The causes of cancer are complex, though DNA damage is a central characteristic.

A high intake of antioxidants, such as flavonoids and proanthocyanidins, are associated with a reduced risk of various cancers (38).

The antioxidant activity of GSE has shown potential to inhibit human breast, lung, gastric, oral squamous cell, liver, prostate, and pancreatic cell lines in lab settings (39, 40, 41, 42).

In animal studies, GSE has been shown to enhance the effect of different types of chemotherapy (43, 44, 45).

GSE appears to protect against oxidative stress and liver toxicity while targeting chemotherapy action on the cancerous cells (46, 47, 48).

A review of 41 animal studies found that either GSE or proanthocyanidins reduced cancer-induced toxicity and damage in all but one of the studies (49).

Be mindful that the anticancer and chemopreventive potential of GSE and its proanthocyanidins may not be directly transferable to people with cancer.