A combination of caffeine and the herb ephedra alters cardiovascular response prior, during and after exercise, according to researchers who will report on their findings at an Experimental Biology meeting next week.
The team say their results may explain the interaction of the two compounds and show how a product containing both can provide the 'final boost'.
Since the apparently ephedra-related death of Baltimore Orioles pitcher Steve Bechler earlier this year, supplements containing the herb have been under close scrutiny. The Chinese herb is attractive to athletes because it provides an energy 'boost' during games, and is believed to stimulate weight loss.
Researchers from the South Dakota Health Promotion and Research Program at South Dakota State University have now examined how ephedra and coffee could impact health. There has previously been disagreement among scientists over the safety of combining these two compounds.
For the study, 10 caffeine-naïve men and women were studied at rest, during exercise, and recovery after the ingestion of either a placebo or 150mg caffeine/20mg ephedra. Key physiological measurements (blood pressure, VO2, hypersensitive response) were made prior to, and 30 and 60 minutes following the administration of supplements.
They found that hypersensitive response was higher at 60 minutes rest in caffeine/ephedra subjects and remained higher at 30 and 60 minutes of exercise. Additionally, those taking the supplements registered higher systolic blood pressure during rest. Mean arterial pressure also measured higher in the caffeine/ephedra group.
Conclusions from the small study suggest that ingesting caffeine and ephedra prior to exercise will alter the cardiovascular system by increasing hypersensitive response prior, during, and after exercise, and systolic blood pressure before exercise. The higher rate pressure indicates greater demands on the heart when individuals consume caffeine and ephedra.
The Food and Drug Administration is currently reviewing the status of ephedra, which has been linked to almost 100 deaths, including high school and college athletes who have collapsed during games or practice. The supplement is banned from the National Football League (NFL), National College Athletic Association (NCAA) and the Olympics, but not from major league baseball.
While the FDA believes ephedra causes 64 per cent of all reported side effects from herbs, and only makes up less than 1 per cent of herbal supplement sales, the Ephedra Education Council (EEC) insists that the herb is safe when used as directed. This week the industry body issued a statement to the FDA arguing against an outright ban on ephedra products.
EEC said that a national standard on a warning label for ephedra products is supported by the current science on ephedra, but a ban based on an arbitrary and undefined standard of 'significant or unreasonable risk' is not. The statement was in response to the reopening of the comment period on pending ephedra regulations.
"A strong, comprehensive warning is needed, but the required warning should provide consumers with accurate information to facilitate informed choices, rather than blatantly mislead them - as does the currently proposed warning," continued the statement.
The study will be presented at the Experimental Biology 2003 meeting, being held April 11-15, 2003, at the San Diego Convention Center, San Diego, CA. It is expected to attract more than 7500 scientists and researchers.