High Doses of Multiple Antioxidant Vitamins: Essential Ingredients in Improving the Efficacy of Standard Cancer Therapy

Abstract

Numerous articles and several reviews have been published on the role of antioxidants, and diet and lifestyle modifications in cancer prevention. However, the potential role of these factors in the management of human cancer have been largely ignored. Extensive in vitro studies and limited in vivo studies have revealed that individual antioxidants such as vitamin A (retinoids), vitamin E (primarily alpha-tocopheryl succinate), vitamin C (primarily sodium ascorbate) and carotenoids (primarily polar carotenoids) induce cell differentiation and growth inhibition to various degrees in rodent and human cancer cells by complex mechanisms. The proposed mechanisms for these effects include inhibition of protein kinase C activity, prostaglandin E1-stimulated adenylate cyclase activity, expression of c-myc, H-ras, and a transcription factor (E2F), and induction of transforming growth factor-beta and p21 genes. Furthermore, antioxidant vitamins individually or in combination enhance the growth-inhibitory effects of x-irradiation, chemotherapeutic agents, hyperthermia, and biological response modifiers on tumor cells, primarily in vitro. These vitamins, individually, also reduce the toxicity of several standard tumor therapeutic agents on normal cells. Low fat and high fiber diets can further enhance the efficacy of standard cancer therapeutic agents; the proposed mechanisms for these effects include the production of increased levels of butyric acid and binding of potential mutagens in the gastrointestinal tract by high fiber and reduced levels of growth promoting agents such as prostaglandins, certain fatty acids and estrogen by low fat. We propose, therefore, a working hypothesis that multiple antioxidant vitamin supplements together with diet and lifestyle modifications may improve the efficacy of standard and experimental cancer therapies.

Interaction between antioxidant vitamin supplementation and cigarette smoking during radiation therapy in relation to long‐term effects on recurrence and mortality: A randomized trial among head and neck cancer patients

“…The intervention began on the first day of radiation treatment since a beneficial effect of antioxidant supplementation during radiotherapy was anticipated. 13 The supplementation with beta carotene was discontinued after 156 patients had been enrolled into the trial, because of ethical concerns following the release of the beta-carotene and retinol efficacy trial results in January 1996. 9 The trial was continued with alpha-tocopherol alone.…”

Nutrition in oncology: the case of micronutrients (Review)

“…Thus, the adjuvant supply during chemo and radiation therapy is recommended (60,64) on the one hand, and there is the opposite opinion warning against such a measure (65,66) on the other. These divergent views can be explained, among other things, by the fact that the influence of an antioxidant supplementation on the effect of chemo or radiation therapy seems to depend on a number of factors (147): i) degree to which radicals are formed by the chemotherapeutic agent and in how far the chemotherapeutic effect depends on the potential formation of free radicals; ii) type of reactive oxygen compounds formed by the chemotherapeutic agent;…”

“…Meanwhile a large number of survey studies (60)(61)(62)(63)(64)(65)(66)(153)(154)(155)(156)(157)(158)(159) have been published, some of a systematic nature (56,57), summarizing and evaluating the findings. In this context, two contradictory positions have developed expressed by two different views (147) maintaining that the administration of antioxidant supplements (in higher doses) as an adjuvant to chemo and/or radiation therapy: i) is not associated with any negative effects on the tumordestroying therapy; and ii) is associated with a weakening of the tumor-destroying therapy.…”

“…Against this background it is evident that a supportive nutrition therapy should be an integral part of cancer care (44)(45)(46). In addition to a sufficient supply of energy substrates, vitamins and minerals as well as long-chain ˆ-3 fatty acids are becoming more and more interesting (31, [47][48][49][50][51][52][53][54][55][56], although the therapeutic benefit of such supplements is the subject of a controversial discussion, especially in respect ONCOLOGY REPORTS 24: 815-828, 2010 of supplements with high concentrations of antioxidants like the vitamins C and E and the trace element selenium (57)(58)(59)(60)(61)(62)(63)(64)(65)(66).…”

Transplastomic plants for innovations in agriculture. A review

“…Animals and humans cannot synthesize vitamin E; they must fulfill their requirement of vitamin E by uptaking plant and/or algal tocopherols in their diet. By preventing lipid peroxidation, vitamin E reduces the risk of a number of serious human disorders, including cardiovascular disease (Pryor 2000), cancer (Prasad et al 1999), Alzheimer's disease (Mangialasche et al 2010), and other chronic diseases (Traber et al 2008), and also enhances the function of the immune system (Adachi et al 1997). Due to the high nutritional value and benefits of vitamin E in human health, increasing the tocochromanol content of major crops has long been in the focus of breeding programs and transgenic engineering approaches (Hirschberg 1999;DellaPenna 2005;Karunanandaa et al 2005).…”