Study Linking Multivitamins, Prostate Cancer Questioned By Trade Groups
This article was originally published in The Tan Sheet
Executive Summary
Supplement trade groups cite limitations inherent to observational studies as one reason they question results from a study associating excessive multivitamin use with prostate cancer
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Supplement trade groups cite limitations inherent to observational studies as one reason they question results from a study associating excessive multivitamin use with prostate cancer. The prospective observational study published in the Journal of the National Cancer Institute May 16 evaluated the relationship between multivitamin use and prostate cancer in 295,344 men enrolled in the National Institutes of Health-American Association of Retired Persons Diet and Health Study. Results show participants who reported excessive multivitamin use - defined as more than seven times per week - had double the risk of fatal prostate cancer compared to those who did not take multivitamins, Karla A. Lawson, Ph.D., National Cancer Institute, et al., state. The researchers cited limitations that may have influenced the results, including a lack of information on the duration of multivitamin use and potential detection bias for participants more likely to be screened for prostate cancer, such as those with a family history of the disease. Council for Responsible Nutrition Vice President of Scientific and Regulatory Affairs Andrew Shao, Ph.D., said Lawson et al. also "acknowledge that people who use supplements tend to exhibit more healthy behavior like seeing their physician on a more regular basis and getting screened, which could lead to a bias." While the researchers also drew a link between increased prostate cancer risk and excessive multivitamin use with concomitant use of single vitamins and minerals, "they found no relation between single vitamins and minerals alone," Shao said. "So they're seeing some associations here, but clearly they're not cause or they really can't establish that from the study, and the authors acknowledge that," he added. The Natural Products Association has similar comments. "The very nature of statistics is that any researcher with many outcome measures, as was the case in this study, will stumble upon a figure that suggests some kind of an effect where there is none," NPA Vice President of Scientific and Regulatory Affairs Daniel Fabricant, Ph.D., said in a release. - Jessica Lake ([email protected]) |