I recently had a patient I was treating for lymphoma, a white blood cell cancer, whose owner was interested in giving the dog Essiac Tea, a well-known herbal remedy sometimes recommended for cancer patients. In order to advise this client, I investigated this remedy, and I want to share the results of that investigation.
What Is It?
Essiac tea contains four plants:
Indian Rhubarb root
There is also a related product, Flor Essence, that contains an additional four ingredients:
The inventor of this concoction claimed it to be a Native American recipe, however there is no evidence this is actually true, and some reason to doubt this story. In any case, the product came into use in the 1920s, and since it has been recommended as a cancer therapy and treatment for many other health problems. It is marketed as a dietary supplement, which means there is no requirement for scientific evidence showing it is safe or effective so long as those selling it don’t make any specific claims that it can prevent or treat disease. This does not stop many people, however, from making numerous claims about health benefits for a wide range of conditions, including the potential to treat or even cure cancer. These claims are made for pets as well as humans.
Does It Work?
The short answer is, “No.” The longer answer is that there is no reason to believe it has any benefits at all based on the limited research that currently exists. It is never possible to completely disprove any possible effects of any chemical compound, even eith extensive clinical testing. However, with no sound biologic rationale and no compelling evidence so far despite miraculous claims made over nearly a century, the chances of any real benefits being yet undiscovered is vanishingly low. Here are the conclusions of a number of existing:
1. Katja Boehm, CAM-Cancer Consortium. Essiac.
“There is no evidence from clinical trials to indicate that it is effective. No clinical trial has been carried out to assess its efficacy and the only published uncontrolled clinical investigation did not suggest that Essiac has an effect on tumour burden.
2. Cancer Research UK- Essiac
“There is no scientific evidence to show that Essiac can treat, prevent or cure cancer or any other serious illness in humans.”
3. National Cancer Institute- Essiac
“There is no evidence reported in peer-reviewed scientific journals to show that the exact formulas of Essiac and Flor Essence are effective in patients with cancer or other health conditions…”
4. Ulbricht C, Weissner W, Hashmi S, Rae Abrams T, Dacey C, Giese N, Hammerness P, Hackman DA, Kim J, Nealon A, Voloshin R. Essiac: systematic review by the natural standard research collaboration. J Soc Integr Oncol. 2009 Spring;7(2):73-80.
“A review of the literature on Essiac and essiac formulations showed a lack of high-quality clinical trials to substantiate any of Essiac’s traditional uses. Weak evidence from preclinical, animal, and laboratory data warranted a discussion regarding Essiac’s use for cancer, but the results are inconclusive. Several other essiac preparations are noted in the literature, adding confusion to the exact formula and its proposed benefits. In general, there is a lack of both safety and efficacy data for Essiac and essiac formulations.”
There are no research studies at all to establish efficacy in dogs and cats.
Is It Safe?
The short answer is, “Who knows?” The limited evidence in lab animals has turned up some potential risks, including actually increasing the risk of cancer. However, the quality of evidence concerning safety is no better than that concerning any benefits. All of the individual ingredients have been reported to have undesirable side effects in humans, though the seriousness of these or the effects of using the individual ingredients together has not been studied. It is important to remember that anything which has any effect at all on the body can potentially have undesirable effects. The lack of good evidence does not mean the product is safe, only that we don’t know whether it is safe or not.
There is no reason to believe Essiac has any benefits for dogs or cats with cancer or any other medical condition. The research evidence is limited, but without a good reason to think there might be benefits, the lack of evidence means no claims of benefits are justified. An absence of evidence, especially given nearly a century of claims for dramatic results, is more consistent with there being no benefit rather than with the product being a powerful treatment. Additional research could possibly show actual benefits in the future, but for now any use of this product is simply rolling the dice with your pet’s health.
Similarly, the evidence does not show whether or not the product is safe. Safety cannot be assumed in the absence of evidence, and it is more appropriate to assume there is some risk until safety is proven. Even individuals with cancer can have their lives made worse by the harm done by untested treatments, so there is currently no justification for inflicting this remedy on dogs and cats.
As usual, I will probably receive numerous anecdotes along the lines of “Well, I tried it and it worked for me/my dog.” I have responded many times in detail as to why these are not useful in evaluating therapies like Essiac, so to save time I will list the articles that address this topic for anyone who thinks anecdotes contribute something to answering the questions of safety and efficacy: