7/27/11 Quercetin, Resveratrol, Epigallocatechin-3-gallate, Curcumin and Docetaxol
July 27, 2011 It is becoming clear that many natural substances potentiate available chemotherapy drugs and make them either 1) more effective at currently recommended doses or 2) make them as effective as currently recommended doses with a fraction of the recommended dose.
However some of these substances seem to have a negative effect even though they have been shown to be anticancer agents themselves. Quercetin might have an adverse effect on docetaxol for example:
A similar result was shown for resveratrol and taxol although pretreatment with resveratrol had the reverse effect and potentiated taxol.
n-acytlcysteine was shown to “rescued docetaxel-induced cell death” in prostate cancer therapy:
One overview of many studies was done in 2007, Impact of antioxidant supplementation on chemotherapeutic efficacy: A systematic review of the evidence from randomized controlled trials
almost five years ago, and found “None of the trials reported evidence of significant decreases in efficacy from antioxidant supplementation during chemotherapy. Many of the studies indicated that antioxidant supplementation resulted in either increased survival times, increased tumor responses, or both, as well as fewer toxicities than controls; however, lack of adequate statistical power was a consistent limitation. Large, well-designed studies of antioxidant supplementation concurrent with chemotherapy are warranted.”
None of these studies were done with humans, except for the Curcumin-Taxol study which was Phase I, or even mice. They are all cell studies. Therefore nothing can be inferred with certainty.
It seems clear that human studies have not been done because natural substances cannot be patented and testing costs cannot be recouped by drug companies. At the very least affordable mouse studies should be done because millions of people take chemotherapy drugs and hundreds of thousands take supplements during chemotherapy.
Most oncologists do not make recommendations based on cell studies and it isn’t clear that they should make warnings based on cell studies either. The dismal results of twenty years of testing chemotherapy drugs on cells outside the body should have taught us that.
As late as 2011 we have a clinical study sponsored by Northwestern University entitled: Alpha-lipoic Acid in Patients at Risk for Paclitaxel Induced Neuropathy
This trial should have been done at least five years ago. The same can be said for other substances listed here and others not listed such as vitamin C and A.