According to a study published in Science Translational Medicine, the presence of antioxidants in type 2 diabetes medications may promote the spread of cancerous cells. Antioxidants are an important part of disease prevention. They help neutralize harmful molecules known as free radicals, which cause damage to a cell’s DNA. Antioxidants occur naturally in fruits and vegetables. The new study, however, suggests that man-made antioxidants in diabetes drugs protect cancer cells rather than healthy ones.
Antioxidants can be synthesized and placed into certain man-made treatments, such as diabetes drugs. Patients with diabetes are thought to be at increased risk for cancer caused by oxidative stress. Medical Daily reports that, despite the protective properties of antioxidants, they are linked to poorer cancer outcomes. Study author Shicang Yu told Medical Daily, “The administration of drugs with antioxidant activity in cancer patients, such as diabetic patients with cancer, should be carefully evaluated,”
“Accumulating epidemiological evidence suggests that diabetes increases the risk of multiple cancers, including colon, liver, and breast cancers,” the authors wrote. “Therefore, the increased prevalence of diabetes suggests that the incidence of individuals with both diabetes and cancer is also rising.”
The study looked at how two classes of diabetes drugs with antioxidant properties affected mice with colon and liver cancer. The medications were not associated with an increased risk of cancer itself, but it was linked to a higher chance of cancer metastasizing. Apparently, the antioxidants in the drugs are protecting cancer cells rather than healthy ones. Being protected from oxidative stress allows cancer cells to migrate and spread.
The researchers investigated further by conducting cell experiments showing that the diabetes drugs activated the NRF2 signaling pathway, which regulates the expression of antioxidant proteins. Activating this pathway also triggered the expression of proteins that promote metastasis. The researchers said these findings suggest that blocking the NRF2 pathway could prevent the spread of cancerous cells. They also analyzed 176 tumor samples from humans, and found that metastasis was correlated to NRF2 expression. “Our findings indicate that antioxidants that activate NRF2 signaling should be administered with caution in cancer patients,” the authors concluded.