How to Keep Your Marbles

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By : dLife Editors

You may already know that keeping your blood glucose under tight control can help you avoid a variety of diabetic complications. But did you know that it might also help you hang onto your cognitive function?

Several medical studies suggest that extreme blood glucose levels—too high and too low—interfere with normal cognitive function, and may even increase the risk of developing Alzheimer’s disease.

Granted, we’ve all been embarrassed by those forgetful moments when we can’t remember where we’ve left our keys, or if we left the coffee pot on. That type of occasional forgetfulness is normal and nothing to worry about—but regularly feeling fuzzy-brained can be a sign of poor glycemic control.

The Blood Sugar/Brain Connection

The problem begins with normal age-related changes in the brain. According to one study published in 2014, cognitive skills may begin to slow and decline at around age 24, and continue to decline by 15 percent every 15 years thereafter.

Several studies, however, indicate that elevated blood glucose levels can make matters much worse. A study published in 2013 showed that above-normal blood sugar is associated with an increased risk of developing dementia, even in people without diabetes.

The risk is even greater for people with diabetes. According to the 2013 study, the risk for dementia is 40 percent higher in people with diabetes with blood sugar levels averaging around 190, as compared to those with blood sugar averaging around 160.

Impaired blood flow may also play a role in the increased dementia risk in people with diabetes. According to a 2015 study published in the journal Neurology, people with type 2 diabetes experienced decreased blood flow in the brain, which was associated with lower scores on tests of cognitive skills and an impaired ability to perform daily tasks.

Low blood glucose can also be problematic. Research has also found that older adults with diabetes who experience severe episodes of low blood sugar have twice the risk of developing dementia as those who have not had a hypoglycemic episode. In addition, dementia can make people less able to manage their diabetes, which can lead to further episodes of low blood sugar, creating a vicious cycle.

Bottom line: Evidence of a link between diabetes and dementia is piling up, giving you even more reasons to do all you can to maintain good glycemic control.

Four Keys to Staying Sharp

  1. Focus on healthy eating habits. Opt for a wholesome, low-glycemic diet that helps you maintain optimal blood glucose control.
  2. Consistently take your prescribed diabetes medications.
  3. Incorporate some physical activity into your life. At the very least, go for a daily 30-minute walk. Building lean muscle tissue improves how your body utilizes both blood glucose and insulin.
  4. Ask your doctor about having some nutrient-level testing, and takingvitamin supplements. A 2014 review suggests that supplements of Vitamin E may help support healthy brain function and delay functional decline related to Alzheimer’s disease.

Jack Challem, The Nutrition Reporter™, is a member of the American Society for Nutrition and one of America’s most trusted nutrition and health writers. He is the bestselling author of more than twenty books, including Stop Prediabetes Now, and gives nutrition presentations across the United States and around the world.


Chung, C.C., Pimentel, D., Jor’dan, A.J., et al. “Inflammation-Associated Declines in Cerebral Vasoreactivity and Cognition in Type 2 Diabetes.” Neurology. August 2015.

Crane, P.K., Walker, R., Hubbard, R.A., et al. “Glucose Levels and Risk of Dementia.” New England Journal of Medicine. Updated September 26, 2013.

Devore, E., Grodstein, F., et al. “Dietary Antioxidants and Long-Term Risk of Dementia.” Archives of Neurology. July 2010.

Fischer, A.L., de Frias, C.M., Yeung, S.E., et al. “Short-Term Longitudinal Trends in Cognitive Performance in Older Adults with Type 2 Diabetes.” Journal of Clinical and Experimental Neuropsychology. October 2009.

La Fata, G., Weber, P., and Mohajeri, M.H. “Effects of Vitamin E on Cognitive Performance During Aging and in Alzheimer’s Disease.” Nutrients. November 2014.

Thompson, J.J., Blair, M.R., and Henrey, A.J. “Over the Hill at 24: Persistent Age-Related Cognitive-Motor Decline in Reaction Times in an Ecologically Valid Video Game Task Begins in Early Adulthood.” PLoS One. April 9, 2014.

Yaffe, K, Falvey, C.M., Hamilton, N., et al. “Association Between Hypoglycemia and Dementia in a Biracial Cohort of Older Adults with Diabetes Mellitus.” JAMA Internal Medicine. July 2013.

 Updated 11/16.