Cancer Adjuvant Therapy
The inhibitory role of vitamin E in the growth of a number of human tumor cells, as well as its defensive functions in overcoming treatment-induced toxicity have been examined. The impact of vitamin E (perhaps acting through its antioxidant strengths) is significant, as evidenced by the following studies:
After examining 29,000 male smokers in Finland, researchers found that high blood levels of alpha-tocopherol reduced the incidence of lung cancer by approximately 19%. The relationship appears stronger among younger persons and among those with less cumulative smoke exposure. These findings suggest that high levels of alpha-tocopherol, if present during the early critical stages of tumorigenesis, may inhibit lung cancer development (Woodson et al. 1999).
A combination of vitamin E and pentoxifylline (PTX), a drug that inhibits abnormal platelet aggregation, allowing more blood to reach irradiated areas, resulted in a 50% regression of superficial radiation-induced fibrosis (the proliferation of fibrous connective tissue) in half of the patients studied (Gottlober et al. 1996; Delanian 1998). A suggested dosage is 800 mg a day of PTX and 1000 IU per day of vitamin E.
An antimelanoma effect obtained from vitamin E succinate in vivo has been reported (Malafa et al. 2002).
Gamma-tocopherol inhibits COX-2 activity, demonstrating anti-inflammatory properties (Jiang et al. 2001; Life Extension Magazine 2002).
The use of vitamin E, in combination with vitamins A and C, led to a four-fold reduction in p53 mutations (Brotzman et al. 1999). This is an extremely important finding because p53 mutations indicate a more malignant, aggressive form of cancer.
Men with a high intake of vitamin E are 65% less likely to develop colorectal adenomas (precursors to colon cancer) compared to men with low vitamin E intake (Tseng et al. 1996).
Lower morbidity and mortality from prostate cancer in men taking 50 mg of synthetic alpha-tocopherol daily. Subsequent testing determined gamma-tocopherol to be superior, however, to alpha-tocopherol in terms of tumor cell inhibition (Moyad et al. 1999). Men in the highest fifth of the distribution for gamma-tocopherol had a five-fold reduction in the risk of developing prostate cancer compared to those in the lowest fifth. In addition, statistically significant protection from high levels of selenium and alpha-tocopherol occurred only when gamma-tocopherol concentrations were also high (Helzlsourer et al. 2000). Vitamin E's mode of efficacy in regard to prostate protection: Vitamin E interferes with two proteins (the receptor for testosterone and prostate-specific antigen [PSA]). The fewer androgen receptors there are on a prostate cancer cell, the less capable the remaining receptors are of turning on genes that stimulate prostate cancer growth and progression. PSA serves as a good marker molecule for androgen receptor activity (Mercola 2002b).