A new study begins to shed light on the surprising link between high blood sugar, diabetes and brain cancers. Past studies have found that brain cancers such as glioma are less likely in people with diabetes and high blood sugar. Could it be, the researchers ask, that brain tumors have a strong effect on blood glucose levels?The researchers – including members from Ohio State University (OSU) in Columbus – report their findings in the journal Scientific Reports. This new study examines data from two large long-term investigations: AMORIS and Me-Can, which together totaled 797,945 participants among whom 812 developed gliomas. Glioma is one of the most common cancers that arise in the brain. It accounts for nearly a quarter of all primary brain tumors and three quarters of all malignant tumors. The team analyzed the data on blood sugar levels and diabetes – including that related to the period preceding diagnosis – and how this related to subsequent diagnosis of glioma. The results showed that participants with high blood sugar and diabetes were less likely to develop glioma. Also, the link was strongest in the year leading up to the diagnosis.