A growing body of research indicates that diabetes can take as devastating a toll on the brain as it takes on the body.
Now, a new study published this week in the journal Neurology shows that people with type 2 diabetes demonstrate a decline in cognitive skills and ability to perform daily activities over the course of only two years.
These changes are linked with an impaired ability to regulate blood flow in the brain, due in part to inflammation, which is a common component of type 2 diabetes.
Normally, the brain distributes blood as needed to areas of increased neural activity. In diabetic individuals, however, this process becomes impaired.
“Normal blood flow regulation allows the brain to redistribute blood to areas of the brain that have increased activity while performing certain tasks,” study author Vera Novak, MD, PhD, of Harvard Medical School in Boston, said in a statement. “People with type 2 diabetes have impaired blood flow regulation. Our results suggest that diabetes and high blood sugar impose a chronic negative effect on cognitive and decision-making skills.”
For the study, the researchers recruited 65 men and women with an average age of 66, half of whom had Type 2 diabetes and half of whom did not. The participants were given a series of memory and cognition tests at the outset of the study and again two years later. They also received brain scans to measure brain volume and blood flow and blood tests to measure inflammation and blood sugar control.
Here are some of the key findings:
- After two years, the people with diabetes showed greater declines in gray matter as well as impairments in their ability to regulate blood flow in the brain than the people without.
- Blood flow regulation decreased by an average of 65 percent in the participants with diabetes.
- Among participants with diabetes, scores on thinking and memory tests decreased by an average of 12 percent, from 46 to 41 points, while test scores of the participants without diabetes stayed the same at 55 percent.
- Higher levels of inflammation were correlated with greater difficulties with blood flow regulation.
- Those with the highest levels of blood flow regulation impairment at the outset of the study had more difficulties performing daily activities (such as cooking and bathing) after two years.
The study is the latest to observe a link between diabetes and cognitive decline. With a growing body of research showing an association between insulin resistance and neurodegeneration, some scientists are even referring to Alzheimer’s Disease as “Type 3 diabetes.”
Hopefully, these findings will one day be used to devise better treatments for the degeneration of thinking and memory skills co-occurring with diabetes. A new trial by Dr. Novak’s team is currently underway to determine whether injecting insulin into the brain might slow cognitive decline.
But for now, better detection and monitoring of blood flow regulation could help predict and manage cognitive challenges in people with diabetes. And even for those without the disease, limiting sugar consumption could prevent or delay cognitive decline caused by neuroinflammation.