MULTIVITAMINS, VITAMIN C SUPPLEMENTS, AND BLADDER CANCER RISK
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.
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(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.
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