Ephedra Taxes Heart During Exercise, AHA Urges FDA Ban

April 28, 2003

4 Min Read
Ephedra Taxes Heart During Exercise, AHA Urges FDA Ban

Ephedra Taxes Heart During Exercise, AHA Urges FDA Ban

SAN DIEGO--Additional research has emergeddemonstrating the potential for adverse cardiovascular events from taking anephedra/caffeine combination before exercise. Tasha P. Ballard and Matthew D.Vukovich, Ph.D., FACSM, both from South Dakota State University in Brookings,presented a study at the American Physiological Society's (www.the-aps.org)Experimental Biology 2003, held here April 11 to 15, demonstrating that thecombination of ephedra and caffeine, taken prior to exercise, places greaterstress on the heart than placebo by affecting the cardiovascular system before,during and after exercise.

Vukovich conducted a resting study prior to his exercise studyand determined ephedra/caffeine places additional stress on the cardiovascularsystem even without exercise. "During the resting study, we saw a23-percent increase in heart rate and 10-percent increase in bloodpressure," he told INSIDER. "The concern was, while exerciseincreases heart rate and blood pressure and caffeine/ephedra increases heartrate and blood pressure, what happens when people take them together, which mostpeople do?"

To determine what would happen, Ballard and Vukovich randomlyassigned 10 healthy, college-age subjects (five men and five women) who werefree of caffeine to either a one-time dose of placebo or a combination of 150 mgof caffeine plus 20 mg of ephedra. After a week washout period, the subjectsreversed regimens. Researchers recorded the subjects' key physiologicalmeasurements--blood pressure, VO2 (oxygen consumption, which helps researcherscalculate resting metabolic rate and caloric expenditure) and hypersensitiveresponse--prior to and 30 and 60 minutes after supplement administration.

Results indicated hypersensitive response was higher at 60minutes rest in subjects that received the combination, and remained higher at30 and 60 minutes of exercise. However, this increase does not warrant usingephedra/caffeine for weight loss, according to Vukovich. "It's only a 100kcal difference--equivalent to walking for 15 minutes," he said. "Thenyou have to look at the risk-to-benefit ratio. Granted, it may increase restingmetabolic rate, but you get a greater increase in heart rate and blood pressure,and overweight individuals have high blood pressure as it is."

In addition to the increased hypersensitive response,researchers found those taking the supplements exhibited higher systolic bloodpressure during rest. Mean arterial pressure (the driving pressure of blood flowthrough the body) measured higher in the treatment group, as well.

"Based on the results we've gotten out of our lab, to methere is no reason to take [ephedra-based supplements]," Vukovich said.

Michael McGuffin, president of the American Herbal ProductsAssociation (AHPA), noted that while Vukovich's study demonstrated the effectslikely to be seen from using the available ephedra/caffeine supplements on themarket, the research did not take into account how big a role each of thecomponents played in affecting cardiovascular function. "We don't know whatrole ephedra played in this, compared to what role caffeine played inthis," he said. "If these authors, or the journal in which theypublish, intend to make this an 'ephedra is bad' news story, there's a problemwith that. Caffeine has exactly the same effects [as ephedra]. The next studyshould compare caffeine alone, ephedra alone--then we'd see a meaningfulscientific inquiry that would be useful for better understanding thephysiological effects of ephedra."

In additional ephedra news, due to the potentially dangerouscardiovascular side effects of ephedra consumption, the American HeartAssociation (AHA) submitted comments to the Food and Drug Administration (FDA)April 3 urging a ban of ephedra-based supplements. Robert O. Bonow, M.D., AHApresident, stated the evidence against ephedra supplements indicates the dangersare greater than the potential benefits, and while consumers who use ephedra-basedsupplements may think they are doing something healthy, they may be puttingthemselves at risk.

Bonow stated the only way to protect consumers from these"dangerous" supplements is to ban them completely."Unfortunately, experience tells us that there is a tendency for the publicto ignore warning labels and dosage information," he said. "Because ofthe uncertainty surrounding these products, we believe it is necessary tocompletely eliminate that risk."

McGuffin noted that consumer responsibility plays a large rolein the debate surrounding ephedra. "Some of the concern is that ephedra isa physiologically active stimulant," he said. "That means it shouldbear a warning label. The Dietary Supplement Health and Education Act [DSHEA]is, on its face, a consumer right-to-know law. We continue to believe consumershave a right to know and to make choices, which does involve someresponsibility. Consumers need to read the label and believe the label. ...That's our challenge--to make consumers believe that a warning label means'warning.'"

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