Top News

Here’s how a cup of green tea might help.

Reviewed by Dietitian Lisa Valente, M.S., RD

Key Points

• Green tea has compounds that may help reduce cancer risk.
• Its antioxidants may protect cells, reduce inflammation and change the way cells grow.
• Drinking green tea isn’t a magical cure-all, and more research is still needed.

No single tea can prevent cancer or guarantee a lower risk. Still, tea can be a nutritious addition to an overall healthy eating pattern. “Tea contains a number of plant compounds that have antioxidant and anti-inflammatory properties, and some studies have found an association between tea consumption and a lower risk of certain cancers,” says Amar Rewari, MD, chief of radiation oncology at Luminis Health. “However, the human evidence is inconsistent, and we cannot say that drinking tea by itself prevents cancer,” he cautions.

While all teas contain beneficial plant compounds that may help protect cells from damage, green tea stands out for its high polyphenol content and the amount of research examining its relationship with cancer. However, research findings are mixed, and much of it has been conducted in animals or with concentrated green tea extracts, which aren’t the same as drinking a brewed cup. Adding a cup or two of green tea to your routine probably won’t dramatically change your cancer risk on its own, but it can be a healthy beverage choice. Here’s what experts say about the possible association between green tea and cancer risk.

It May Help Protect Cells from Damage

Polyphenols in tea can act as antioxidants, helping neutralize free radicals and limit the buildup of reactive oxygen species that can damage cells, notes Ginger Hultin, DCN, RDN, CSO. “Over time, accumulated DNA damage can contribute to the development of cancer,” adds Rewari. By helping reduce oxidative stress and the cellular damage it can cause, tea polyphenols may theoretically help protect against some of the changes that contribute to cancer development.

Green tea is particularly rich in antioxidants called catechins, including epigallocatechin gallate (EGCG), its most widely studied catechin. Preliminary research suggests EGCG can help quench reactive oxygen species and influence antioxidant defenses, potentially helping protect DNA and other cellular components from damage. EGCG has also been studied for its effects on other processes involved in cancer development, but these findings still don’t prove that drinking green tea prevents cancer.

It May Help Reduce Inflammation

“EGCG has been shown experimentally to influence inflammatory signaling pathways,” says Rewari. “Chronic inflammation can create an environment that favors cellular damage and cancer development,” he adds. Persistent levels of inflammation over time can promote oxidative stress, DNA damage and signals that encourage the survival and growth of abnormal cells. Laboratory research suggests that EGCG may influence some of these processes by suppressing inflammatory pathways and reducing the production of inflammatory molecules. By helping to keep inflammatory signaling in check, EGCG could theoretically create an environment less favorable for cancer development and progression. Still, more research is needed to ascertain whether drinking green tea produces meaningful anti-inflammatory effects that translate to lower cancer risk.

It May Interfere with Cell Growth

Green tea catechins may influence cell proliferation, or the process through which cells grow and multiply. Uncontrolled cell division is one of the defining characteristics of cancer, so slowing cell proliferation may help prevent the development or progression of cancerous cells. Furthermore, “Laboratory studies suggest EGCG can affect signaling pathways that regulate how cells divide and can promote apoptosis, the process the body uses to eliminate damaged or abnormal cells,” explains Rewari.

EGCG may also influence angiogenesis, the formation of new blood vessels that deliver oxygen and nutrients to tumors as they grow. “Some studies suggest that EGCG suppresses the formation of new blood vessels, helping to reduce or stop the blood supply to cancerous cells,” explains Hultin. Together, these effects could make it more difficult for cancer cells to multiply and tumor cells to grow. More research is needed to determine whether regularly drinking green tea produces these same effects in humans to influence cancer risk meaningfully.

Other Tips for a Cancer Prevention Diet & Lifestyle

• Get moving. Regular physical activity is associated with a reduced risk of certain cancers. Exercise may help lower cancer risk by reducing chronic inflammation, improving insulin sensitivity and supporting immune function. Physical activity also helps strengthen the body’s antioxidant defenses. Aim for at least 150 minutes of moderate-intensity aerobic exercise and two strength-training sessions per week.
• Focus on a healthy, balanced diet. “A diet rich in whole grains, vegetables, fruit and beans/lentils has been shown to help [lower cancer risk],” says Hultin. Try adding one additional colorfulfruit or vegetable to your routine, make one day a week meatless, or replace half of the meat in a dish with beans or lentils.
• Steer clear of supplements for cancer prevention. The American Institute for Cancer Research recommends avoiding any supplements marketed for preventing cancer, as these products have not been shown to prevent cancer or improve cancer outcomes.
• Reduce processed meat intake. Eating more processed meats, like bacon and sausage, is associated with a greater risk of several cancers. Processing, preserving and high-temperature cooking can produce or introduce potentially carcinogenic compounds that may contribute to DNA damage and mutations. Limiting processed meats is a key recommendation from the American Institute for Cancer Research to help lower your cancer risk.

Our Expert Take

Drinking green tea is not a proven way to prevent cancer, cautions Rewari, nor is it necessarily superior to other teas. While its catechins have antioxidant and anti-inflammatory properties and may influence cell growth, human evidence remains inconsistent. Instead, “Think of [green tea] as one potentially healthy component of an overall dietary pattern rather than a cancer-prevention mechanism,” Rewari says. For reducing cancer risk, focus on your overall lifestyle: Stay physically active; eat plenty of whole grains, fruits, vegetables, beans and lentils; limit processed meats; and avoid relying on supplements marketed for cancer prevention.