For those of us who learned that taking mega dose vitamin C for the common cold, as advocated by the late Nobel Laureate Linus Pauling, was truly something to sneeze at, I always approach studies lauding the effects of nutrient-based therapies with a mega dose of skepticism.
Regarding vitamin C in particular, I am not alone. The following is from the conclusion from Duerbeck at al (1):
|Even the most cursory Internet search will find multiple testimonials stating that vitamin C is beneficial for the treatment of just about anything that ails you, including the common cold, bronchitis, acne, human immunodeficiency virus, stomach ulcers, cataracts, tuberculosis, dysentery, urinary tract infections, prostatitis, depression, dementia, Alzheimer disease, attention-deficit/hyperactivity disorder, preterm labor, preeclampsia, cardiovascular disease, stroke, cancer, and facial wrinkles.|
|Perhaps the disappointing results of vitamin C supplementation studies and lack of hope for beneficial effects on decreasing preeclampsia, preterm labor, cardiovascular disease, blindness, respiratory tract infection, dementia, and cancer are that investigators are looking at oxidative stress from the wrong perspective. It may be that, rather than being a cause of disease, free radicals might be a consequence of it. If so, perhaps vitamin C has no effect on morbidity and mortality because the byproduct of the disease process is being treated rather than the disease itself…|
|It seems that many vitamins have emerged and been purported as potentially of benefit in prevention and treatment of disease. With most, rigorous studies have failed to duplicate the results of small, initial reports. In the published media, and even more so on social media, a retraction or negative study is never as widely publicized as the original positive results. However, now that the greatest proponent of vitamin C, Dr Pauling, has passed, it is perhaps not surprising that orange juice sales for 2013 to 2014 dropped to the lowest levels in 16 years, down 40% from 1998.54 In medicine, just like late-night TV commercials, if it sounds too good to be true, well, it just may be.
Trying to be open-minded, I can understand why vitamin C has potential in the management of non-melanoma skin cancer. According to Payette et al (2):
Vitamin C, or ascorbic acid, can be found in green leafy vegetables, citrus fruits, berries, cantaloupes, tomatoes, potatoes and herbs. Vitamin C has been shown to function as a free radical scavenger and may protect cells against UV-induced DNA damage and lipid peroxidation, as well as augment the immune response, restore the activity of other antioxidants, and stabilize intracellular matrices. In vitro studies have demonstrated a protective effect of vitamin C with regard to NMSCs… In porcine models, topical application of vitamin C protected against UVB-induced lipid peroxidation, decreased erythema, and limited UVB- and psoralen and long-wave UVR-induced photodamage. One murine study demonstrated that administration of vitamin C reduced DNA, RNA, and protein synthesis in BCCs and SCCs by 50% after topical application of the carcinogen 3-methylcholanthrene. Diets supplemented with vitamin C resulted in significantly fewer SCCs in hairless mice after exposure to UV light during a 15-week period compared with standard diets or diets supplemented with vitamin E.
Holló et al treated 7 BCCs (1 nodular and 6 superficial) with an application of topical saturated ascorbic acid solution applied daily for 12 hours under occlusion. For 6 lesions the treatment was continued for 22 weeks and only for 13 weeks in 1 case because of an excellent response by week 13. Post-treatment biopsies demonstrated tumor-free tissue in the nodular BCC and 4 superficial BCCs, while 2 superficial BCCs had residual tumor; these were subsequently excised. Regardless of whether the potential efficacy is due to anti-oxidant or inflammatory effects, the authors suggest that further studies are warranted.
I agree. You know how patients crave “natural” therapies. Although I remain a skeptic, it would be marvelous to offer ascorbic acid as a therapeutic option for treating BCCs. We’ll C.
- Duerbeck NB, et al. Vitamin C: Promises not kept. Obstet Gynecol Surv 2016; 71: 187-93.
- Payette MJ. Nutrition and non-melanoma skin cancers. Clin Dermatol 2010; 28: 650-662.
- Holló P, et al. Topically applied ascorbic acid solution for the treatment of basal cell carcinoma. J Am Acad Dermatol 2016; 75: 212-3.