Heli J. Roy | 4/21/2005 9:18:00 PM
LSU AgCenter nutritionist Dr. Heli Roy recently examined the controversy over dietary herbal products containing caffeine and ephedra. The products are popular for weight loss, but not necessarily safe.
Since the enactment of the Dietary Supplement Health and Education Act by Congress in 1994, dietary herbal supplements have been regulated as foods with the presumption of safety.
The act also created an Office of Dietary Supplements within the National Institutes of Health. More than half of the adult population in the United States consumes some type of dietary supplement. The sale of herbal dietary supplements in the United States has increased dramatically. Sales were approximately $5 billion in 1999. The growth of the herbal-supplement industry continues at approximately 30 percent per year.
Caffeine and ephedra (C&E) from herbal sources are classified as dietary herbal supplements and have become popular in weight loss products. Ephedrine or products containing combinations of ephedrine and caffeine are not approved in the United States as drugs for weight loss. In fact, an estimated three billion doses of ephedra-containing supplements were sold in 1999.
"The unregulated sale of ephedra-containing supplements, however, has become controversial because of reports of adverse events," Roy said, explaining, "Ephedra has been linked to several deaths, myocardial infarctions, cerebrovascular strokes and seizures, and there have been more than 18,000 consumer complaints reported to a manufacturer of ephedra-containing dietary supplements."
The Food and Drug Administration is reviewing the status of ephedra. The supplement is banned from the National Football League (NFL), National College Athletic Association (NCAA) and the Olympics, but not from major league baseball. Athletes have used over-the-counter stimulants containing ephedrine or its related alkaloids to enhance athletic performance.
Previous studies show that those who have caffeine and ephedra before an exercise session have an altered cardiovascular response during exercise and an increase in blood pressure. The higher blood pressure puts increased demand on the whole cardiovascular system during exercise. C&E products are sold to increase metabolism and to cause weight loss.
Drs. Frank Greenway, Lilian de Jonge and Steven Smith from the Pennington Biomedical Research Center tested a commercial caffeine and ephedra product in three phases. The first phase tested the efficacy of the product in raising metabolic rate compared with a placebo. The second phase was a double-blind, placebo-controlled randomized 12-week trial testing the safety and efficacy of the herbal caffeine and ephedra product. The third phase observed the safety and weight loss over six months in all participants.
Up to 40 overweight male and female subjects completed the three phases of the study. Subjects who completed phase 3 were given a gift of an additional three-month supply of the herbal dietary supplement product for home use.
The subjects who took caffeine and ephedrine had a significantly higher resting metabolic rate and lost significantly more weight than those who were on a placebo (7.7 pounds versus 1.76 pounds). There was no significant difference in blood pressure, total cholesterol, HDL cholesterol, LDL cholesterol or triglyceride between groups.
The caffeine and ephedra group lost more body fat than those on the placebo (7.9 percent versus 1.9 percent). There were no serious adverse events and no evidence of toxicity on physical examination, urinalysis or blood testing at the end of the treatment. Evidence from 52 previous trials, however, supports the conclusion that the use of ephedrine, ephedrine plus caffeine or ephedra plus caffeine is associated with two to three times the risk of nausea, vomiting, psychiatric symptoms such as anxiety and change in mood, autonomic hyperactivity and palpitations.
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