Camellia sinensis, or green tea contains bioactive compounds (nutraceuticals) referred to as catechins with the most prevalent being epigallocatechin-3-gallate, or EGCG. Various studies suggest that EGCG is associated with beneficial effects in prevention of cardiovascular diseases such as atherosclerosis and coronary heart disease, stroke, type II diabetes, reduced low-density lipoproteins and total cholesterol, reduced bone loss, reduced age related neuro-degeneration, suppressing muscle oxidative stress and inflammation, hastening recovery of physical performance and increased fat metabolism and a variety of other health related benefits such as protection against chemical exposure and radiation.

There is also substantial evidence that EGCG and the other catechins found in green tea can affect and regulate many cancer related genes and molecular pathways.

If you have cancer or are concerned about getting cancer, then the following studies could change your life!


The following association studies have shown how regular green tea consumption results in a reduced risk of various cancers.

  • Consumption of green tea was associated with a 62% reduced risk of Multiple Myeloma (OR=0.38, 95% CI: 0.27-0.53).
  • In women, regular green tea consumption was associated with 32% reduction of pancreatic cancer risk (OR 0.68, 95% CI 0.48-0.96).
  • Consumption of green tea was associated with a 19% reduced risk of bladder cancer in people at risk for the disease (OR = 0.814, 95% CI 0.678-0.976).
  • Consumption of green tea was associated with a 36% reduced risk of esophageal cancer (OR = 0.64; 95% CI: 0.44, 0.95).


The following interventional studies have shown how green tea can be used as a significant component of cancer treatment.

  • In a recent phase II clinical trial on people with early stage chronic lymphocytic leukemia (CLL), daily oral EGCG (2000mg twice daily) resulted in the durable declines in measures of disease progression. In this study, 31% of patients had more than a 20% reduction in their absolute lymphocyte counts (ALC) and 69% of patients had a 50% or greater combined reduction in the size of their lymph nodes.
  • Regulatory T cells (Tregs) are considered to be key immunomodulatory cells of the immune system and are increased in chronic lymphocytic leukemia (CLL). In this clinical trial on people with early stage CLL, 80% of the patients had a reduction of lymphocytosis (high lymphocyte count) and absolute numbers of circulating Tregs and only 10% of the patients required chemotherapy directly after the trial. Furthermore, IL-10 and TGFB serum levels (cancer markers) declined throughout the green tea intake period, in both patients and controls. In this trial, green tea consumption resulted in the control of lymphocytosis as well as in the prevention of disease progression.

EGCG Inhibits Circulating Tumor Cells:

One of the ways that cancer cells metastasize is via the process of angiogenesis, which refers to the process that cancer cells use to recruit their own network of blood vessels for their increased growth needs.

Therefore, by merely having an increased amount of EGCG and catechins in the blood, you go a long way to decreasing the ability of circulating cancer cells to attach to other parts of the body and metastasize.

Furthermore, when we drink green tea versus taking it in supplemental form, we absorb some of the EGCG from our mouth and this EGCG goes directly into the bloodstream, avoiding the metabolic processes of the intestines and liver.

These trials are very important because they show how green tea consumption can not only reduce cancer causing mechanisms in people with cancer, but also how it plays a significant role in PREVENTING CANCERS!

Clinical Studies have indicated that the EGCG and catechins found in green teas can plays a role in regulating cancer causing mechanisms in a variety of cancers including, colon, thyroid, oral, liver, lung, mesothelioma, esophageal, gastric, breast, prostate, nasopharyngeal, bladder, NSCLC, chronic lymphocytic leukemia, head and neck squamous cell carcinoma, pancreatic, endometrial adenocarcinoma, oral squamous cell carcinoma and osteosarcoma.


One of the biggest hurdles of using EGCG for cancer treatment and prevention is that there are many different strains of green teas and they all do not contain the same amount of the cancer-fighting ingredient, EGCG.

You want to only use a strain and brand of green tea that has been tested for its EGCG content. This diagram shows you the EGCG content based on percentage of dried leaf weight of various green teas.

Sencha Uchiyama has over 5% EGCG content

Drinking 6 cups of Sencha-Uchiyama steeped for 10 mins results in an equivalent amount of EGCG (~1.35mg) as drinking 69 cups of Pou Chong or Tikuan Yin green tea steeped for 2 mins!


Bioavailability of Green Tea:

Before we discuss how to use green tea, we need to understand its biovailability, which is an important issue in utilizing its benefits. Recall that in order for a nutraceutical to have cancer fighting activity, it needs to reach the tumor at a level known to affect the specific type of cancer. This is referred to as bioavailability.

  • EGCG absorption takes places mostly in the small intestine, after which it then passes to the large intestine where it is broken down by the action of colonic microflora
  • After being absorbed by the intestine, EGCG is transported to the liver where the cytosolic catechol-O-methyltransferase enzyme attaches a methyl group to it in order to target it for excretion and to decrease its solubility in water. Since the amount of this enzyme varies between people, so does  EGCG bioavailability.
  • Once it is methylated, EGCG undergoes glucuronidation, and sulfation (attachement of more biomolecules). Sulfation/glucuronidation of the methylated product is usually needed for the effective elimination of the methylated product from the body.
  • Therefore, a minimal amount of EGCG reaches the blood stream in its pure form.

However, while EGCG may have the strongest cancer fighting activity of the catechins, the other catechins (EGC, ECG and EC) also have cancer fighting activity and even EGCG that has undergone methylation, glucuronidation, and sulfation, has some cancer-fighting activity. Furthermore, a component of blood (human serum albumin), contributes to the transport and stabilization of EGCG by directly preventing further breakdown by oxidation.

Improving EGCG Bioavailability:

  • Avoid air and store in a cool dark place.
  • Take on an empty stomach at least 30mins before a meal.
  • Longer steeping times increase amount of EGCG released. Steep for 10mins.
  • Hard water that contains calcium, magnesium and other metals can inhibit EGCG absorption.
  • Sucrolose, Xylitol enhance absorption in the digestive tract.
  • 200mg Vitamin C increases bioavailability significantly by preventing EGCG degradation via oxidation.
  • 1000mg of omega-3 (from salmon oil) increases bioavailability significantly
  • Piperene, a component of black pepper also increases bioavailability.


IMPORTANT NOTICE: The information on this page has not been approved by the FDA and all information on this page is for educational purposes only and not intended to treat or cure any diseases. Please consult your doctor before taking this or any form supplements as potentially harmful contraindications can occur with prescription medications.