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Guarana & Caffeine Research

Jul 6, 2011 | By Michelle Matte
Guarana & Caffeine Research
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Caffeine is a stimulant found naturally in many foods, particularly coffee, tea, kola and chocolate. Many products, particularly energy drinks, add caffeine in the form of guarana, extracted from berries that grow on a bushy plant native to the Amazon basin. The use of guarana and caffeine as weight-loss aids, as performance-enhancing supplements in sports and as mental stimulants have sparked research into the mechanisms by which caffeine affects human performance.

Guarana and Caffeine

Guarana is often promoted as a more natural stimulant than caffeine, less likely to cause jitters or digestive discomfort. But student researchers at the University of Massachusetts found the chemical structure of guaranine, the stimulant found in guarana, to be identical to caffeine. The caffeine in guarana, however, appears to be more concentrated than that in coffee. According to William J. Keller, PhD, professor at the Northeast Louisiana University School of Pharmacy in Monroe, a beverage made from guarana has three times more caffeine than a cup of coffee of the same size.

Caffeine and Weight Loss

Caffeine has been embraced by many as a weight-loss aid because of its ability to mobilize fatty acids in the bloodstream during exercise, making fat more available for energy production while sparing muscle glycogen. In a small 2010 study, student researchers at the University of Massachusetts compared the effects of guarana and caffeine on fat oxidation at rest and found the effects of both substances to be similar. However, it is unclear whether consuming caffeine in any form in the absence of exercise enhances weight loss.

Caffeine and Athletic Performance

According to Dr. Mark Tarnopolsky of McMaster University in Canada, clinical evidence of the positive effect of caffeine on athletic performance abounds. Tarnopolsky and others report that caffeine facilitates the release of calcium in muscles, which enhances power output, improving performance in laboratory settings by 20 to 25 percent. Louise M. Burke, head of sports nutrition at the Australian Institute of Sport in Canberra notes that athletic performance can improve in doses as small as 1 mg per kg of body weight, the equivalent of 4 oz. of coffee for a 175-lb. athlete.

Caffeine and Mental Performance

Caffeine has long been relied upon to fend off grogginess and enhance mental focus. It does so by interfering with adenosine, a chemical that acts as a natural sleeping pill. Hungarian mathematician Paul Erdos, known for working equations tirelessly around the clock, is quoted as saying that "a mathematician is a machine for turning coffee into theorems." A 2005 study presented at the annual meeting of the Radiological Society of North America scanned brain activity of subjects taking a memory test after being dosed with caffeine, and found that caffeine increased activation of the part of the brain responsible for memory.

References

Article reviewed by MER Last updated on: Jul 6, 2011

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