What is the link between blood sugar levels and Alzheimer's disease?

Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
While death rates for cardiovascular disease and prostate cancer have been declining, deaths from Alzheimer’s disease are on the rise. Diets high in sugar have been linked to an increased diagnosis of Alzheimer’s disease. Your blood delivers all kinds of rich nutrients to the brain. But if you have a lot of sugar in your blood, it can cause inflammation. This allows plaque to collect on your neurons, which are where you store your memories. The plaque makes it harder for neurons to fire off signals and causes them to freeze up. Eventually, they are prevented from talking to each other; the information those neurons carry can’t be transmitted or retrieved. When these synapses begin to fail, we begin to see the symptoms of Alzheimer’s.

A fasting blood sugar greater than 100 puts you at a greater risk for Alzheimer’s disease.
This content originally appeared on

There may be a newly discovered bonus to good blood sugar control -- better recall.

Turns out that Alzheimer's disease and the #1 blood sugar disorder, diabetes, share something in common -- something that wreaks havoc on normal brain function -- lack of insulin.

A long-term Swedish study revealed that too little insulin ups Alzheimer's risk. Men with low insulin secretion at age 50 had a significantly greater risk of the mind-robbing disease -- as well as other types of dementia -- later in life. One caveat though is that the link was strongest in men without the gene that predisposes people to Alzheimer's.

Exactly how an impaired insulin response bumps up the Alzheimer's risk isn't clear. But it definitely underscores the importance of diabetes prevention efforts.

Continue Learning about Alzheimer's Disease Causes

Type 3 Diabetes: The Alzheimer’s-Glucose Connection
Type 3 Diabetes: The Alzheimer’s-Glucose Connection
Alzheimer’s disease is common and mysterious, well-documented and hidden. Though it affects an estimated 5.4 million Americans (5.3 million are 65 or ...
Read More
Does my education level affect my risk of Alzheimer's disease?
John H. Growdon, MDJohn H. Growdon, MD
Epidemiologists have found that a disproportionate number of people with Alzheimer's disease are...
More Answers
What are the chances that I will develop Alzheimer's disease as I age?
David A. Merrill, MDDavid A. Merrill, MD
As you get older, there's about a 1% risk per year of developing Alzheimer's disease. Deficits in me...
More Answers
Is Alzheimer's Disease Hereditary?
Is Alzheimer's Disease Hereditary?

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.