When I shared this story with colleagues, family and friends, they all basically asked me the same question. Did I ask the gentleman to leave or to refrain himself? I did not. In fact, I chose instead to respond to his concerns. I believe that no one has all the facts when it comes to supplements. That's why I love Mark Twain's quote, "It ain't what you know that gets you into trouble. It's what you know for sure that does."
I think vigorous and rigorous debate is helpful and necessary, and I wish there were more of it regarding the growing usage of all kinds of supplements.
My common retort to people who question the information I provide is to ask them to offer up alternative information in the form of published studies. I don't do this to put them on the defensive; rather, I do it because I genuinely want to stay on top of the science as best as I can. Yet, every time I've asked for such studies, when the person actually bothers to follow up, I am delivered studies that show that increased intake of one supplement or another increases the blood level of the consumed product. I also get a lot of fruit fly and animal studies.
When I question the validity of such studies and ask for any studies published in a peer review journal, that are randomized double-blind controlled studies, the typical response is that it is too expensive to do such elaborate studies demonstrating improved health or decreased illness with supplements. I respectfully disagree because I read study after study that meet such criteria and that fail to deliver the promised results. For example, about a month ago, such a study was done at Harvard to test the usefulness of Saw Palmetto in reducing symptoms for enlarged prostate. The study failed to show Saw Palmetto having any benefit over placebo. So, please don't believe people who tell you that such studies can't be done because they are being done but the results don't support the marketers' agendas.
Getting back to my heckler, my primary response to him was that all the studies I was quoting were generally large studies containing tens of thousands of participants. Several studies indicated minor increases in death rates among supplement users. I don't treat these studies like gospel because they also have their flaws. I explained that it's not the death rates that bother me as they were mainly insignificant. It's that none of these studies show any real benefits associated with popping extra pills as opposed to eating a healthy diet. Except for macular degeneration, a eye disease, they never do.
I like to explain to my audiences in general that the body of knowledge is so large and still expanding, that it is virtually impossible for any person to stay abreast of all the studies, large and small, reliable and unreliable, providing new information or rehashing old information, confirming prior studies or refuting them, etc. Yet, failure to know everything is not a reason to wear blinders and naively follow the advice of people who hustle their assortment of products.
I declare right here and right now that I am still in the process of learning, gathering information, sifting through thousands of old and new studies, and sorting through sometimes conflicting information. I have a growing bias against supplementation, but have reached no definitive conclusions. I do believe that some hold medicinal properties otherwise difficult to obtain by diet alone. Still, I believe as Hippocrates said some 2,500 years ago, "There are two things. To know and to think you know. To know is science and to think you know is ignorance." Please forgive my ignorance as it is not intended. I search for the truth for myself, my family, my friends, my patients, and ultimately, society at large.
I do, however, have a problem with this type of double-talk statement apparently made by Duffy MacKay, vice president of scientific and regulatory affairs for the Council for Responsible Nutrition in reference to a study that showed that certain does of selenium supplementation can increase risk of diabetes and cancer:
So instead of discouraging debate, let's embrace it in a respectful and open-minded manner. However, let's not let emotion cloud our judgment and confuse pseudo-science with good science. Let's not let hucksterism rule that day. I'm open to information that proves inaccurate anything I write. I really do want to get to the truth and facts. Please contact me at firstname.lastname@example.org if you have anything to share.
By the way, my heckler came up to me after the lecture and said he enjoyed it. So did I.