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 three-part 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.