By Scott Stevenson, PhD, Lac
Are you gullible, or are you a skeptic? When it comes to nutritional supplements, do you go by your gut and listen to your intuition, or are you a “show me the data” kind of guy? If your mother said it was fine to take, would you trust her above all other sources? Does FDA approval really make a supplement safe? Just what is a dietary supplement anyway?
Let’s take a look at the ins and outs — the “anatomy,” so to speak — of a dietary supplement, and what it may take to know if your supplements are really working. In the first installment of this article, I’d like to examine who you should trust in gathering your information. Part Two will be about taking action and becoming your own supplement know-it-all, your own personal “supplement guru.” It won’t be easy, but if you’re curious, meticulous and motivated to improve your physique, you already have all the tools you’ll need.
What Is a Dietary Supplement?
With apologies to readers in other countries, I’ll focus on the state of dietary supplements here the USA. The Dietary Supplement Health and Education Act (DSHEA) of 1994 states that a “dietary ingredient” in a dietary supplement can be a concentrate, metabolite, constituent or extract of a vitamin, mineral, herb, botanical, amino acid or “a dietary substance for use by man to supplement the diet by increasing the total dietary intake (e.g., enzymes or tissues from organs or glands) (1)” or simply a concentrate, metabolite, constituent or extract thereof (2). Basically, the sky’s the limit for ingredients in dietary supplements in the Land of the Free. But according to DSHEA, we also leave a lot of trust in the hands of those selling supplements:
“A firm is responsible for determining that the dietary supplements it manufactures or distributes are safe and that any representations or claims made about them are substantiated by adequate evidence to show that they are not false or misleading. This means that dietary supplements do not need approval from FDA before they are marketed. Except in the case of a new dietary ingredient, where pre-market review for safety data and other information is required by law, a firm does not have to provide FDA with the evidence it relies on to substantiate safety or effectiveness before or after it markets its products (1).”
This leaves us with many sources of authority in knowing what to expect from a given supplement: The company selling it, scientists and the scientific literature, our peers in the gyms, including the veterans and gurus of the bodybuilding community and, of course, ourselves, including our accumulated knowledge, intuition and experience.
Trusting the Manufacturer
How can you know when to put your faith in the purveyors of dietary supplements, and be certain that they have your best interest in mind? New companies can be as good or even better at providing high quality ingredients as the larger, more established companies, but there’s also something to say for long-term marketplace survival. A new upstart company may be out for a quick buck with a supplement gimmick, or they may realize that their products must outperform the giants and thus they work overtime to ensure product quality. I’m always impressed with a company that takes time for the little guy, providing money-back, no-questions-asked guarantees, personal email responses, prompt product returns, and certificates of analysis for all of their products.
If a company sells a product it claims is backed by scientific research, can you find and read those studies (and better yet, are they well done)? It’s also important to know that if a company has a “proprietary blend” of several substances listed among a product’s ingredients that those substances need only be listed in order of predominance by weight in the blend, and that the actual amounts of each need not be listed (3). For instance, if you’re concerned about total caffeine content in your diet, will the manufacturer reveal the caffeine content in its proprietary blend?
Who’s Really the Expert?
In bodybuilding circles, the relative merit of prestigious degrees in nutritional biochemistry, exercise physiology, or molecular biology compared to years in the trenches is a frequent point of contention. Both have their place, but it can get confusing when lifting veterans speak as scientists, perhaps out of turn, or simply when science is interpreted casually. A famous example of science not matching “real life” as we know it now, and one frequently miscited as a knock on “scientists living in ivory towers,” is the 1977 ACSM Position Statement on the Use and Abuse of Anabolic-Androgenic Steroids (4). The Position Statement reads, “There is no conclusive scientific evidence that extremely large doses of anabolic-androgenic steroids either aid or hinder athletic performance.” Naturally, that position statement has since been modified — to a degree (5) — and certainly today scientists know this isn’t the case (6). However, what’s often missed in criticizing that old document is that in 1977, that statement seemed perfectly true according to the available literature and how those authors define “conclusive scientific evidence.” In other words, the authors’ conclusions were factually correct, if understood from an historical scientific perspective.
Show Me the Science
How often have you heard “I read a study somewhere …”? Sure, you can trust in that person’s authority, but realize that, at best, you’re getting “sloppy seconds” information-wise. A published study is the report of an experiment that has first been designed and interpreted by the authors (with peer-review and editorial input) before it’s filtered through the perspective the person conveying that information to you. If your source is a news article in the lay press, your chances of reading an unbiased report are dismal at best. Ask for the reference, find the study and read it yourself (see below), if you think it really matters.
Pubmed is a great place to start when searching for exercise and nutrition-related scientific reports and reviews.
Beware the Broscientist
The “broscientist,” in case you don’t know, bro, is a harbinger of metabolic and physiologic bodybuilding knowledge presented as undeniable scientific “fact,” that mysteriously is often entirely unsubstantiated by scientific evidence (7). Basically, broscience is what some guy heard form another guy that got passed along enough times to harden the information as incontrovertible proof in the broscience archives. One of my favorite broscience “bodies of literature” concerns the effects of creatine monohydrate (CM) supplementation on muscle metabolism. You can still read that CM supplementation raises muscle ATP concentrations at rest (feel free to google this one), which is clearly not the case (8-11). Instead, stores of creatine and creatine phosphate are elevated, enhancing the use of creatine phosphate as a fuel during high intensity bouts (12). The important point here is that claims about resting muscle ATP concentration are clearly of a scientific nature, and thus the (bro)scientist would, to be most trustworthy, need scientific data to back up his claims. Suspect broscience when the science seems thick and the citations are thin.
I hope you’ve become a bit more skeptical in considering how you gather your knowledge of dietary supplements and their workings. In the Part Two of this article, I’ll focus on actively pursuing the “truth” about a dietary supplement’s effectiveness and how you can start becoming your own “supplement guru.”
1. Food and Drug Administration. Overview of Dietary Supplements. 2011 [Accessed 8.23.11]; Available from: http://www.fda.gov/Food/DietarySupplements/ConsumerInformation/ucm110417.htm#what.
2. Office of Dietary Supplements, N.I.o.H. Glossary in Dietary Supplement Ingredient Database. 2011 [Accessed 8.23.11]; Available from: http://dietarysupplementdatabase.usda.nih.gov/glossary.html.
3. Office of Dietary Supplements, N.I.o.H. Background Information: Dietary Supplements. 2011 [Accessed 8.23.11]; Available from: http://ods.od.nih.gov/factsheets/dietarysupplements/.
4. American College of Sports Medicine, Position statement on the use and abuse of anabolic-androgenic steroids in sports. Medicine and Science in Sports, 1977. 9(4): p. xi-xii. http://www.ncbi.nlm.nih.gov/pubmed/604712
5. American College of Sports Medicine, Position statement on the use of anabolic-androgenic steroids in sports. Medicine and Science in Sports, 1987. 19(5): p. 534-539. http://journals.lww.com/acsm-msse/Citation/1987/10000/Position_Stand_on_The_Use_of_Anabolic_Androgenic.23.aspx
6. Bhasin, S., et al., The effects of supraphysiologic doses of testosterone on muscle size and strength in normal men. N.Engl.J Med, 1996. 335: p. 1-7.
7. Urban Dictionary. Broscience. 2011 [Accessed 8.25.11]; Available from: http://www.urbandictionary.com/define.php?term=broscience.
8. Febbraio, M.A., et al., Effect of creatine supplementation on intramuscular TCr,metabolism and performance during intermittent, supramaximal exercise in humans. Acta Physiol Scand, 1995. 155: p. 387-395.
9. Harris, R.C., et al., Elevation of creatine in resting and exercised muscle of normal subjects by creatine supplementation. Clin. Sci.(Colch). 1992. 83: p. 367-374.
10. Odland, L.M., et al., Effect of oral creatine supplementation on muscle [PCr]and short-term maximum power output. Med Sci.Sports Exerc., 1997. 29: p. 216-219.
11. Vandenberghe, K., et al., Caffeine counteracts the ergogenic action of muscle creatine loading. Journal of Applied Physiology, 1996. 80(2): p. 452-7. http://www.ncbi.nlm.nih.gov/pubmed/8929583
Casey, A. and P.L. Greenhaff, Does dietary creatine supplementation play a role in skeletal muscle metabolism and performance? The American Journal of Clinical Nutrition, 2000. 72(2 Suppl): p. 607S-17S. http://www.ncbi.nlm.nih.gov/pubmed/10919967