What you may have heard
Some people claim that frequently drinking green tea can prevent cancer.
What the science tells us
Green tea is often seen as a healthy beverage because it contains antioxidants and has anti-inflammatory effects. While animal studies suggest that compounds in green tea may slow the growth of cancer cells, epidemiological research has not shown clear or consistent results. At this time, there is no strong evidence that green tea can prevent cancer in humans.
Epidemiological Evidence
Limited epidemiological research has examined the link between green tea consumption and cancer risk. Existing findings are mixed and inconclusive. More high-quality, large-scale randomized controlled trials (studies that randomly assign participants to different groups to test an effect) are needed to better understand this relationship.
Laboratory Evidence/Supporting Evidence
Animal studies have shown some evidence of cancer-preventive properties from natural compounds in green tea called polyphenols, especially epigallocatechin-3-gallate (EGCG). These compounds may help inhibit cancer cell growth and trigger cell death (Yang et al.). However, their mechanisms are not fully understood, and scientists recommend further research to investigate the potential preventive effects of green tea.
How to reduce your risk
Although green tea is not proven to protect against cancer, you can lower your overall risk by maintaining a healthy lifestyle through eating well, staying active, and following recommended cancer screening guidelines.
Bottom line
Findings from animal studies do not necessarily apply to people, and there is currently no evidence that green tea prevents cancer in humans. While it may offer general health benefits from antioxidant and anti-inflammatory properties, green tea should not be relied on for cancer prevention.