Recent Blog Articles
New advice on melatonin use in children
How to choose period products
Vaccines against the flu and COVID-19: What you need to know
Treatments for rheumatoid arthritis may lower dementia risk
Scoring highly on Alternative Healthy Eating Index lowers risk for many illnesses
Can self-employment promote better cardiovascular health for women?
Why is it so challenging to find a primary care physician?
Harvard Health Ad Watch: A new injection treatment for eczema
3 simple swaps for better heart health
I’m too young to have Alzheimer’s disease or dementia, right?
Diseases & Conditions
High blood sugar linked to brain shrinkage
What this means for preventing cognitive decline
If your blood sugar is on the high end of the normal range, diabetes may not be your only risk. A recent study in Neurology suggests you're also at risk of brain shrinkage in areas associated with memory and thinking. "I do think that this is a legitimate association. However, we don't know if blood sugar causes it," says Dr. Gad Marshall, a neurologist at Harvard-affiliated Brigham and Women's Hospital.
A normal fasting blood sugar level is 70 to 100 milligrams per deciliter (mg/dL). Fasting is defined as at least six hours without eating or drinking anything with calories. A fasting level of 100 to 125 mg/dL indicates you have "prediabetes" and are at increased risk for developing diabetes. A fasting level of 126 mg/dL and higher signifies that you probably have diabetes.
To continue reading this article, you must log in.
Subscribe to Harvard Health Online for immediate access to health news and information from Harvard Medical School.
- Research health conditions
- Check your symptoms
- Prepare for a doctor's visit or test
- Find the best treatments and procedures for you
- Explore options for better nutrition and exercise
I'd like to receive access to Harvard Health Online for only $4.99 a month.Sign Me Up
Already a member? Login ».
As a service to our readers, Harvard Health Publishing provides access to our library of archived content. Please note the date of last review or update on all articles.
No content on this site, regardless of date, should ever be used as a substitute for direct medical advice from your doctor or other qualified clinician.
Free Healthbeat Signup
Get the latest in health news delivered to your inbox!