Multi-Ingredient Caffeine Products Easily Top Adverse Event List, Study Finds
This article was originally published in The Tan Sheet
Executive Summary
The vast majority of adverse events that can be attributed with near certainty to a supplement involve weight-loss or energy-enhancing products, a study conducted by Christine Haller, M.D., finds
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The vast majority of adverse events that can be attributed with near certainty to a supplement involve weight-loss or energy-enhancing products, a study conducted by Christine Haller, M.D., finds. Haller, who is an assistant professor of medicine at the University of California, San Francisco, and the assistant medical director of the California Poison Control System, San Francisco Division, spoke at the United Natural Product Alliance's Jan. 11 seminar on implementing the AER bill recently signed into law by President Bush (see 1 (Also see "Experts Give AER Prep Course, Discuss Potential Potholes At UNPA Seminar" - Pink Sheet, 29 Jan, 2007.)). Haller is an expert on botanical stimulants and has published numerous studies on the ingredients (2 (Also see "Bitter Orange/Caffeine Combinations Could Cause Adverse Events – Study" - Pink Sheet, 19 Sep, 2005.), p. 11 and 3 (Also see "Recommended Ephedra/Guarana Doses Show Harm in Haller Study" - Pink Sheet, 20 Jun, 2005.), p. 17). At the seminar, Haller discussed the results of an ongoing prospective surveillance project she is working on that seeks to track and report in real time dietary supplement adverse events reported to a poison control center. The study, which started at the beginning of 2006, is supported through a contract with FDA's Center for Food Safety and Applied Nutrition, and Haller et al. provide FDA with quarterly summary reports of the adverse event calls received by the center. As part of the study, the reported adverse events are reviewed by an expert panel to determine the likelihood an event was caused by the suspect dietary supplement. In 90 percent of the cases the panel felt it was "very likely or certain" an adverse event was caused by a supplement, the suspect product was indicated for weight-loss and/or energy-enhancement, the study found. According to Haller, 275 calls involving dietary supplements were made to the San Francisco office of the state's poison control network in the first 12 months of the study. Of these, 141 (41%) involved symptomatic exposures. More than half of the symptomatic events were related to the use of a multi-component caffeine product, she said. Yohimbine multi-ingredient supplements were the second most frequently associated products, according to the study. Single-ingredient caffeine products were third highest. Notably, of all the reported events only five involved overdose or misuse, Haller said. "So, most of these do represent recommended use of the product." Haller and her colleagues have several specific concerns regarding multi-ingredient caffeine and multi-ingredient yohimbine products. The products rarely quantify their caffeine levels, and many of the products include significant doses of caffeine per serving, Haller said. For example, Cytodyne's Xenadrine NRG 8 Hour contains 238 mg of caffeine per serving, the researchers found. A regular-sized cup of coffee has 80 mg, according to Haller. Children or "any caffeine-naive person could have a significant response to this degree of caffeine," she said. These supplements are often marketed to body-builders and athletes, she said. "I'm not aware of any studies that have shown it is safe to take caffeine with yohimbine and go work out," Haller observed. "When you combine sympathomimetic drugs that act in different ways [such as caffeine and yohimbine], you have a synergism that can develop .... Your body can't compensate well when you're doing that," she said. They are also commonly marketed to populations with significant health concerns, such as hypertension, diabetes and obesity, that do not tolerate caffeine well, Haller said. Additionally, the multi-ingredient caffeine products "are quite colorful and attractive to little toddlers," she observed. "If they just had a child-resistant top, it would be better," Haller opined. Another concern Haller identified is that for some products - such as VPX's RedLine Fat Incinerator , which was involved in a number of events - a variety of doses and formulations exist, which could confuse consumers and lead to accidental overdose. Haller noted she is currently involved in a study to analyze the amounts of caffeine and yohimbine in products sold to consumers. Results from the study may be released "in a year or so," she said. - Katia Fowler |