Diabetes and the Brain: Unclear Evidence
"I think it's a real stretch to call Alzheimer's disease type 3 diabetes," says Janet B. McGill, MD, an endocrinologist and professor of medicine at the Washington University School of Medicine, St. Louis. "We just don't have the evidence."
Kalyani agrees. "We need more research," she says, noting that it's difficult to tease out the effects of diabetes from related conditions. "High blood pressure and obesity often go along with diabetes," she tells WebMD. "It's possible that they could play a role in the increased risk of Alzheimer's disease."
Researchers have also long known that diabetes has effects on the brain aside from those that may be related to insulin levels. Diabetes increases the risk of both major and minor strokes. High glucose may damage brain cells directly, which could cause memory problems and other dementia symptoms.
Insulin and the Brain: What Should I do?
If you have diabetes, the implications of this research may be worrying. Are you at higher risk for conditions such as Alzheimer's disease?
For now, many experts say the evidence is so hazy that people shouldn't dwell on it too much. Frankly, they say, there are plenty of other clearer risks to worry about from diabetes, such as nerve damage, kidney disease, cardiovascular problems, and others.
"There is good news," says Kahn. "Many of the health changes that we associate with diabetes are reversible to a significant extent." Increased exercise, a healthier diet, and in some cases medication can delay or even prevent diabetes-related health risks.
"People with diabetes can sometimes feel helpless," says Kalyani. "But actually, diabetes is a disease that people have some control over." With treatment and lifestyle changes, she says, people can cut their risks of eye, kidney, and nerve problems by up to 70%.
Instead of worrying about a possible link between diabetes and brain conditions, many experts suggest using it as further incentive to get your diabetes under control. We know that monitoring blood sugar, exercising, and eating a healthier diet can have dramatic benefits for your health. It could also have benefits we don't know about yet -- in the brain and elsewhere.