Researchers have found that abdominal fat is associated with changes in the brain long before the first symptoms of Alzheimer’s disease appear.
- The frequency of Alzheimer’s disease increases with age. Rare before the age of 65, it affects 23% of the population after the age of 80. To date, it is estimated that 1.2 million people are affected in France.
- According to the study, high levels of abdominal fat are associated with an increased risk of Alzheimer’s disease.
- This is the first time a study has linked this specific type of fat to proteins associated with the development of neurodegenerative disease.
Not all fats are equal. Abdominal, or visceral, fat is the part of adipose tissue, located under the muscles of the abdomen, which surrounds the internal organs (liver, stomach and intestines). It differs from subcutaneous fat, stored under the epidermis, and intramuscular fat, distributed between muscle fibers. To summarize, it is the belly fat that we often try to lose, and not without difficulty, around our forties.
Rightly so, because it increases the risk of diseases such as type 2 diabetes or cancer. According to a new study, which will be presented at the end of November during the annual meeting of the North American Society of Radiology (RNSA), visceral fat is even associated with the development of Alzheimer’s disease.
Abdominal fat associated with tau protein accumulation
To reach this conclusion, researchers from Mallinckrodt Institute of Radiology (MIR), in the United States, analyzed data from 54 participants aged 40 to 60, in good cognitive health, with an average BMI of 32. They measured their glucose and insulin levels, as well as their volumes of subcutaneous fat and abdominal fat using MRI scans. They then assessed the levels of amyloid and tau proteins in their brains, the accumulation of which is known to be toxic to neurons and the cause of Alzheimer’s disease.
As a result, the researchers found that higher amounts of abdominal fat were associated with a higher rate of absorption of the proteins in question in the precuneus cortex, a region of the brain known to be affected very early by the disease, but also with an increase in inflammation in the brain. This is the first time a study has linked this specific type of fat to “Alzheimer’s proteins.”
“Inflammatory secretions of visceral fat – as opposed to the potentially protective effects of subcutaneous fat – may lead to inflammation of the brain, one of the main mechanisms contributing to Alzheimer’s disease”explains in a communicated researcher Mahsa Dolatshahi, who participated in the study.
Hidden fats may increase risk of Alzheimer’s disease
“This study highlights a key mechanism by which hidden fats may increase the risk of Alzheimer’s disease, agrees with his colleague Cyrus A. Raji, professor of radiology and neurology.. This shows that such brain changes occur from the age of 50 on average, about 15 years before the first symptoms of memory loss in Alzheimer’s disease appear.
The authors hope that their work will make it possible to consider visceral fat as a new target for therapeutic treatment, in order to reduce the risks of future brain inflammation and dementia.
