Visceral fat encases the organs deep in the body, wreaking havoc via inflammation and excess hormones that can disrupt the body's ability to process insulin. (Science Photo Library/Getty Images via CNN Newsource)
A new study has revealed that changes in brain health linked to obesity can start much earlier than expected — potentially in a person's 40s or 50s, well before any noticeable cognitive decline. As a person's belly grows, researchers found that certain areas of the brain, particularly those involved in memory, can begin to shrink. Additionally, signs of Alzheimer’s disease, such as beta amyloid plaques and tau tangles, can appear decades before the onset of symptoms.
Beta amyloid plaques generally appear first, followed by tau tangles as the disease progresses. According to Dr. Cyrus Raji, a senior researcher and associate professor of radiology at Washington University School of Medicine, these plaques and tangles are associated with the deterioration of brain function. “The more amyloid or tau you have, the sicker the brain becomes,” he explained, noting that this brain damage is often reflected in reduced blood flow and a loss of gray matter in regions such as the hippocampus, which is crucial for memory.
Dr. Richard Isaacson, a preventive neurologist at the Institute for Neurodegenerative Diseases in Florida, emphasized that the study’s findings highlight the importance of managing belly fat as a preventive measure against Alzheimer's. He pointed out that this research links obesity to brain changes long before any cognitive symptoms appear, making it vital to focus on reducing belly fat early on.
Obesity has become a global health crisis, with the World Health Organization predicting that more than half of the world’s population will be overweight or obese in the next decade. In the United States alone, nearly 260 million people may be affected by obesity by 2050, contributing to a rise in Alzheimer’s cases. Raji pointed out that obesity could already be responsible for up to 2 million cases of dementia in the U.S.
One Key Factor Is Visceral Fat
In a pilot study conducted by Raji's team, visceral fat was linked to brain inflammation and the buildup of amyloid plaques in the brains of men and women in their 40s and 50s. Unlike the more common subcutaneous fat, visceral fat is metabolically active and more likely to cause health problems such as insulin resistance and diabetes. It also receives more blood flow, making it more likely to contribute to inflammation.
Raji’s study, which used advanced imaging techniques like PET scans and MRIs, found that increased visceral fat levels were associated with brain atrophy in areas like the hippocampus, which is critical for memory function. The latest findings, presented at a medical conference in November 2024, revealed for the first time that higher amounts of visceral fat were also linked to the buildup of tau tangles, another hallmark of Alzheimer’s.
Dr. Isaacson emphasized that this research is crucial for the millions of people who may have early signs of Alzheimer’s but haven't yet shown symptoms. Reducing visceral fat through lifestyle changes could be an effective strategy for slowing or even preventing the disease.
To Combat Belly Fat
Experts suggest focusing not just on body weight but on body composition. Dr. Isaacson recommends using a biometric scale or an annual DEXA scan, which tracks muscle mass and fat levels, to monitor progress. He also advocates for regular exercise, particularly "Zone 2" training, which involves walking at a brisk pace for 45 to 60 minutes two to three times a week. Strength training is another key component of fat loss, as building muscle increases metabolism and helps burn fat.
By focusing on these strategies, individuals can not only improve their overall health but potentially reduce their risk of developing Alzheimer's later in life.
