Science and Technology Daily, Beijing, November 11 (Reporter Zhang Jiaxin) According to a study to be published at the annual meeting of the Radiological Society of North America, there is a correlation between the higher content of abdominal visceral fat in middle age and the occurrence of Alzheimer's disease. The earliest symptom of Alzheimer's disease is memory impairment, and studies have found that this "invisible" belly fat is associated with brain changes up to 21 years before the symptom occurs.

In an attempt to determine the risk of Alzheimer's disease earlier, the researchers evaluated the relationship between brain volume measured by magnetic resonance imaging and the uptake of amyloid and tau protein in positron emission tomography (PET) and body mass index (BMI), obesity, insulin resistance, and visceral fat in cognitively normal middle-aged people.

The researchers analyzed data from 54 participants, who ranged in age from 40 to 60 years old and had an average BMI of 32. It was found that a higher visceral fat-to-subcutaneous fat ratio was associated with higher precuneus cortical amyloid PET tracer uptake, an area known to be influenced by amyloid pathology in early Alzheimer's disease. This relationship is more severe in men than in women. The researchers also found that higher visceral fat measurements were associated with an increased inflammatory burden in the brain.

Inflammatory secretions from visceral fat may cause inflammation of the brain, one of the main mechanisms that trigger Alzheimer's disease, researchers say. Studies have shown that this brain change occurs as early as age 50, 15 years before the earliest symptoms of memory loss in Alzheimer's disease. These findings have important implications for early diagnosis and intervention, and visceral fat may be a therapeutic target to reduce the risk of brain inflammation and dementia in the future.