Green Tea Continues to Uphold Reputation as Killer of Cancer Cells

Green Tea Leaves with Scoop

It may be time to swap your morning coffee for a cup of freshly brewed green tea.

A new study conducted by food scientists at Penn State University shows that green tea’s primary compound — epigallocatechin-3-gallate (EGCG) — may kill oral cancer cells and leave healthy cells unscathed.

Scientists believe that EGCG may trigger a process in the mitochondria of cancer cells that leads to early cell death. EGCG already is known to induce cell death in five mesothelioma cell lines.

“It looks like EGCG causes the formation of reactive oxygen species in cancer cells, which damages the mitochondria, and the mitochondria responds by making more reactive oxygen species,” said Joshua Lambert, associate professor of food science and co-director of Penn State’s Center for Plant and Mushroom Foods for Health.
As mitochondria damage continues, the cancer cell further lowers its defenses, making it susceptible to early cancer death.

Studies show tannins and antioxidants in green tea may help slow or prevent the spread of mesothelioma cancer cells.

Cup of Green Tea

Researchers say EGCG in green tea can kill mesothelioma cancer cells.

Penn State Study Explained

The Penn State group studied cancerous human oral cells and noncancerous human oral cells side by side to determine the effect of EGCG in different stages of the oral cancer development process.

They harvested the cells in Petri dishes and exposed them to EGCG at concentrations typically found in saliva after chewing green-tea gum.

At various times throughout the study, researchers collected the cells and checked for oxidative stress and signs of antioxidant response. They also took several pictures after tinting the cells with fluorescent dyes to measure mitochondrial function and oxidative stress.

Researchers said the SIRT3 protein, also known as sirtuin 3, is critical to the process.

“It plays an important role in mitochondrial function and in anti-oxidant response in lots of tissues in the body, so the idea that EGCG might selectively affect the activity of sirtuin 3 in cancer cells, to turn it off, and in normal cells, to turn it on, is probably applicable in multiple kinds of cancers,” Lambert said.

This study marks the latest research to highlight green tea as a potential cancer fighter.

A 2002 study first revealed the correlation between green tea and oral cancer, but it wasn’t until this 2015 study that scientists figured out why green tea specifically targeted only the cancerous cells.

What’s Next?

Lambert said the next step would be to study the process in animals. If those tests and human trials are successful, researchers hope to create anti-cancer treatments that work just as well as current cancer treatments but lack the harmful side effects.

At the moment, treatment for oral cancer, which kills 8,000 and affects 43,000 Americans annually, is limited to a combination of radiation, chemotherapy and surgery.

While traditional chemotherapy is an effective way to treat cancer, it comes with a slew of negative side effects, such as fever, vomiting and hair loss.

You don’t see these side effects with EGCG in green tea.

“If future human clinical trials are positive,” says Lambert, “I think green tea could be useful in preventing the development of oral cancer, as well as preventing recurrence in people that have had surgical or chemotherapy treatments. I do not think green tea will become a first-line treatment to cure oral cancer patients.”

While green tea offers a multitude of health benefits for non-cancer and cancer patients alike, always consult your doctor to find out if green tea is the best beverage for you.

Other Health Benefits of Green Tea

Green tea has long been hailed for its many health benefits.

The century-old drink is used to increase mental alertness, lower cholesterol levels, assist with weight loss and protect skin from sun damage.

Green tea also is used as a supplement to aid in the prevention and treatment of a variety of cancers, including those of the skin, breast, stomach and lung.

  1. Cancer Cell International. (2013, February 23). EGCG induces human mesothelioma cell death by inducing reactive oxygen species and autophagy. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/23432995
  2. Penn State University. (2015, January 28). Green tea ingredient may target protein to kill oral cancer cells. Retrieved from http://news.psu.edu/story/342487/2015/01/28/research/green-tea-ingredient-may-target-protein-kill-oral-cancer-cells
  3. US National Library of Medicine National Institutes of Health. (2002, March-April). Chemoprevention of oral cancer by green tea. Retrieved from http://www.ncbi.nlm.nih.gov/pubmed/12004708.
  4. National Center for Complementary and Integrative Health. (2012, April). Green tea. Retrieved from https://nccih.nih.gov/health/greentea
  5. The Oral Cancer Foundation. (n.d.). Oral cancer facts. Retrieved from http://www.oralcancerfoundation.org/facts/
  6. Yahoo! Health (2015, January 29). Green tea may zap cancer cells in your mouth. Retrieved from https://www.yahoo.com/beauty/green-tea-may-zap-cancer-cells-in-your-mouth-109500145432.html

Lynette Zilio is a public outreach coordinator for The Mesothelioma Center, where she strives to spread awareness about mesothelioma and the dangers of asbestos exposure. She graduated magna cum laude with a Bachelor of Science degree in online journalism and a minor in Spanish from the University of Florida. She currently is pursuing an online master’s in mass communication and social media at UF. If you have a story idea for Lynette, please email her at lzilio@asbestos.com

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