Written by Marcia J. Egles, MD. In smokers, researchers concluded that vitamin E, carotenoids, and niacin reduced the risk of bladder cancer by 42%, 38%, and 34% respectively.
Bladder cancer is a cancer which arises in the urinary bladder, the pouch-shaped organ which stores urine. Risk factors include cigarette smoking and occupational exposures to toxins such as aromatic amines (1). Since the bladder lining is directly bathed in urine containing many substances which the body discards, it is not surprising that toxic exposures are associated with higher risks of bladder cancer.
The bladder lining is likewise exposed to minerals, vitamins, and metabolites that the body sends to the urine. Several studies have reported that dietary factors such as fruits and vegetables may be protective against bladder cancer ( 2,3,4,5). Other studies have found no effect (1). The 2007 report by the American Institute of Cancer Research states that the evidence was too limited to conclude that any food or nutrient directly influences the risk of bladder cancer (6). The aim of this new study from a region of high bladder cancer incidence, was to investigate the association between dietary minerals and vitamins and the risk of bladder cancer (7).
The study was a case-control study of New Hampshire residents. Dietary information was collected by interview of 322 persons with bladder cancer and 239 controls (similar persons who did not have bladder cancer). The average age of those with bladder cancer was 62 and 74 per cent were male.
In a case-control study, patients who have a disease (in this study bladder cancer) are compared with peers who do not have the disease. Past information, such as diet histories, is gathered and then compared between the two groups using “odds ratios”. The odds ratios point out factors that are associated with a disease. The closer the odds ratio is to the number one, the smaller the difference is in the factor’s association between the cancer group and the control group. That is, if the odds ratio is one, as was found for dietary iron intake in this study, there’s no difference found between the two groups and iron intake was not found to be associated with bladder cancer.
The study was able to suggest some protective effects of several vitamins in subsets of patients who were at highest risk for bladder cancer. The odds ratios for heavy smokers with the highest intakes of vitamin E, carotenoids, and niacin were 0.58, 0.62 and.66 respectively. Similarly, in those older than 63 years, higher intakes of carotenoids, vitamin D, thiamine, niacin, and vitamin E were associated with reduced odds ratios against bladder cancer. Higher phosphorus intakes also emerged with reductions in bladder cancer odds ratios, but the trends were not consistently statistically significant. Sodium, potassium, magnesium, calcium and iron intakes were also evaluated, but no associations were found.
The researchers concluded that further study of vitamin E, carotenoids, vitamin D, thiamin and niacin and their role in bladder cancer prevention, may be warranted, particularly in smokers and older individuals.
Definitions:
Cartenoids – Yellow to red materials from plants and animals consuming them similar to vitamin A.
Niacin – A B Complex vitamin sometimes called B3.
Source: Brinkman, Maree T., et al. “Minerals and vitamins and the risk of bladder cancer: results from the New Hampshire Study.” Cancer Causes & Control 21.4 (2010): 609-619.
© The Author(s) 2009. This article is published with open access at Springerlink.com
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Posted January 14, 2010.
References:
- Pelucchi C et al (2006) Mechanisms of disease: the epidemiology of bladder cancer. Nat Clin Pract Urol 3:327-340.
- Riboli E, Norat T (2003) Epidemiologic evidence of the protective effect of fruit and vegetables on cancer risk. Am J Clin Nutr 78:559S–569S.
- Castelao JE, Yuan JM, Gago-Dominguez M et al (2004) Carotenoids/vitamin C and smoking-related bladder cancer. Int J Cancer 110:417–423.
- Zeegers MP, Goldbohm RA, van den Brandt PA (2001) Consumption of vegetables and fruits and urothelial cancer incidence: a prospective study. Cancer Epidemiol Biomarkers Prev10:1121–1128.
- Steinmaus CM, Nunez S, Smith AH (2000) Diet and bladder cancer: a meta-analysis of six dietary variables. Am J Epidemiol 151:693–702.
- World Cancer Research Fund/ American Institute for Cancer (2007) Food, nutrition, physical activity, and the prevention of cancer: a global perspective. AIRC, Washington DC.
- Maree T. Brinkman, Margaret R. Karagas et al. Minerals and vitamins and the risk of bladder cancer: results from the New Hampshire Study Cancer Causes Control, Dec. 31,2009.
