Diabetes is a common problem all around the world. In just America alone, more than 24 million people have type 2 diabetes. Diabetes can cause many different complications with different parts of the body. One recent discovery showed that those with higher blood sugar (more than the normal range) may end up with greater chance of brain shrinkage, which also occurs in aging and diseases like dementia.

Study author Nicolas Cherbuin, PhD, with Australian National University in Canberra said, “Numerous studies have shown a link between type 2 diabetes and brain shrinkage and dementia, but we haven’t known much about whether people with blood sugar on the high end of normal experience these same effects.”

This study involved 249 people who were aged 60 to 64. Each participant had a normal range of blood sugar that was defined by the World Health Organization. At the beginning of the study, each participant started with a brain scan and also had a brain scan four years later.

Participants with higher fasting blood sugar ranging from the normal range to below 6.1 mmol/l were more likely to have a loss of a brain volume in areas of the brain, the hippocampus and the amygdale. These areas control memory and cognitive skills. A fasting blood sugar that is considered impaired or pre-diabetic is a level of 6.1 mmol/l and a fasting blood sugar level of 10.0 mmol/l is considered diabetes.

The study looked to different aspects of each participant such as age, high blood pressure, smoking, alcohol used and other aspects. Researchers found that high blood sugar accounted for 6 to 10 percent of brain shrinkage.  Cherbuin said, “These findings suggest that even for people who do not have diabetes, blood sugar levels could have an impact on brain health. More research is needed, but these findings may lead us to re-evaluate the concept of normal blood sugar levels and the definition of diabetes.”