Unfortunately this is not always what happens in the mainstream world of health and wellness reporting. All too often there will be a headline or a statement made by some agency stating for example, ”Women who take a multi vitamin are at an increased risk for all types of death.” This is exactly what happened recently in a journal article, “Dietary Supplements and Mortality Rate in Older Women,” published in the Archives of Internal Medicine, 2011, Volume 171(18):1625-1633.” It would all seem rather legitimate being from a respected Medical Journal, but if you really look at the study design you will see blatant flaws which render statements like this to be completely illegitimate and out of touch with evidence based science. Unfortunately when there is an agenda at hand the powers that be can easily use their status to promote whatever statements they want the general public to believe. I have attached a review of this study and the link here, and I urge you to read what it says. It may shed some light on the things that you often hear touted on the TV, radio, or in magazines.
Should you choose not to read these three pages let me provide for you a quick synopsis of the main points:
- This study followed 38,772 women over 18 years with an initial intake and two follow up questioners that were mailed in by the participants. The questionnaires inquired about lifestyle practices, food intake, dietary supplement use, weight, smoking status, hormone replacement therapy, and the presence of diabetes or heart disease.
- Although study participants were asked about their intake of dietary supplements, the study did not report how much of any specific nutrient was consumed. Nor was information elicited from the women regarding the chemical form of the supplement (e.g., picolinate versus sulfate) or the quality of the supplements that were taken.
- No attempt was made to verify the accuracy of the answers provided in the questionnaires, nor were any of the participating women asked why they were taking supplements, and no attempt was made to determine the impact of taking—or not taking—supplements on any specific individual.
- In weighing the study’s findings, however, it must be emphasized that the Iowa Women’s Health Study is a retrospective study of already collected data. It is not a prospective, controlled intervention study, i.e., it is not a “clinical trial,” in which participants would be given a specific dietary supplement or a placebo and then followed closely over time to observe not only the specific outcomes but also the factors possibly contributing to those outcomes.
- “…simple association does not reflect causation. “