The number of “surprising”reports on the uselessness of vitamin supplements seem to have been increasing as of late.
A recent huge study (Neuhouser et al., 2009) is just the latest to find that earlier studies claiming health benefits for supplements may have been jumping the gun. It’s actually astounding that in a study with nearly 162,000 participants, absolutely no statistical differences were found in cases of cancer, cardiovascular disease, or death between vitamin users and non-users. Such enormous studies are actually prone to spurious statistical effects that have no biological relevance. The power of a study like this is extreme enough that the results are not just negative, but emphatically negative.
As meta-analyses (studies combining all previous relevant studies into one analysis) and ever larger additional studies are showing, we really aren’t as smart at reductionist nutrition as we thought we were. So far, the only place you can find food reduced to a set package of nutrients is still a fifty-year-old science fiction novel.
In fact, humans have evolved as omnivores over the millenia to utilize a vast array of food items. Nutrition for a panda might be relatively easy to figure out, but for us, it is not. Although we have identified a certain number of compounds that appear to be essential for avoiding certain acute diseases – if you don’t want scurvy, make sure you get adequate vitamin C – the proposition that simple individual nutrients could prevent long-term conditions such as heart disease or cancer is likely a pipe dream.
Furthermore, it is unlikely that most nutrients work in a vacuum. We do know that without vitamin D, calcium is not absorbed well, but there are likely countless other complex interactions that affect our physiology over both the short and long term, involving both nutrients we know about and those that we don’t. When you add in the difficulty of knowing the appropriate amounts of probably thousands of complexly interacting nutrients (e.g., Traber 2007), both within your digestive tract and in your cells (some of which we know are toxic at high levels), across individuals with significant physiological and environmental variation, the multivitamin game seems ever more absurd.
Neither the results of this study nor the reason for conducting it in the first place are new phenomena. Why do we continue to be obsessed with vitamins despite mounting evidence that they do nothing for us? Apparently in our consumerist sound-byte world, we still want something for nothing: easy money (whose devotees will certainly persist despite the lessons of the recent financial collapse), easy love-life, easy weight loss, and easy health. In fact, despite what the marketers have so convincingly told us, there are no shortcuts. But although logic and science demonstrate otherwise, the nutritional reductionists will continue think the magic pill is just around the corner, as we break down food and identify more and more of the molecules that add up to a particular organic being.
The true vitamin believers will probably argue though that absence of evidence is not the same as evidence of absence. It is a weakness of studies that do not find statistical differences that it is often unclear whether or not the result was due to biological nonsignificance, or faulty methodology. Unfortunately, for over half the participants in this study, the data collected were self-reporting data of vitamin use, which may not be reliable (Kuetting et al., 2008). In this case, the enormous sample size should probably be enough to compensate for less-than-precise data, if any real effects of supplements were at all strong.
Naysayers may also point out that the study just looked at prevention of a few diseases, when other possible benefits of vitamin-intake, say overall health, or prevention of colds or other minor viruses, are ignored. The problem here is that the nutritional knowledge contributing to the design of supplements clearly just scratches the surface of the actual nutritional complexities. We know enough to know the vast amount we don’t know – so believe what you want, but realize that there won’t be science to support it anytime soon.
So, tossing out the organic cereal in favor of traditional brands would be an extreme reaction, because it assumes that processed grain with a dozen nutrients thrown back in is as good as what originally came out of the ground. That misses the point. If you want real nutritional completeness that you feel may be lacking from your diet, there is no easy magic pill. All you can do is reduce your consumption of processed foods, organic or not, in favor of food that pretty much looks the same as it did before mega-agribusiness started messing with it. Which admittedly can be tough these days, if you don’t live on a farm.
Kuetting, B., Uter, W., & Drexler, H. (2008). The association between self-reported acrylamide intake and hemoglobin adducts as biomarkers of exposure. Cancer Causes & Control, 19(3): 273-281.
Neuhouser, M. L., Wassertheil-Smoller, S., Thomson, C., Aragaki, A., Anderson, G. L., Manson, J. E., et al. (2009). Multivitamin use and risk of cancer and cardiovascular disease in the women’s health initiative cohorts. Archives of Internal Medicine, 169(3): 294-304.
Traber, M.G. (2007) Vitamin E regulatory mechanisms. Annual Review of Nutrition, 27:347-362.