FRIEDRICHSDORF, Germany, August 25, 2011 /PRNewswire/ --
Might antioxidant vitamins such as vitamins C and E or provitamin A (beta-carotene) be able to prevent cancer and other chronic diseases and hence prolong life? A recent study indicates that vitamins may play an important role in the prevention of such diseases. In the course of the study scientists examined 23,943 men and women for the German Cancer Research Centre in Heidelberg as part of a pan-European prospective investigation (1). The results of the observational study showed: participants who were already regularly taking antioxidant vitamins at the start of the study were at a significantly lower risk of dying of cancer and had lower overall mortality than participants who did not take any multivitamin products. The pros and cons of taking supplementary vitamins and minerals as protection against lifestyle diseases like cancer and cardiovascular disease or death from any cause has long been the subject of numerous research projects and is often controversially debated. Since the prevention and development of this type of chronic disease depends on many factors, as a rule it is difficult to prove what exactly has had a preventive effect. In the end, how long we live probably depends on a combination of diverse lifestyle elements and genetic factors. The study revealed that users of dietary supplements appear to be generally more health conscious and live a more active lifestyle.
Researchers list several reasons for the contradictions found in studies in this field. Apart from the fundamental problem that preventive effects of micronutrients cannot be shown or even measured as simply as the therapeutic effects of drugs in clinical studies, the vitamin status of participants at the beginning of a study appears to play a crucial role: participants who start out with an adequate supply of vitamins do not demonstrate any increased preventive effect from additional vitamin intake. Dietary supplements only appear to have a health benefit for people with vitamin deficits.
Genetic factors can also influence vitamin requirements and their effectiveness. Recent studies show that people with certain gene variants (polymorphisms) for the enzymes responsible for vitamin metabolization can only utilize these micronutrients to a limited degree (2,3). In consequence people with these not uncommon gene variants may have a higher vitamin requirement and therefore benefit from an additional intake of vitamins.
Interpretation of study outcomes that at first glance appear to indicate a possible connection between increased vitamin intake and harmful effects must take into account other potential triggers and the time of disease occurrence, say experts. In the present study, for example, participants who started taking vitamins during the course of the study were shown to have an increased mortality risk. According to the researchers this was not due to the effect of the vitamins, but to the fact that these people only started taking vitamin products during the study, once they had already developed a disease and it was too late for any possible preventive effects.
1. Li K. et al. Vitamin/mineral supplementation and cancer, cardiovascular, and all-cause mortality in a German prospective cohort (EPIC-Heidelberg). European Journal of Nutrition, July 2011.
2. Blum S. et al. Vitamin E reduces cardiovascular disease in individuals with diabetes mellitus and the haptoglobin 2-2 genotype. Pharmacogenomics. 2010; 11(5): 675-684.
3. Eric B. Rimm and Meir J. Stampfer. Folate and cardiovascular disease: one size does not fi t all. http://www.thelancet.com, published online August 1, 2011.
CommuniPoweR Wolfgang Zöll
SOURCE CommuniPoweR Wolfgang Zoll