Green tea, also known as Chinese tea, contains polyphenols, which researchers conclude has properties to combat or weaken cancer activity. One polyphenol, namely epigallocatechin-3-gallate (EGCG), has proved to hinder numerous processes associated with cell replication, thus causing the death of tumor cells. EGCG can also slow or prevent the formation of blood vessels around tumors.
Research indicates that another polyphenol, epigallocatechin (ECG), can stop leukemic cells from growing and multiplying. Since Green Tea is an antioxidant, it might repair cell damage, but whether it can entirely prevent the risk of developing cancer remains questionable, despite the many clinical and animal studies.
Oral Cancer: The research team led by Joshua Lambert concludes that EGCG can set off mitochondrial damage in tumors and activate programmed cell death. The team experimented by growing Oral Cancer cells and normal cells in Petri dishes and exposed the contents to EGCG. EGCG selectively chose the SIRT3 in Oral Cancer cells and affected its mitochondrial function, whereas it didn't hurt the SIRT3 in healthy cells. In fact, the opposite happened. The researchers noted that EGCG increased the mitochondrial membrane potential in healthy cells, which is required for efficient metabolism.
Leukemia: A scientific study published in the British Journal of Cancer explored whether there are any visible links between the intake of Green Tea and the risk factor of Leukemia by studying 107 adults diagnosed with chronic lymphocytic Leukemia. The results of the case study indicate that Green Tea can reduce the risk of developing leukemia, especially if consumed frequently in higher amounts. EGCG causes caspase-dependent death in chronic lymphocytic Leukemia cells.
Lung Cancer: A 2010 Taiwanese study observed tea drinking and smoking habits of around 500 people, and the researchers learned that those who did not drink Green Tea had a five times higher risk of developing Lung Cancer. Among smokers, the study found that the risk was twelve times higher. Recent research proved that EGCG could raise the levels of mi-R210 in Lung Cancer cells. Cells with higher levels of mi-R210 multiplied with less agility than Lung Cancer cells with lower levels of mi-R210. Additionally, Lung Cancer cells with higher levels of mi-R210 lost the ability to grow atop each other, thus curbing the severity of cancer.
Ovarian Cancer: A case-controlled study conducted in China during 1999 and 2000 discovered significant dose-response relationships between Green Tea and ovarian cancer, i.e., the increased duration and frequency of Green Tea consumption could reduce the risk of developing Ovarian Cancer.
Prostate Cancer: Susanne M. Henning suggests that men who consumed Green Tea frequently had less prostate tissue inflammation associated with cancer growth when compared to those who didn't drink it. Her team studied 79 men with Prostate Cancer and found that the polyphenols in Green Tea could target prostate tissue and modify the inflammation of the prostate.
Breast cancer: A 2017 research checked the breast density in women who were administered with an EGCG supplement for an entire year. Those with a higher breast density have an increased risk of getting diagnosed with Breast Cancer. Although the EGCG supplement didn't affect the breast density in older women, it caused a significant decrease in breast density in younger women.
Colorectal cancer: The results of the study published in Carcinogenesis points out that Green Tea can stop Colorectal Cancer in its tracks by particularly targeting colon carcinogenesis in its initial stages. However, the EGCG in Green Tea might not be able to affect or inhibit the growth of adenocarcinomas formed before the administration of Green Tea.
Apart from keeping the growth of cancer cells in check, Green Tea can boost the immune system to help fight cancer better. By getting rid of toxins from the body, Green Tea improves energy levels, health, and overall well being of the patient. Frequent consumption of Green Tea can also reduce the side-effects of cancer and its treatment.
So far, the studies conducted to evaluate the benefits of Green Tea for cancer patients and its role in curbing the severity of the disease has delivered promising results. Green Tea has also proven to reduce the risk of cancer and its recurrence.
However, evidence for the role of Green Tea in avoiding a cancer recurrence or preventing it is limited. A meta-analysis performed in 2010 evaluated the benefits of Green Tea and its effect on the incidence and recurrence of Breast Cancer. 12 studies were included, and the results underlined that consuming more than three cups of Green Tea every day has a 27% chance of lowering the risk of Breast Cancer recurrence.
It's advised to avoid Green Tea if you are pregnant or breastfeeding. The caffeine present in the tea can pass into breast milk and cause Insomnia in the nursing infant. Also, Green Tea consumption has an increased risk of miscarriage or inducing congenital disabilities related to folic acid deficiency.
If you have bleeding disorders or anemia, then it's better to stay off green tea, as it can aggravate the symptoms and make your anemia worse.16 Those with peptic ulcers are better off without green tea, as it may stimulate the production of gastric acid and upset the stomach.
Green tea is a safe beverage, but consumption in large amounts can damage the liver and alter liver enzymes.
A laboratory study18 conducted in 2013 proved that EGCG could enhance the action of some anti-cancer medications, but it exacerbated a patient's condition by changing the way other cancer drugs worked.
The severity of cancer differs from one patient to another, and each person may respond to Green Tea differently if it is used as a complementary therapy. Hence, it is vital to get in touch with your cancer center or oncologist to know what'd work better for you.