As a general rule, I support the concurrent use of antioxidant-rich foods and food supplements along with anticancer drugs. I have even written a book (Antioxidants Against Cancer) with a section on that topic. There is a considerable amount of documentation on the benefit of doing so and very little indication of harm. However, I am also committed to informing my readers if and when situations arise in which such concurrent usage appears unwise. Such a situation has now arisen.

Velcade (bortezomib) is a drug used in the treatment of multiple myeloma. It is also indicated for the treatment of patients with mantle cell lymphoma who have previously received one other therapy. Velcade is classified as a proteasome inhibitor. Green tea (Camilla sinensis), on the other hand, is a widely used beverage, an unfermented form of the beverage, which many people also take for proposed medicinal purposes. Millions of people drink it with no problem. When I was in China in October it was heartening to see many people from the countryside sipping their thermoses of green tea. It seemed like a healthier alternative to another elixir that is growing in popularity, Coca Cola.

But should green tea – which most people agree is a very healthful beverage – be used when one is also taking Velcade? At first sight, you might think that these two agents would go well together. But when scientists at the University of Southern California (USC) studied the combination they got a shock. An extract of green tea, including its very active ingredient, EGCG, did not enhance the effects of Velcade in either multiple myeloma or brain cancer (glioblastoma) cells. Instead, it effectively prevented tumor cell death induced by Velcade in both test tube and animal studies (Golden 2009).

Essentially, EGCG blocked the proteasome inhibiting effect of Velcade, so that it could not trigger stress in the cancer cell or activate a compound called caspase-7 that was necessary for its action. This negative effect may be limited to Velcade. In this experiment, it was only seen in boronic acid-based proteasome inhibitors but not in the slightly different non-boronic acid based agents (such as the drug Viracept).

The authors conclude: "Green tea polyphenols may have the potential to negate the therapeutic efficacy of bortezomib [i.e. Velcade] and suggest that consumption of green tea products may be contraindicated during cancer therapy with bortezomib" (Golden 2009).

It bears repeating that these were in vitro and in vivo experiments (not human clinical trials). Nonetheless, the results are disturbing. They are also confusing, since researchers at the University of Florida had previously shown that EGCG in green tea was also a proteasome inhibitor (Smith 2002). However, I think that the latest results should be taken seriously. If you are taking Velcade (bortezomib). If you are not taking Velcade there is no indication that green tea or EGCG are anything but healthful.

--Ralph W. Moss, Ph.D.

References:

Golden EB, Lam PY, Kardosh A, Gaffney KJ, Cadenas E, Louie SG, Petasis NA, Chen TC, Schonthal AH. Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors. Blood. 2009 Feb 3. [Epub ahead of print]


Smith DM, Wang Z, Kazi A, Li LH, Chan TH, Dou QP. Synthetic analogs of green tea polyphenols as proteasome inhibitors. Mol Med. 2002;8:382-392.

PHONE CONSULTATIONS

We offer phone consultations for people who have purchased and read our comprehensive Moss Report on their particular condition. The following are the comments of two recent phone consultees:

"Ralph Moss is, perhaps, the best 'cancer coach' that I have spoken to. He is independent and has a wealth of information and experience to draw on, but what makes him truly outstanding is the intellectual integrity of his advice and his ability to formulate highly customized practical recommendations for each individual situation. He is honest about what he knows and what he does not know and clear about the potential benefits as well as about the risks and the unknowns of any treatments that he discusses. I would thoroughly recommend reading the Moss Reports and a consultation with Ralph Moss as the first and most important step in any research of cancer treatments." - E.P., February 18, 2009.

"Very informative. Moss is up to speed on almost all the cutting-edge stuff and frequently knows the researchers and doctors personally. His recommendations were very good for me and I intend to follow up. I really liked his very personable style and the fact that if he did not know something he would say so. I look forward to talking to him again and to getting his opinion if I find something that I do not understand." - L.H., February 19, 2009.

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