Researchers at the Yale School of Medicine have discovered that insulin nasal spray may improve cognitive function in obese and pre-diabetic adolescents, supporting previous evidence that suggests diabetes drugs could help treat Alzheimer’s symptoms that impact memory and reduce signs of Alzheimer’s in the brain.
While insulin normally helps maintain our blood sugar or metabolism, it can also reach the brain and impact our cognition, mood and appetite. In type 2 diabetes, the body’s cells often become resistant to insulin. When this process happens in the brain, it could cause cognitive impairment and increase dementia risk.
Dr. Dana Small and her team of researchers at Yale’s Modern Diet and Physiology Research Center wanted to better understand whether sending insulin into the brain through the nose could improve cognition in obese teens with pre-diabetes. They discovered that compared to a placebo, obese teens who received the insulin spray did better on a memory task and experienced improved connections between the left and right dorsolateral prefrontal cortex—parts of the brain that impact cognition.
Previous studies illustrate that having a high BMI or diabetes puts people at an increased risk for developing dementia. Although the findings from this study are preliminary, they show that insulin nasal spray could help reduce the impact insulin resistance has on the brain.
Researchers have also started investigating whether insulin nasal spray could benefit people living with Alzheimer’s. Previously, researchers at Wake Forest Baptist Medical Center found that insulin nasal spray could improve memory in people who have mild cognitive impairment and Alzheimer’s disease.
More recently, researchers from Harvard Medical School and the University of Massachusetts conducted a small study that found intranasal insulin may also improve verbal abilities and motor function in people living with Parkinson’s, a condition that has been linked to certain types of dementia.
Small’s findings also support a recent study by researchers at the University of Tübingen that found treating insulin resistance could benefit the brain. The researchers discovered that people with a higher BMI often have insulin resistance in the brain, but exercise can improve sensitivity to insulin.
“The bottom line is that exercise improves brain function,” said lead researcher Dr. Stephanie Kullmann. “And increasing insulin sensitivity in dopamine-related brain regions through exercise may help decrease the risk of a person to develop type 2 diabetes, along with the benefits for mood and cognition.”
Similarly, another recent study looked at male veterans who were over 50 years old and indicated that the drug Metformin, used to treat type two diabetes, can significantly reduce the risk of dementia in African Americans with this type of diabetes.
Some researchers have referred to Alzheimer’s as “type 3 diabetes” because the two diseases have similar characteristics related to insulin resistance and memory function. Future research on the impact of insulin nasal spray and diabetes drugs on memory function may provide researchers with another treatment option for Alzheimer’s symptoms.