Positive Health Online

Abstract

PATTERSON and colleagues, Fred Hutchinson Cancer Research Center, Seattle, WA USA reviews (89 references) published epidemiological research regarding the association of vitamin and mineral supplementation and cancer risk.

Background

Methodology

Results

Although there is a vast literature on nutrition and cancer, few studies published to date (7 clinical trials, 16 cohort and 36 case-control studies) have addressed supplemental nutrients directly . These studies demonstrate the effects of nutrients which are distinguishable from the effects of biologically active compounds in foods. Randomised clinical trials have not demonstrated significant protective effects of beta-carotene, but have found protective effects of vitamin E against prostate cancer, vitamin A and zinc and beta-carotene, vitamin E and selenium against stomach cancer and selenium against total, lung and prostate cancers . Cohort studies provide scant evidence that vitamin supplements are associated with cancer. Case-control studies have demonstrated an inverse association between vitamin C and bladder cancer, several supplemental vitamins and oral/pharyngeal cancer and vitamin E and several cancers. Inverse associations between vitamin E and colon cancer have been found by a randomised clinical trial, a cohort study and a case-control study.

Conclusion

: There is, overall, modest evidence regarding the protective effects of nutrients from supplements against a number of cancers. Future studies of vitamin supplement use and cancer are justified however, methodological problems which impede the ability to assess supplement use, and statistical modelling of the relation between cancer risk and supplement use require ironing out.

References

Patterson RE et al. Vitamin supplements and cancer risk: the epidemiological evidence. Cancer Causes Control. 8(5): 786-802. Sep 1997.