In the latest Alzheimer’s research, hidden fat in various parts of the body was shown to be an early warning sign of the common dementia — as much as 20 years before symptoms emerged.

The physicians tied a specific type of body fat, known as visceral fat, to higher levels of abnormal proteins in the brain that are indicators of Alzheimer’s. Visceral fat builds up around and between internal organs and can increase the risk of serious health issues. It is different than subcutaneous fat, which is fat just below the skin.

But recent research has indicated that a physical precursor to the disease might manifest on the body long before any cognitive decline is noticed. Scientists have found a link between the amount of visceral fat—also referred to as belly fat situated deep within the abdomen—and the abnormal brain proteins associated with Alzheimer’s.