Dr. Suzanne de la Monte is a researcher who conducts scientific studies on the link between Alzheimer’s disease and diabetes mellitus type 2. And yes, there appears to be a connection between the two.

Preliminary studies appear to show a strong correlation between having type 2 diabetes – the form of the disease that usually strikes in adulthood – and developing Alzheimer’s disease, a degenerative disease of the brain. “Type 3 diabetes” is a term that has been used to refer to the association of lower-than-normal brain insulin levels and Alzheimer’s disease.

“The results from these studies provide some evidence to support the hypothesis that Alzheimer’s represents a form of diabetes mellitus that selectively affects the brain,” says Dr. de la Monte, professor of pathology and laboratory medicine and professor of neurosurgery at Brown University in Providence, Rhode Island, who has authored several studies on the subject.

The take-away? When it comes to Alzheimer’s, “diabetes is a risk factor,” explains Dr. Sandra Black, senior scientist and director of Evaluative Clinical Sciences, Hurvitz Brain Sciences Research Program at the Sunnybrook Health Sciences Centre in Toronto. Dr. Gordon Glazner, associate professor in the Department of Pharmacology and Therapeutics at the University of Manitoba and principal investigator, Division of Neurodegenerative Disorders at St. Boniface Hospital Research Centre in Winnipeg, agrees. “Preventing type 2 diabetes will reduce your risk,” he says.

That’s not to say other factors don’t play a part; some research has shown that having certain genes can predispose you to Alzheimer’s, as can head trauma and heart disease.

The diabetes-Alzheimer’s connection

Type 2 diabetes occurs when the body stops producing insulin or it can no longer use the insulin it does make, because its insulin receptors are not functioning properly. This results in elevated blood glucose levels. Up to a certain point, the condition is called pre-diabetes; beyond that, it’s full-fledged diabetes.

Scientists have found that a similar process may happen in the brain. In the brains of people with Alzheimer’s, insulin receptors don’t receive the proper hormonal support, and over time, the neurons may become damaged and not function properly.

And that process could lead to the symptoms of Alzheimer’s, which include:

  • loss of memory
  • lowered ability to make decisions
  • personality changes
  • mobility issues

How to prevent diabetes – and possibly Alzheimer’s

Many cases of type 2 diabetes, which affects 3 million Canadians, can be prevented. Smoking, high blood pressure, carrying extra weight and lack of exercise are all risk factors for the disease – and are all modifiable. Reducing your risk of developing type 2 diabetes may help to reduce your risk of developing Alzheimer’s as well.

Here’s what to do: Consult with your personal physician before making changes to your lifestyle and eating habits.

  1. Keep your weight in a healthy range.
  2. Eat a diet that includes 5 to 10 servings of fruit and vegetables every day, more fibre and less fat.
  3. Be active for a minimum of 30 minutes every day.
  4. Manage your blood pressure. Keep tabs on your readings and, on the advice of your GP, lower it with medications.
  5. Keep an eye out for symptoms of type 2: increased thirst and urination, skin infections that won’t heal, fatigue, weight loss, increased appetite and blurred vision.
  6. Quit smoking.

Type 2 diabetes can be reversed in some cases, says Glazner. An aggressive exercise campaign, sensible diet and weight loss can work wonders. Eating a lower-carbohydrate diet may also stabilize blood sugar (helpful in staving off type 2 diabetes) as well as help manage symptoms in Alzheimer’s patients.

At the moment, there aren’t any standard treatments for preventing Alzheimer’s in patients with type 2 diabetes. Various experimental treatments are being developed, involving medications, delivery systems and stem cell research.