This article, by Dr Irene Berman-Levine, is adapted from one of her recent Newsletters. This weekly free newsletter, Dr. Irene's Nutrition Tidbits, helps you understand the confusing world of nutrition and motivates you to choose healthy foods. You can sign up for the newsletter by clicking here.
Dr Irene has also packaged many of her newsletter articles into a book, which you can order for US$16 by clicking here . Robert Griffith, Editor.

Your bottle of supplements may not contain all it says on the label. According to testing by ConsumerLab.com, one in four supplements in the United States lacks the promised ingredients or has other serious problems. ConsumerLab.com is a privately held company that completes independent evaluations of products that affect health and nutrition and provides consumer information.

I contacted Tod Cooperman, M.D., the President of ConsumerLab.com this summer when I was researching a reader's question on fish oils. I'd discovered their study identifying that 6 of 20 fish oil supplements tested failed their review and wanted more information. Dr. Cooperman informed me at that time that their new book, "ConsumerLab.com's Guide to Buying Vitamins & Supplements: What's Really in the Bottle?" was going to be released soon. I received a copy last week and tonight I finally had a chance to look at it. The book is a wealth of information, and can be purchased in bookstores or online from ConsumerLab.com (see link below).

This article will concentrate on a ConsumberLab.com study that was just released. It focused on 3 "muscle enhancement supplements": creatine, hydroxy-methylbutyrate (HMB), and glutamine. Their review includes results for 23 creatine, HMB, and glutamine supplements, including 16 tested in the Review and 7 others that recently passed the same evaluation through a Voluntary Certification Program. Even though the term "muscle enhancement supplement" is used, I want to clarify immediately that I do NOT endorse the use of these supplements. They have not been proven safe for many populations and their muscle enhancing properties are specific to certain situations. For example, creatine has no documented benefit in purely aerobic exercises. There are small studies showing it may be of benefit, but these are in very specific situations, such as trying to improve tolerance to exercise in patients with congestive heart failure and improving muscle strength in people with muscular dystrophy. Some advertisements may claim increase in muscle size but this is believed to be due to increased water retention in the muscle and not to an increase in lean body mass.

My warning that the everyday athlete will not find benefit in using creatine is not just my opinion. A review of scientific literature¹ concluded that creatine may be marginally beneficial to professional athletes, but not to others. Its benefit is only in repetitive, brief, high-intensity sports activities. The everyday athletes, even those competing in high school or college, are not professional athletes and should not take the health risks of these supplements.

What I am trying to point out in reporting ConsumberLab.com finding is that those who still insist on using these supplements may not be getting what they think they paid for. Only half of the creatine products passed the review. Problems were most common among newer delivery forms, particularly creatine liquids - one of which was essentially sugar water with only 1% of the claimed creatine.

Testing by ConsumerLab.com of creatine supplements found problems with the majority of products sold in liquid, effervescent and chewable forms. Problems were not found among standard creatine "powder" products. One liquid product contained virtually no creatine and was contaminated with a creatine breakdown compound despite claiming to contain "100% Stable" and "Pure" creatine and boasting "Builds Lean Muscle Mass." The latter claim is not an approved FDA claim so the supplement does not meet FDA labeling requirements. An effervescent product also failed for containing creatinine contamination and a chewable wafer product failed for containing less than 90% of its claimed creatine.

Two other types of supplements tried by people to enhance muscle - HMB and glutamine - were also tested. HMB may (and notice that the ConsumerLab.com report say MAY) help increase muscle mass and strength with weight training. There is only weak evidence from small studies, and more research is needed on both effectiveness and safety before I would ever recommend it. At least if it is someday proven effective, you might be getting what you paid for. All HMB products passed testing except for one that contained less than 90% of the claimed amount.

All of the glutamine products were found to contain their claimed amount, but one failed the review because it did not follow FDA labeling requirements. Specifically, it made unapproved claims to combat free radical damage from degenerative diseases, act as a cellular detoxifier, and increase growth hormone release. It also lacked the required disclaimers that the FDA had not evaluated its claims and that the product "is not intended to diagnose, treat, cure or prevent any disease." In addition, it did not provide information in a standard Supplements Facts panel.

Please note that the value of glutamine supplementation in exercise performance has NOT been demonstrated - although it may reduce the incidence of infection in athletes who are over-training.