Dear Dr. Narda, my friend Rose is a chiropractor for humans (though she treats animals at night in her office and she might not want me to divulge that information since it’s not entirely legit.) I love Rose dearly but she’s always telling me to take this, that, or the other supplement, whether it’s to thicken my hair, treat my hot flashes, or help me sleep. It seems as though she’s got a “natural” pill not only for anything that ails me, but also my pooch, Roger. Since I was a nurse practitioner prior to retirement, I’m accustomed to seeing scientific papers on the products I’d prescribe, but when I ask Rose for substantive literature, she refers me to the company’s sales representatives. How am I supposed to rely on them when they have what I guess is called, nowadays, “skin in the game”? Signed, Regina and Roger Rooted in Rochester.
Dear Regina and Roger, you inquired as to whether or not you can “trust” dietary supplements, and the answer is, “it’s hard to tell”. Many like you wonder what’s in the bottles and whether their contents are safe. For that matter, we often don’t even know if they are effective. Trusting in a practitioner like your chiropractor friend can only go so far. We need real data from real investigations. The problem is, those data are difficult to come by. Fortunately, more are asking tough questions about the supplements they are taking or, for practitioners, what they are selling or prescribing.
You may be interested in watching the exposé by the PBS show “Frontline” called, “Supplements and Safety” (January 19, 2016). This eye-opening investigation showed how manufacturers can be clueless about the science or quality of the products they are selling. They reported on the “revolving door” phenomenon between government regulators and supplement manufacturers and how hard it is for even physicians to get the U.S. Food and Drug Administration (FDA) to take action.
In another investigation, researchers from the University of Guelph found startling safety and quality problems in 44 herbal products with 30 species of herbs, and 50 leaf samples from 42 herbal species. They found that nearly 60 percent of the products tested contained plant parts not listed on the label. Even in the 50% of items that did include DNA from botanicals listed on the label, a third had undisclosed contaminants and/or fillers.
The results of these herbal substitutions can be serious or at the very least, surprising. For example, one product labeled as St. John’s wort contained no St. John’s wort DNA barcodes and only evidence of senna, an herbal laxative. Undisclosed plant fillers posed another hazard: DNA barcoding identified substances such as rice, soybean, and wheat, the latter posing problems for those with gluten sensitivity.
So, Regina and Roger, I really can’t say that you can trust just anyone’s, even Rose’s, word on whether dietary supplements are safe or effective. We need to find ways to strengthen requirements for proven safety and effectiveness prior to products reaching the market. Otherwise, it’s anyone’s guess.