Non-overweight individuals in their late 60s, 70s, and early 80s who have no outward symptoms of Alzheimer’s are more likely than their heavier peers to have biological markers (or biomarkers) of the disease, the study found. This finding raises the possibility that weight loss or a low body mass index (BMI) later in life may be an early warning sign of mental decline, the researchers say.
“Weight changes or body composition changes may actually be a manifestation of disease, which would explain the obesity being an apparent protective factor,” says Jeffrey M. Burns, MD, the lead author of the study and the associate director of the University of Kansas Alzheimer’s Disease Center, in Kansas City.
Well before memory loss and other symptoms appear, Alzheimer’s may trigger metabolism changes that promote weight loss, Burns says. “In general, we think of Alzheimer’s as a brain disease, but this is evidence that there are systemic problems throughout the body in the early stages of Alzheimer’s.”