03.03.10
A carcinogenic form of chromium—hexavalent chromium—is present in some dietary supplements, according to new tests by ConsumerLab.com, White Plains, NY. Hexavalent chromium was found in two popular weight loss products and a chromium supplement, while three other chromium-containing supplements selected for testing were not contaminated. ConsumerLab.com also found lower amounts of green tea than claimed in some weight loss supplements and noted concern for potential side effects from products containing high amounts of caffeine or other stimulants.
Chromium, which is important for insulin function, is often used in weight loss supplements due to research suggesting modest weight loss benefit—although the evidence is mixed. Hexavalent chromium, which was at the center of the movie Erin Brockovich, should not normally be found in supplements. Legal limits have not been established for the amount of hexavalent chromium in supplements, but the state of California is considering an aggressive public health goal limiting hexavalent chromium in drinking water to only 0.06 ppb—about 0.12 mcg per day. The California limit is based on a one in one million lifetime cancer risk extrapolated from studies in mice.
ConsumerLab.com found that one widely sold weight loss pill delivered 26.4 mcg of hexavalent chromium per day, 220 times the maximum amount one could be exposed to from daily intake of water under California’s proposed limit. A chromium supplement delivered 10.9 mcg in a daily serving and another nationally known weight loss supplement contained up to 3.2 mcg per daily serving. The contaminant was confirmed in three independent laboratories using blinded samples. Although no legal limit has been established, ConsumerLab.com requires that the chromium in supplements be 99.9% pure. Its tests showed these three products contained 6%, 2%, and 0.64%, respectively, of their total chromium as hexavalent chromium, all exceeding ConsumerLab.com’s limit. The specific risks associated with these amounts are not known, but it seems prudent to avoid such exposure, particularly as other chromium-containing products are available that passed ConsumerLab.com testing.
Other quality problems revealed by ConsumerLab.com included two supplements providing less green tea than listed and a supplement with FDA labeling violations. In fact, due to the variety of quality problems discovered, all five of the weight loss supplements selected by ConsumerLab.com with listed amounts of green tea failed testing. ConsumerLab.com also noted the potential risks (including insomnia, tremors, nausea, and headache) posed by weight loss supplements with high amounts of caffeine (three of which provided 600 mg per day – equal to about 15 cans of cola). Potential cardiovascular risks were also raised with a product combining caffeine with synephrine (from the ingredient bitter orange) and with two products containing the ingredient yohimbine, an erectile dysfunction remedy.
ConsumerLab.com’s reviews are available in two online reports, one focusing on Chromium Supplements and the other on Weight Loss Supplements (Green tea, 7-keto DHEA, and Stimulant Blends). The reports provide results for seventeen products. Thirteen supplements were selected by ConsumerLab.com and four others are included in the reports for having passed the same evaluation through ConsumerLab.com's Voluntary Certification Program. Also listed is one product similar to one that passed but sold under a different brand name. The reports are the final two in a three-part series relating to weight loss and slimming supplements—a $1.7 billion sales category in the U.S. in 2008 according to Nutrition Business Journal. A report on CLA Supplements for Slimming was released last month. The reports provide evaluations, ingredient comparisons, and expert tips on buying and using these supplements.
