Metabolic diseases such as high blood sugar levels and diabetes adversely impact a person’s life. But, recent studies have shown that the presence of a high blood sugar level and diabetes may actually offer protection against a specific type of cancer called glioma.
A new research has shown that people with high blood sugar levels are at a lesser risk of developing cancerous brain tumors called gliomas. This study from The Ohio State University may throw more light on how cancerous growths can develop.1
What Is Glioma?
Glioma is a very common type of cancerous tumors that originate in the brain. It develops in the cells that surround the nerve cells and enables them to function. Glioma is usually diagnosed during a person’s middle age. Patients diagnosed with the most common adult form of this tumor, glioblastoma, usually survive for about 14 months. Symptoms usually occur only three months before diagnosis. Currently, no available treatment ensures the patient’s long-term survival and researchers are studying several potential options.2
Who Is At Risk?
Most cancers are usually more prevalent in people with diabetes. Diabetes and elevated blood sugar increase the risk of cancer in many parts of the body including the colon, breast, and bladder.
Earlier research conducted by The Ohio State University concluded that high blood sugar appeared to lower a person’s risk of developing a non-cancerous brain tumor called meningioma. Both studies were led by an associate professor of epidemiology and a researcher in Ohio State’s Comprehensive Cancer Center. The new glioma study also appears in the Scientific Reports journal. But in this case, these rare malignant brain tumors are more prevalent in people with normal levels of blood glucose than those with high blood sugar or diabetes.
How Does High Blood Sugar And Diabetes Reduce The Risk?
Researchers analyzed blood sugar and diabetes data and its relationship to the subsequent development of brain cancer. They observed that people with a high blood sugar level and diabetes had a reduced risk of developing glioma. An insulin-like growth factor is associated with glioma recurrence and is found in reduced levels in people who have diabetes than those who don’t have the disease.
Adverse effects of high blood sugar and diabetes that may paradoxically reduce glioma risk include diabetes-related reduction of bioavailable testosterone levels.
Hyperglycaemia induces apoptosis (death of the cells) and suppresses the progression of neural stem cells.3 Since the glioblastoma stem cells are related to neural stem cells, hyperglycemia may offer protection against glioblastoma. Another potential mechanism is inhibition of cerebral circulation associated with diabetes, which may also reduce glioma risk.4 These proposed mechanisms may work together or separately.
How Does It Work?
Generally, cancer cells need more glucose than non-proliferating cells require. Researchers suggest that increased consumption of blood glucose by the pre-clinical tumor may be responsible for the apparent reduction in glioma risk among people with diabetes or high blood glucose levels. Cancer cells produce energy using aerobic glycolysis5 rather than oxidative phosphorylation used by non-proliferating cells.
What Were The Findings Of The Studies?
The Scientific Reports paper included data collected from two large long-term studies. One study called AMORIS included 5,28,580 Swedes. The second study named Me-Can comprised 2,69,365 Austrians and Swedes. Totally, 812 participants developed gliomas. More importantly, this study evaluated time and age interactions and competing risks, which were not examined in the previous studies.
The researchers evaluated blood sugar levels and diabetes data and its relationship to the subsequent development of brain cancer and found that people with increased blood sugar and diabetes had a lower risk of developing glioma.
This may be because the tumor itself affects blood glucose levels or that high blood sugar or diabetes may paradoxically be associated with a protective factor that lowers the risk of brain tumor.
Though high sugar levels and diabetes are usually related to the development of other ailments, this is a one-off case where these conditions seem to reduce the risk of developing cancerous tumors in the brain. Many studies and research on restrictive diets and their effects on brain cancer development have given mixed results and more research is needed to ascertain if the blood sugar level and brain tumor relationship can be beneficial to brain cancer patients.
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