Essiac Cancer and Health Benefits
Scientific Studies

What do scientific studies say about the widely reported Essiac benefits for cancer and other health issues?

Okay, first let me confess I am biased.

Learning about Essiac Tea has been an incredibly moving experience. The amazing story of Rene Caisse and Dr. Charles Brusch, the unbelievable testimonials of so many cancer patients, all combine to form something of a modern legend.

However, in this article, I am mainly interested in discovering what scientists and researchers think about this herb. So, are you ready to know the truth of the Essiac cancer fighting credential?

Here is a list of the scientific studies that I have managed to dig out. See what you make of it.

Essiac Cancer Studies #1:
Antioxidant. Anti-Inflammatory.

A 2005 study conducted by University of British Columbia investigated the antioxidant and anti-inflammatory properties of Essiac and Flor-Essence herbal teas.

The researchers concluded that both Essiac Tea and Flor-Essence have been found to have the ability to quench free radicals and reduce inflammation. Interestingly, Essiac Tea stimulated the nitric oxide system whereas Flor-Essence did not. This study was reported in Oncology Reports in 2005.

A 2007 study conducted by The Canadian College of Naturopathic Medicine arrived at a similar conclusion. According to researcher Seely D et al., this is the first comprehensive effort to study the cell culture effects of Essiac. Here is their conclusion:

Despite the recommendation of the Task Force on Alternative Therapies of the Canadian Breast Cancer Research Initiative, little research has been published on the widely used herbal compound Essiac.

We aimed to address this deficiency by conducting a series of assays to determine some of the purported activities of Essiac in vitro.

In vitro analysis of Essiac indicates significant antioxidant and immunomodulatory properties, as well as neoplastic cell specific cytotoxicity consistent with the historical properties ascribed to this compound. Importantly, significant CYP450 and fibrinolysis inhibition were also observed.

This is the first comprehensive investigation of the in vitro effects of Essiac.

Essiac Cancer Studies #2:
Reduce Prostate Cancer Risk. Strengthen Immunity

A 2004 study conducted by Indiana University/Purdue University discovered that Essiac Tea may stop prostate cancer cells from multiplying in petri dishes. The study found that Essiac may have a more selective effect on cancer cells than non-cancerous cells, decreasing their ability to multiply.

Researchers Ottenweller and his colleagues concluded:

Essiac preparations may be able to inhibit tumor cell growth while enhancing immune response to antigenic stimulation. This may be especially valuable in immune-suppressed individuals.

This Essiac cancer study was conducted using the Essiac Canada International's herbal product. It is published in the Journal of Alternative & Complementary Medicine.

Essiac Cancer Studies #3:
No Anti-Cancer Effects.

Confusingly, another 2007 study conducted by Prostate Center at Vancouver General Hospital investigated whether commercial Essiac Teas would have anti-cancer and other health effects in cell culture and mice.

They concluded that Essiac has no marked effect in preventing cancer cells from growing.

Another 2006 study conducted by the University of Toronto arrived at the conclusion using laboratory mice. Interestingly, the researchers admitted that little research has been carried out to date:

Essiac is a herbal compound that has been in common use with cancer patients in North America for over 80 years. Despite its relatively widespread use, there are no peer-reviewed published reports of in vivo studies regarding the use of this compound.

Researchers Leonard B.J. et al. then concluded:

Essiac did not demonstrate significant hepatoprotective, hypoglycemic or immunomodulatory properties.

Essiac, administered in established in vivo experimental models, did not significantly demonstrate its purported physiological modifying effects.

Essiac Cancer Studies #4:
Increase Breast Cancer Risk

Flor-Essence is one of the major Essiac Tea brands composed of 8 herbs. It is owned by the Flora Health Company.

A 2004 study conducted at Center of Cancer Research found that rats given a 3% or 6% Flor-Essence solution from birth throughout their lives had a higher incidence of breast tumors than those who received no Flor-Essence.

Rats that consumed the 3% solution had a breast cancer rate of 59%. At the 6% solution, the incidence rate increased to 65%. In contrast, rats that didn't consume Flor-Essence had  a lower breast cancer rate of 51%.

The researchers concluded that Flor-Essence can promote breast cancer in rats.

Similar results were obtained during a 2006 human trial conducted by the Lawrence Livermore National Laboratory at California. The researchers used both Flor-Essence and Essiac Herbal Tonics.

This is what they concluded:

Flor-Essence and Essiac herbal tonics at 1%, 2%, 4% and 8% stimulated cell proliferation relative to untreated controls. Flor-Essence and Essiac Herbal Tonics can stimulate the growth of human breast cancer cells through estrogen receptor .. mechanisms of action.


Although I want to believe, when I dig into the Essiac cancer studies, I have to conclude there is little medical evidence about its anti-cancer and other reported health benefits.

I am not saying we should not drink Essiac. Far from it. This tea is pretty harmless, and its advantages usually far outweigh the risks. The sad truth is that after so many years, much still needs to be done to understand this tea. Researchers Leonard B.J. et al. concluded:

Essiac is a herbal compound that has been in common use with cancer patients in North America for over 80 years. Despite its relatively widespread use, there are no peer-reviewed published reports of in vivo studies regarding the use of this compound.

A team of researchers from The University of Texas-Houston School of Public Health peer reviewed the scientific literature up to the late 1980s and concluded:

A review of the literature ... resulted in 107 references. Of those, 68% [73] were related to cancer. Although 24 pre-clinical evaluations of individual herbs were reported, no pre-clinical or clinical trials of the tonic were identified.

One clinical study with Essiac™ was discontinued by The Health Protection Branch of Health Canada in 1978 because of limited physician participation. Data from 87 participants was considered inadequate to determine any impact on survival.

However, no toxicity was reported, but quality of life or pain control were not evaluated.

The situation we are in now, is that scientists are just beginning to test it systematically!

If Essiac cancer benefit is folklore, how do you explain the countless number of testimonials vouching for its effectiveness? Given its low cost and the lack of side effects, I would consider even a Essiac cancer success rate of 10% to be highly impressive.

The waiting game continues... In the meantime, I think it is fair to say you just have to try it to find out.

To learn more about the reported benefits, and what a survey conducted by Flor-Essence revealed, read Essiac Health Benefits.


Cheung S, Lim KT, Tai J (2005). Antioxidant and anti-inflammatory properties of ESSIAC and Flor-Essence. Oncol Rep 14 (5): 1345-50, 2005.

Seely D, Kennedy DA, Myers SP, Cheras PA, Lin D, Li R, Cattley T, Brent PA, Mills E, Leonard BJ (2007). In vitro analysis of the herbal compound Essiac. Anticancer Res. 2007 Nov-Dec;27(6B):3875-82.

Ottenweller J, Putt K, Blumenthal EJ, Dhawale S, Dhawale SW. Inhibition of prostate cancer-cell proliferation by Essiac (2004). J Altern Complement Med 10 (4): 687-91, 2004.

Eberding A, Madera C, Xie S, Wood CA, Brown PN, Guns ES (2007). Evaluation of the antiproliferative effects of Essiac on in vitro and in vivo models of prostate cancer compared to paclitaxel. Nutr Cancer. 2007;58(2):188-96.

Leonard BJ, Kennedy DA, Cheng FC, Chang KK, Seely D, Mills E (2006). An in vivo analysis of the herbal compound essiac. Anticancer Res. 2006 Jul-Aug;26(4B):3057-63.

Bennett LM, Montgomery JL, Steinberg SM, et al (2004).Flor-Essence herbal tonic does not inhibit mammary tumor development in Sprague Dawley rats. Breast Cancer Res Treat 88 (1): 87-93, 2004.

Kulp KS, Montgomery JL, Nelson DO, Cutter B, Latham ER, Shattuck DL, Klotz DM, Bennett LM (2006). Essiac and Flor-Essence herbal tonics stimulate the in vitro growth of human breast cancer cells. Breast Cancer Res Treat. 2006 Aug;98(3):249-59.

Mary Ann Richardson, Tina Ramirez, Carmen Tamayo, Carrie Perez, J. Lynn Palmer Flor Essence Herbal Tea Blend Use in North America: A Profile of General Consumers & Cancer Patients.

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