Friday, September 07, 2018 by Isabelle Z.
We all know that vitamins are healthy. Whether you take a multivitamin or not, no one can deny that our bodies need nutrients for functioning and good health. What’s more debatable, however, is whether or not multivitamins are effective. Many people swear by them, while others think they’re just a waste of money. Adding to the confusion are studies that appear to reach conflicting conclusions. Now, however, one expert is cautioning that some studies aren’t using the proper methodology.
As the senior scientist at the Antioxidants Research Lab at Tufts University’s Jean Mayer USDA Human Nutrition Research Center on Aging, Dr. Jeffrey Blumberg is very familiar with vitamins. He says that a recent, highly publicized meta-analysis that found multivitamins don’t help prevent heart disease was inherently flawed.
The study in question, which was published in the Journal of the American College of Cardiology and entitled, “Supplemental Vitamins and Minerals for CVD Prevention and Treatment,” declared that multivitamins containing the letter vitamins as well as several minerals did not reduce people’s risk of cardiovascular disease or their overall mortality.
One of his criticisms is that it provided little in the way of new evidence over the study that preceded it. It included 179 studies, which is a significant number, but only 15 of them had been published since the last meta-analysis was carried out. Therefore, the new studies would have needed some pretty big results to make a dent in the results of the earlier meta-analysis.
While he doesn’t want to be too critical of the meta-analysis because it did meet the standard practices for a study of its type, he did feel that they may have been asking some of the wrong questions in the first place. He said that there are other questions that should have been explored to look at the effects of the multivitamins rather than sticking to cardiovascular disease risk and overall mortality, For example, improvements in physiological functions like lower blood pressure, enhanced immunity, or better cognitive function could have been explored. In any case, he feels the purpose of vitamins isn’t to prevent mortality in the first place.
He pointed out that in a long-term study, the average heart disease onset in a control group might be five years, for example, and ten in the group that took multivitamins. In a study that’s 15 years long, therefore, you’ll see the same number of people ending up with heart disease so there wouldn’t be a visible overall effect. At the same time, however, there is indeed a big difference in the quality of life that those who enjoyed five more healthy years before developing the disease experienced, and that wouldn’t be clear at all by just reporting on the overall risk.
Moreover, he feels that controlling for the type of multivitamins used is a difficult task and made the results more like comparing apples to oranges. After all, multivitamins can vary significantly among the brands in terms of their composition. Some include or exclude entire groups of vitamins or minerals, and the amounts they contain can vary wildly. Although the researchers say they did control for this, he feels some of the studies included didn’t even offer enough details for that to be possible.
Any time a study is released, it’s always important to take a close look at the methodology that was used as well as any industry connections the researchers involved may have. Some people struggle to get adequate nutrition from the foods they eat for a variety of reasons, and it would be a shame if they overlooked multivitamins as a valuable source of nutrients because of a misleading study.
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