Being overweight during one’s early 40s increases the risk of Alzheimer’s disease decades later, new research shows.
“We originally thought that once we took into account diabetes and cardiovascular disease, that there would be no effect of overweight on Alzheimer’s disease, but that turned out not to be the case,” Dr. Rachel A. Whitmer said at a press briefing held at the American Academy of Neurology’s annual meeting here in San Diego.
Whitmer, from the Kaiser Permanente Foundation Research Institute in Oakland, California, and her colleagues studied data on nearly 9000 men and women who were between the ages of 40 and 45 years old when they were first examined between 1964 and 1973. Body fat was measured in the back and arms using special calipers.
During an average follow-up period of 23 years, 221 cases of Alzheimer’s disease were diagnosed.
After factoring in the effects of diabetes, stroke, high cholesterol levels, and high blood pressure, “we observed a strong independent effect for people with high levels of adiposity” in middle age, Whitmer said. Subjects with high levels of fat in the arm and back were nearly three times more likely to develop Alzheimer’s disease than those with low levels.
The association was even stronger when taking into account body mass index (BMI), an overall measure of body weight in relation to height, the researcher added.
“BMI is a good marker for overweight and obesity, but it does not take into account fat regional distribution,” she told Reuters Health. This may mean that “even if a person is of normal weight, carrying a lot of fat in certain areas, especially the (trunk), puts people at risk.”
“Doctors need to remind people that they need to think about weight in middle age,” she said. Losing excess weight and body fat in middle age is not just good for the heart, it’s also good for the brain.
Whitmer and her team plan to evaluate whether weight loss reduces the risk of Alzheimer’s disease.