June 11, 2002 -- Although supplements containing ephedra have been circumstantially linked to dangerous cardiovascular effects, results of a controlled trial reported in the June issue of the International Journal of Obesity suggest that the combination of ephedra and caffeine may safely aid weight loss. Extrapolating these results to off-the-shelf supplements, however, could be risky.
"It is surprising how people's minds can be so made up based on anecdotal reports," lead author Carol N. Boozer, DSc, tells WebMD. "You can't determine cause and effect from this kind of information."
In this six-month, double-blind trial, 167 subjects (body mass index [BMI] 31.8 + -4.1 kg/m2) were randomized to placebo or herbal treatment at two outpatient weight-control research units. Herbal treatment consisted of ma huang and kola nut supplement containing 90 mg/day ephedrine alkaloids and 192 mg/day caffeine.
Compared with placebo, herbal treatment significantly decreased body weight (-5.3+177;5.0 vs. -2.6+177;-3.2 kg, P < 0.001), body fat (-4.3 + 177;3.3 vs. -2.7+177;2.8 kg, P = 0.020) and LDL-cholesterol (-8±20 vs. 0+177;17 mg/dl, P = 0.013), and increased HDL-cholesterol (+2.7+177;5.7 vs. -0.3 + 177;6.7 mg/dl, P = 0.004).
"Our study showed...that healthy, overweight people who took our herbal product lost more weight and body fat than did a similar control group," Boozer says. "They didn't experience any significant adverse event."
Herbal treatment did not significantly increase cardiac arrhythmias ( P > .05), but it did produce small changes in blood pressure (+3 to -5 mm Hg; P .05) and increased heart rate (4+177;9 vs. -3+177;9 beats per minute; P < .001). Subjects receiving herbal treatment reported increased dry mouth, heartburn, insomnia and decreased diarrhea. Irritability, nausea, chest pain, palpitations and numbers of subjects withdrawing from the study were similar in both groups.
Neal L. Benowitz, MD, and Christine A. Haller, MD, authors of an earlier University of California, San Francisco, study linking cardiac problems to ephedra use, remain unconvinced by Boozer's trial. "The adverse effects that occur from dietary supplements can be catastrophic, but they are uncommon," Benowitz tells WebMD. "The likelihood of detecting rare events in small trials like this one is virtually nil."
Haller adds that this study did not use off-the-shelf supplements, which vary widely in active ingredients. "I really don't think you can use this as a study to invoke the safety of dietary supplements," she tells WebMD. "This is just not what people out there are taking. Until we know about the other ingredients, we can't speak to safety."
Science Toxicology and Technology Consulting in San Francisco supported Boozer's study.
Int J Obesity. 2002;26:593-604
Reviewed by Gary D. Vogin, MD
Medscape Medical News © 2002 Medscape
Cite this: Laurie Barclay. Ephedra Plus Caffeine Safely Lowers Weight in Controlled Trial - Medscape - Jun 11, 2002.