Green tea and chemotherapy: caution

February 5, 2009 – Taking green tea, brewed or as a supplement, would be contraindicated for people receiving chemotherapy with the bone marrow cancer drug Velcade – also called multiple myeloma.

This discovery surprised the researchers who published their results in the American journal Blood¹. While they were checking to see if the antioxidant components in green tea could amplify the effect of the drug during treatment, they found that they caused the opposite effect instead.

The researchers expected that the antioxidants in green tea – from the polyphenol family – would support the drug. Studies have already shown that polyphenols fought cancer cells in tests on animals with different cancers, including leukemia.

But in experiments conducted first on cancer cells, then on mice with multiple myeloma², the polyphenols instead protected the cancer cells from the effect that the active substance in Velcade, bortezomib, should have caused.

No tea during chemo

According to pharmacist Jean-Yves Dionne, this “good quality” study confirms that caution must be exercised when being treated for cancer.

“During chemo, you have to put aside natural products, including green tea: you can take them up to a certain time before and then after the treatments, but not at the same time,” he recommends.

A specialist in natural products, Jean-Yves Dionne believes that if antioxidants and oncological treatments are “not incompatible”, caution remains however in order. “There is a lot of unknown about the possible interactions and if you can combine it, it should not be done at the same time: when you receive the instillations in the hospital, it is not the time to take antioxidant supplements, ”he suggests.

In addition, the pharmacist considers that green tea remains a drink with multiple protective effects against several diseases.

A serious illness
Multiple myeloma is a serious cancer that attacks certain cells in the bone marrow. In Canada in 2008, there were 2,100 new cases of this cancer, while 1,350 people died from it. The five-year survival rate after being diagnosed with multiple myeloma is estimated to be around 35%³.

Martin LaSalle – PasseportSanté.net

1. Golden EB, Schonthal AH, et al, Green tea polyphenols block the anticancer effects of bortezomib and other boronic acid-based proteasome inhibitors, Blood, pre-published online February 3, 2009; DOI 10.1182 / blood-2008-07-171389
2. For more information on multiple myeloma: www.cancer.ca.
3. Canadian Cancer Society, National Cancer Institute of Canada, et al, Canadian Cancer Statistics 2008. To access the PDF document, click here.