Multivitamins, Vitamin C Supplements, and Bladder Cancer Risk
Previous studies have reported that high levels of dietary vitamin C correlate with decreased risk of bladder cancer,(1) vitamin E with a trend toward protection, and beta-carotene with no link at all to bladder cancer risk.(2) While not every trial finds a relationship between bladder cancer and nutrition,(3) bladder cancer recurrences have been reported to markedly decrease in a double-blinded trial when patients are given multivitamin/mineral pills plus 40,000 I.U. vitamin A, 100 mg vitamin B6, 2 g vitamin C, 400 I.U. vitamin E, and 90 mg zinc for ten months.(4) Long-term follow-up of these patients revealed a 46% decrease in recurrences at five years.(5)
Recently in a case-control trial, researchers from Fred Hutchinson Cancer Research Center in Seattle reported a dose-dependent reduction in risk with intake of retinol (top quintile of intake had a 48% decreased risk compared with the bottom) and vitamin C (which halved risk at the top quintile level).(6) Most remarkable was the 61% decreased risk of bladder cancer tied to use of multivitamins taken for a decade and a 60% decreased risk for those taking more than 500 mg of vitamin C for the same period of time. This may be the first bladder cancer trial to report a dramatic reduction in risk associated with multivitamin and vitamin C use. Either vitamin C or multivitamin supplementation could simply be a marker for other health-preserving behavior, but mechanisms suggesting anticancer activity for folate, vitamin B12, calcium, vitamin D, and antioxidants suggests that the protective effect may well prove to be real.
(1) Nomura AMY, Kolonel LN, Hankin JH, Hoshizawa CN. Dietary factors in cancer of the lower urinary tract. Int J Cancer 1991; 48:199-205.
(2) Riboli E, Gonzalez CA, Lopez-Abente G, et al. Diet and bladder cancer in Spain: a multi-centre case-control study. Int J Cancer 1991; 49:214-9.
(3) Vena JE, Graham S, Freudenheim J, et al. Diet in the epidemiology of bladder cancer in Western New York. Nutr Cancer 1992; 18:255-64.
(4) Lamm DL, Riggs DR, Shriver JS, et al. Megadose vitamins in bladder cancer: a double-blind clinical trial. J Urol 1994; 151:21-6.
(5) Lamm DL Riggs DR, Carpenter C, DeHave JI. Long term results of high-dose vitamin administration in patients with superficial bladder cancer. J Am Coll Nutr 1995; 14:535 [abstr #45].
(6) Bruemmer B, White E, Vaughan TL, Cheney CL. Nutrient intake in relation to bladder cancer among middle-aged men and women. Am J Epidemiol 1996; 144:485-95.
Article copyright Natural Product Research Consultants, Inc.