The study – published in the Canadian Journal of Physiology and Pharmacology (CJPP) – found that rats given regular multivitamin and mineral supplements showed a significantly lower risk of developing colon cancer when they were exposed to carcinogens.
“Multivitamin and mineral supplements synergistically contribute to the cancer chemopreventive potential, and hence, regular supplements of multivitamins and minerals could reduce the risk of colon cancer,” explained the authors, led by Dr Ignacimuthu Savarimuthu of Loyola College, India.
Commenting on the study, Dr. Grant Pierce, Editor of CJPP said: "It has been unclear whether multivitamin supplementation to cancer patients is helpful, has no effect, or is even detrimental during therapy,"
Dietary nutrients “are well documented to be chemopreventive in the epidemiology of colon cancer,” said the authors, noting that there has been ‘considerable’ interest in establishing the role of particular nutrients, either individually or in combination, to prevent colon cancer.
“Research on multivitamin and mineral supplementation from diet and cancer are often speculative”, said the research team. However there have been several epidemiological studies in recent years that have linked dietary nutrients to colon cancer risk – including one reporting a ‘strong association’ with vitamins A, C, and E , and other studies linking vitamin B and vitamin D status to risk of the cancer.
“Although the specific dietary factors responsible for this protective effect have not been clearly identified, [it is clear that] fruits and vegetables contain vitamins and minerals that may influence cancer,” said the researchers
“The objective of this study was to show that including vitamin and mineral supplements in a regular diet could reduce cancer risk and protect against carcinogenesis,” they explained.
Ignacimuthu and colleagues split rats into 6 groups, which were then exposed to different combinations of supplements and carcinogens (1,2-dimethylhydrazine) – DMH-induced rat colon carcinogenesis is one of the most widely studied experimental models in cancer chemoprevention studies. The authors added that all rats were fed a high-fat diet (20% fat) over the 32 week study period.
They revealed that rats fed a high-fat plus low-fibre diet and exposed to carcinogens developed pre-cancerous lesions; whereas, rats undergoing similar treatment, but provided with daily multivitamin and mineral supplements, showed an 84% reduction in the formation such of pre-cancerous lesions, and did not develop tumours.
“Multivitamin and mineral supplementation during the initiation, post-initiation, and the entire study period significantly decreased the levels of lipid peroxidation products in circulation and colonic tissues, significantly elevated the activities of the antioxidant enzymes and reduced glutathione to near normalcy in DMH-induced rats,” wrote the authors.
Source: Canadian Journal of Physiology and Pharmacology
Volume 90, Issue 1, Pages 45-54, doi: 10.1139/y11-100
“Multivitamin and mineral supplementation in 1,2-dimethylhydrazine induced experimental colon carcinogenesis and evaluation of free radical status, antioxidant potential, and incidence of ACF”
Authors: A.B. Arul, I. Savarimuthu, M.A. Alsaif, K.S. Al Numair