According to the Skin Cancer Foundation, basal cell skin cancer is not only the most common skin cancer, it is the most common of all cancers. More than one-third of all new cancers are skin cancers; and the majority of these cases are basal cell carcinomas. Controversial research is now trying to understand what dietary factors can prevent, or in fact promote, this skin cancer.
What is Basal Cell Skin Cancer?
A relatively slow-growing cancer, basal cell skin cancer arises from the basal cells within the bottommost layer of the epidermis, which is the top layer of your skin. The primary cause of this cancer is sun exposure. Thought to be a condition that afflicts older persons, including former President Bill Clinton, with many years of sun exposure, basal cell skin carcinoma is occurring in greater numbers in people in their 20s and 30s.
The Role of Vitamin A
Harvard researchers reported in Cancer Epidemiology Biomarkers Prevention in 2004 that supplementation with beta-carotene, a carotenoid converted to vitamin A within the body, did not affect risk of non-melanoma skin cancers, including basal cell carcinoma, in men with a low baseline plasma beta-carotene levels.
That no effect was found in the Harvard study does not surprise German researchers, who believe that beta-carotene may actually promote the progression nonmelanoma skin cancers. "Recent studies on skin cells in culture have revealed that beta-carotene acts not only as an antioxidant but also has unexpected pro-oxidant properties. At present, there is an ongoing debate on the protective or potentially harmful role of beta-carotene in human skin," said Hans K. Biesalski, M.D., in the Archives of Biochemistry and Biophysics in 2001.
Vitamins C and E
According to Nutrition Views, vitamins C and E seem to exert protective effects given their physiological synergism. In the study, 40 volunteers were either given vitamin C alone as ascorbic acid; vitamin E alone as alpha tocopherol; both vitamins together; or a placebo -- a control condition in which a pill containing neither vitamin was administered.
Researchers found that the serum level of vitamins in those subjects who took the vitamins was higher compared to the control condition. Additionally, when exposed to ultraviolet radiation, the subjects who took both vitamins had a less severe sunburn
reaction.
Green Tea
Researchers reported in the "Journal of Investigative Dermatology" in 2009 that green tea polyphenols, or GTPs, may inhibit development of skin tumor in mice exposed to ultraviolet radiation. The researchers identified a specific immune marker, IL-12, through which GTPs are thought to induce this effect.
References
- "Cancer Epidemiology Biomarkers Prevention"; No Effect of β-Carotene Supplemenation On NonMelanoma Skin Cancers Among Men With Low Baseline Plasma β-Carotene Levels; Debra A Schaumberger et al.; 2004
- "Archives of Biochemistry and Biophysics"; UV Light, Beta-Carotene, and Human Skin: Beneficial and Potentially Harmful Effects; Hans K Biesalski et al; 2001
- "Journal of Investigative Dermatology"; Inhibition of UVB-Induced Skin Tumor Development by Drinking Green Tea Polyphenols Is Mediated Through DNA Repair and Subsequent Inhibition of Inflammation; Syed M Meeren et al.; 2009
