In a new study published in the journal Alzheimer’s & Dementia, researchers looked at data from 1.3 million US and European adults and found a higher BMI could help predict their dementia diagnosis 20 years before the actual onset: According to the results, for every five-unit increase in BMI—which equals about 32 pounds for a five-foot-seven-inch person—there was up to a 33 percent higher risk of the disease.
Even more interesting? Though having a high BMI years—or even decades—ahead of developing dementia may have a predictive correlation, research shows it’s also relatively common to have a lower-than-average BMI right before the diagnosis. It’s quite the boomerang effect.
“People who develop dementia may have a higher-than-average body mass index some 20 years before dementia onset, but closer to overt dementia, have a lower BMI than those who remain healthy.” —Mika Kivimäki, PhD
“The BMI-dementia association, is actually attributable to two processes,” said lead study author Mika Kivimäki, PhD, in a press release. “One is an adverse effect of excess body fat on dementia risk. The other is weight loss due to pre-clinical dementia. For this reason, people who develop dementia may have a higher-than-average body mass index some 20 years before dementia onset, but closer to overt dementia, have a lower BMI than those who remain healthy.”
Ultimately, the study authors say maintaining a healthy weight could prevent or delay dementia later in life, so invest in your well-being by eating a nutritious diet, getting an appropriate amount of sleep, and exercising regularly.