High Doses of Antioxidants Including Vitamin C Do Not Decrease the Efficacy of Chemotherapy The idea that the use of antioxidants decreases the efficacy of chemotherapy is being used more and more by orthodox oncologists. It is based upon their hyposthesis that anything which decreases the oxidant effect of drugs will decrease the efficacy of chemotherapy. More and more I hear this from my patients after they are diagnosed and chemotherapy is discussed with them by their oncologists. This opinion is not universal but my guess is that about 75% of oncologists hold this view. The view that chemotherapy destroys tumor tissue because it introduces powerful oxidantion products, free radicals and that anything which decreases that must interfere with treatment. They know they are using sub-lethal amounts of toxic compounds that would never pass FDA standards in any different context. The aim is to kill all the tumor tissue without killing all the other tissues in the body. This is always a close call. Therefore, since vitamin C is a good antioxidant it must not be given with chemotherapy. One of my patients was told by his oncologist that if he took vitamin C he would not be given any chemotherapy. Well, what are the facts? The first fact is that there are no clinical series which show that patients given vitamin C and chemotherapy fare worse than those not given this vitamin. On the contrary, all the published series show just the opposite. I have treated over 1,100 cases with large doses of vitamin C and most of them had chemotherapy.(1-4). I have examined the follow up data and find that the mean difference on prolongation of life was heavily in favor of the use of the vitamins. In the first series I published with Linus Pauling those patients on my program lived 10 to 20 times as long as the patients not r eciving the vitamin. Recently Kedar N. Prasad et al (5) after reviewing 71 scientific papers, found no evidence that antioxidants did interfere with the therapeutic effect of chemotherapy and, on the contrary, suggest that the hypothesis that it would increase the efficacy. He is properly cautious, but anyone reading his paper knows that is clear the probability that these antioxidants prevent the therapeutic axtivity of chemotherapy is very low, and the probability that they do the opposite, i.e. enhance the action of these toxic drugs, is relatively high. Prasad et al (6) concluded, "Antioxidants such as retinoids, vitamin E, vitamin C and carotenoids inhibit the growth of cancer cells. These antioxidants individually and in combination, enhance the effects of x-irradiation, chemotherapeutic agents, and certain biological response modifiers such as hyperthermia, sodium butyrate, and interferon, on cancer cells. Antioxidants individually protect normal cells against some of the toxicities produced by these therapeutic agents. Therefore, the fear of oncologists and radiation therapiests that these antioxidants may protect cancer cells against free radicals that are generated by these agents is unfounded. It should be pointed out that other antioxidants such as sulfhydryl compounds will protect cancer cells at least against radiation damage. This is not true for any of the proposed antioxidants vitamins and carotenoids." Even earlier Charles B. Simone et al (7) on the basis of a large number of clinical studies (he also examined 71 scientific papers) came to the same conclusion. He reported "In a recent study of 50 patients with early-stage breast cancer I evaluated the treatment side effects of radiation alone, or radiation combined with chemotherapy, while the patients took therapeutic doses of nutrients. Patients also followed the Simone Ten Point Plan. Patients were asked to evaluate their own response to the treatment in terms of its impact on the quality of life. The results of the study were impressive. "MOre than 90% of both groups noted improvement in their physical symptoms, cognitive ability, performance, sexual function, general well-being and life satisfaction. Not one subject in either group reported a worsening of symptoms." He concluded, "...cancer patients should modify their lifestyles using the Ten Point Plan, which included modifying nutritional factors and taking certain vitamins and minerals especially if they are receiving chemotherapy, and/or radiation." Labriola et al (8) concluded that vitamin C may prevent the therapeutic effect of chemotherapy if given concurently and recommended that antioxidants be withheld until after the chemotherapy is completed. It is not clear whether they meant that the antioxidants should be withheld throughout the entire series of chemotherapy sessions or that is should be withheld only for the day that chemotherapy is given. If the latter is his suggestion, there is no harm done to the patients. Most of them cannot take anything, including vitamins, during these sessions. He based his conclusions on one case which suggested this had happened and upon a hypothetical examination of the role of free radicals and antioxidants on the action of chemotherapy on cancer cells. His report elicited two rebuttals, Reilly (9) and Gignac (10). I will not repeat the arguments, but it was evident that Dr. Labriola was not convinced by the points put forward by Reilly and Gignac. I think the factoid repeated by Dr. Labriola would have a much better chance of becoming a fact if he had considered the following points: 1) What is the therapeutic value of chemotherapy without any antioxidants? Even within the field of standard oncology there is a debate whether chemotherapy has any merit except for a small number of cancers (Moss 11). Before one can claim that a treatment has been inhibited, surely there must be pretty good evidence that treatment has any merit to begin with. It is possible (we do not know the probability for this) that chemotherapy interferes with the therapeutic value of the antioxidants. Almost all the studies testing large doses of vitamin C yielded positive results while there was no such unanimity with respect to chemotherapy. Letter by Dr. Abram Hoffer, founder of Orthomolecular Medicine Remember we are NOT Doctors and have NO medical training. This site is like an Encylopedia - there are many pages, many links on many topics. Support our work with any size DONATION - see left side of any page - for how to donate. You can help raise awareness of CAM.