That’s what researchers in a joint Group Health–University of Washington (UW) study set out to determine. Following more than 2,000 patients age 65 and older, they averaged blood sugar levels over a five-year period and found that, in people without diabetes, risk for dementia was 18% higher for people with an average glucose level of 115 milligrams per deciliter (mg/dl) compared to those with an average glucose level of 100 mg/dl. And in people with diabetes, whose blood sugar levels are generally higher, dementia risk was 40% higher for people with an average glucose level of 190 mg/dl compared to those with an average glucose level of 160 mg/dl. “We don’t know the reason for the link between high blood sugar levels and dementia, but we do know that the risk levels are lower than those that we normally start to worry about,” says lead author of the New England Journal of Medicine study Paul K. Crane, M.D., MPH. “This is an observational study, so we don’t know if glucose itself is the bad actor or if it’s something associated with glucose.” It may not help to back away from that donut. As Dr. Crane, who is an associate professor of medicine at the UW School of Medicine, points out, this is just a step in the research linking blood sugar and dementia risk, not a “change what you’re doing” kind of study. However, Dr. Crane is not completely adverse to lifestyle advice. “Exercise is probably a good thing and is well-tolerated and people seem to enjoy it,” says Dr. Crane. “I would say that people who exercise more tend to have blood sugar levels lower than those who exercise less.” More from Prevention: How Stress Impacts Blood Sugar Levels Nature’s Best Blood Sugar Blockers
