Diabetes Developed at Midlife May Affect Brain Function in Old Age

Developing Type 2 diabetes during middle age can affect mental function in later years by shrinking the brain, according to research recently published in the journal Neurology. Approximately 26 million people in the United States have Type 2 diabetes, while another 79 million have prediabetes and are at increased risk of developing Type 2.


To determine the associations of Type 2 diabetes and high blood pressure with mental function, researchers looked at 1,437 adults with a median age of 80 years who did not have dementia. Using medical records, the participants were placed into three groups: those who developed diabetes or high blood pressure in midlife (ages 40 to 64), those who developed one or both of the conditions in late life (age 65 years or older), and those who had never developed the conditions. The average age for developing diabetes was 56.2 for midlife and 71.9 for late life, while the average age of developing high blood pressure was 52.7 for midlife and 71.6 for late life.

The participants had their thinking and memory skills regularly tested, with any signs of impairment being noted. They also underwent magnetic resonance imaging, or MRI, scans to check their brains for signs of damage.

The researchers found that, compared to people who did not have diabetes, those who had developed the condition at midlife had brains that were an average of 2.9% smaller, with hippocampi (a region of the brain that plays a crucial role in memory) an average of 4% smaller. “When your hippocampus begins to shrink, you begin to lose your long-term memory and your ability to remember recent events,” said lead study author Rosebud O. Roberts, MB, ChB. People who had developed diabetes during middle age were also twice as likely to have thinking or memory problems and were 85% more likely to have had a ministroke.

Developing diabetes after the age of 64 did not appear to impact the brain, suggesting that the negative effects of the condition on memory and other mental functions takes decades to occur.

“If you have Type 2 diabetes, you have an increased risk of brain damage,” noted Roberts, but if you control your diabetes well, it should reduce the damage that is being caused in your brain.”

People who had developed high blood pressure in middle age were twice as likely as those without the condition to have stroke-caused damage to portions of the brain linked with thought, memory, and language. Developing high blood pressure later in life did not seem to have any negative effects on the brain.

The results of the study emphasize the importance of adopting a healthful lifestyle in middle age or earlier, noted Keith Fargo, director of scientific programs and outreach for the Alzheimer’s Association.

For more information, read the article “Diabetes in Midlife Shrinks the Brain” or see the study’s abstract in the journal Neurology. To learn more about nutritional approaches that may — or may not — work to improve brain function, read the threepart series “Boosting Brain Health: Do Supplements Really Help?” And for brain games that can improve your memory, problem-solving, and language skills, see this resource from AARP.

Learn more about the health and medical experts who who provide you with the cutting-edge resources, tools, news, and more on Diabetes Self-Management.
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  • calgarydiabetic

    One wonders if statins have anything to do with this ?

  • meredith

    All well and good, but it doesn’t affect me…EXCEPT for the fact that my brain is losing control and I wonder what kind of effect it’s going to have on the remainder of my years.

  • Keith

    This doesn’t seem to take into account that when we reach our 60’s and above the brain shrinks. About 2 to 5%. So, is the shrinkage they are referring to actually caused by diabetes or is it the normal shrinkage that most people undergo later in life?

  • brian thomas

    so How does it affect Type 1 memories please?

  • Laura

    Agree with Brian. Very curious to know what implications are for Type 1.

  • Virginia

    I agree with Keith…when my husband, at age 84, was hospitalized with subdural hematomas, the neurological report stated that he had normal brain shrinkage for his age. The neurosurgeon confirmed that this is what happens to a person’s brain as the individual ages. Sigh!!!

  • Tom

    Also would like to know what Type 1 can do to memory. Suspect that tight control – with more “lows” experienced – will diminish some parts of the brain. But which parts? And is the brain permanently damaged by occasional blood sugars in the 50s 60s and 70s? Or is most of the damage done during those rare severe insulin reaction when you lose consciousness? I’ve been on insulin for nearly 40 years and have normal A1Cs. I’m very curious.

  • Jerry Orebaugh

    I’ve had type 1 diabetes for 53 years and my memory and thinking skills have affected me bad. I feel like a dummy. Is there a way to reverse this?

  • Diana

    I too would like to know if it applies to Type 1memories

  • MaryEllen

    This is really interesting. I was diagnosed with type 2 diabetes in 2009 I think. I haven’t had the best if luck trying to keep it under control. I was 56 at the time and this past June I was put on insulin 4 times a day and still have some problems with control. I was also diagnosed with Hepatitis, and I have rheumatoid arthritis.
    I have been very upset cause my memory and focus have changed so much; I can’t think; can’t remember words? I was told by three doctors to see a neurologist. Can they possible be able to help me?
    I am on a lot of medications.

  • Bruce

    Many current articles written about diabetes frequently refer to the complications of Type-2 and make little or no reference to Type-1. I find this disturbing. Like many of the above writers, I also have sensed moments of memory loss and I do the best I can to control my condition. Exercise and getting proper rest is critical. I have tried “Lumosity” and over time have seen improved results with memory and thinking. I’m still not happy with the abundance of Type-2 Only articles.

  • Gillie

    This is terrifying to me.

  • Diane Fennell

    Hi everyone,

    Thank you for your comments. The research referenced in the story above only looked at people with Type 2 diabetes, so it could not draw any conclusions about people with Type 1. However, other studies have indicated that Type 1 diabetes can have effects on various mental functions as well. Please see the links below for some examples:




    Diane Fennell
    Web Editor

  • Jason L. Hargrove,Sr.

    Have memory issues that are related to seizures from low glucose levels in the past. Have tried to get my dr’s to see if there is a link, have always been told no…. Have also asked about other memory medications (Exelon patch). Have been told that my issues are not bad enough for other medications at this time.

  • Blossom Grimm

    recently, my younger brother and I have been having big disagreements and I can’t seem to remember all that he tells me to do, regarding a financial matter.. He yells at me and I cry a lot. I am 78 and diabetic for many years,, he is 72 and very smart and not diabetic. Diabetes runs heavy in our family, grandparents, mother, father, sister, daughter , myself all diabetis ….and some lost limbs etc. It is very painful to remember. This yelling from younger brother gets me very upset and I have A fib, and was told to stay calm. I was told by cardeologist to stay calm, and I take medication for same. I plan on showing this article to my younger brother. Tthank u for the information, I thought I was losing my mind

    thank u blossom

  • Charyl

    Great; ADD, Fibromyalgia Fog, Menopause, and now this! If I lose my phone, and my GPS breaks I’m really screwed!

  • Pat B.

    Oh great, I always thought I was crazy, now I know it!!

  • JohnC

    Certainly would be no surprise of memory issues with poor blood sugar control over several years…as it causes many things to go wrong. Would be surprised if there was a ‘magic pill’ that made the situation any better though. Wouldn’t be surprised either if some of the medications taken were part of the blame.