Cancer-Fighting Impact of Black Tea

Preclinical data show that black tea theaflavins block cancer development and progression. Human studies are urgently needed to evaluate these findings in the clinical setting.

Scientifically reviewed by: Dr. Gary Gonzalez, MD, in November 2022. Written by: Bruce Edwards.

It has been observed that people with higher intake of black tea have reduced rates of cancers.1

That may be due to a compound found in black tea called theaflavins.

In cell culture and animal models, theaflavins have demonstrated anti-cancer effects, working in multiple ways to slow the spread and progression of many types of cancer.1-5

One group of scientists has dubbed black tea “the future panacea for cancer.”2

Systemic Effects of Theaflavins

When green tea leaves are fermented to make black tea, compounds called theaflavins are formed.6

These black tea polyphenols (theaflavins) have shown body-wide health benefits.

In particular, research has uncovered specific ways that theaflavins play a role in fighting cancer.

By interacting with cellular pathways and processes critical to cancer development and progression, theaflavins beat back cancer cells and make it hard for them to survive and spread.

One review paper noted that an ideal cancer therapy would: 2

  • Shrink tumors by inducing cancer cell death, blocking the growth of new blood vessels in tumors, and slowing or stopping the spread of cancer in the body,
  • Boost immune system function to aid in the fight against cancer, and
  • Reduce the systemic toxic effects that cancer creates.

These scientists believe that black tea theaflavins accomplish all these actions. Several reviews of the anti-cancer actions of theaflavins provide evidence to support this belief. 1-5

A “Guardian Angel” Against Cancer

A gene is critically involved in halting the progress of a wide range of human cancers.

Known as p53, this gene has long been recognized as a tumor suppressor, inhibiting both the formation and progression of tumors. In fact, p53 has earned the nickname “the guardian of the genome.7,8

Tumor suppressor genes are parts of the genetic code that prevent and interrupt malignant changes in cells.

In approximately half of all human malignancies, the p53 gene is mutated, thus impairing the cell protective role of p53.9

When p53 is functional, it defends the health of cells by repairing damage to DNA that can cause mutations that contribute to cancer.9

The p53 gene also acts as a master regulator of cell pathways that are involved in cancer development. Active p53 helps starve cancer cells of fuel, prevent new blood vessel formation, halt spread and metastasis, block cancer cell proliferation, and induce cancer cell death.3

It even helps improve the success of chemotherapy and radiation in attacking existing cancer cells.

In many tumors, however, p53 is mutated. This is a driver of cancer risk and progression.3

Research on theaflavins suggests the activation of p53 as an important mechanism in inducing many of its anti-cancer actions.3

Additional Anti-Cancer Action

Theaflavins regulate a protein called mTOR, which can cause cells to excessively propagate.

Theaflavins also inhibit an inflammation-inducing complex called NF-kB that is involved in cancer development and progression.1,4,7,10

In cell cultures and animal models, theaflavins have demonstrated the ability to impair cancer by:1-5

  1. Reducing the initial development of cancers,
  2. Arresting the cancer cell cycle, halting cancer cells’ ability to grow and proliferate,
  3. Reducing cancer cell viability, making them less robust and resilient,
  4. Inducing the death of cancer cells,
  5. Inhibiting the formation of new blood vessels in the tumor, starving the cancer of oxygen and nutrients,
  6. Impairing the ability of cancer cells to spread and metastasize, and
  7. Boosting the immune system to join the fight against cancer.

What you need to know

Anti-Cancer Activity of Theaflavins

Theaflavins are nutrients found in black tea. These compounds work in different ways to prevent cancer development, block its ability to grow and spread, and directly kill cancer cells.

These anti-cancer effects of theaflavins have been demonstrated for many forms of cancer in both cell cultures and animal models.

A wealth of pre-clinical data has found that theaflavins offer protection against mechanisms involved in cancer development and progression.11-15

These beneficial actions have been seen in cancers of the breast, prostate, lung, ovaries, cervix, skin, colon, liver, esophagus, stomach, and hematological malignancies like leukemia.1-5

Human Studies

There are human data to support this. One study recruited men with prostate cancer who were scheduled for surgery.16 Some consumed black tea for five days prior to surgery while others received a placebo drink.

After surgery, levels of tea polyphenols were significantly higher in the removed tumor tissues of men who received black tea.

Scientists then attempted to grow the prostate cancer cells in a cell culture containing blood serum from the patients. In these cultures, cancer cell growth was significantly reduced in those who drank black tea five days prior to surgery.


Preclinical studies have found that theaflavins from black tea exert anti-cancer effects.

Cell culture and animal models have demonstrated multiple ways that theaflavins block cancer development and progression, and epidemiological studies show that people with higher intake of black tea theaflavins have reduced rates of cancers.

We hope the data presented in this article will motivate oncology researchers to initiate clinical trials to assess whether adding theaflavins to conventional cancer treatments improves patient outcomes.

Theaflavins Fight Cancer by Some of the Same Mechanisms as Statin Drugs

Recent research has found that some common medications possess anti-cancer activity. For example, the statin drugs used to treat abnormal cholesterol levels have been found in some studies to reduce risk for cancer. This effect is believed to be attributable to various mechanisms including modulation of mTOR and associated PI3K/Akt.

These cellular signaling pathways are intertwined with many other mechanisms of cancer development and progression. Theaflavins have been found to share many of these mechanistic targets.1,4,5,17

Theaflavins are not a substitute for conventional cancer treatment. They may later demonstrate efficacy as an adjuvant nutrient analogous to doctors who recommend vitamin D to patients with diseases like type II diabetes and cancers today.

If you have any questions on the scientific content of this article, please call a Life Extension Wellness Specialist at 1-866-864-3027.


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