatment with lifestyle modifications or appropriate weight-loss drugs could improve cerebral blood flow and potentially lower the burden of Alzheimer’s disease.”
Approximately 6.9 million Americans aged 65 and older currently live with Alzheimer’s disease, a number expected to rise to 13 million by 2050. With nearly three out of four Americans classified as overweight or obese, this research highlights the critical need for preventative measures.
The study participants had an average body mass index (BMI) of 32.31, which is classified as obese. Notably, the researchers found that visceral fat accounted for 77% of the effect of high BMI on amyloid and tau accumulation. Other types of fat, including subcutaneous and liver fat, showed no similar correlation.
Although the study’s cross-sectional design means it cannot confirm causation, its findings suggest promising avenues for prevention. Lifestyle changes, such as regular exercise and healthy eating, could significantly reduce visceral fat and improve metabolic health, potentially delaying or even preventing Alzheimer’s onset.
“While we have known for some time that visceral fat facilitates inflammatory changes in various organs, this study demonstrates its impact on the brain,” said Dr. Earnest Lee Murray, a neurologist who was not involved in the study. He emphasized that early intervention could be key to reducing the long-term risk of dementia.