Guarana extract is derived from the seeds of a fruit-bearing vine found in Brazil. It is among the preferred sources of caffeine used in weight-loss aids, but it used for many other purposes as well. Caffeine is a stimulant to the central nervous system that can increase your metabolism rate and energy while suppressing your appetite. Be sure to look at labels if you take a diet aid, and stay within the recommended limits for caffeine intake. Both caffeine and guarana are found in some surprising places, like alcoholic beverages, medicine and meat.
What is Guarana Extract?
Guarana comes from an evergreen vine that is native to the Amazon basin. One cup of guarana is equivalent to about 50 mg of caffeine. Nutrition organizations recognize guarana for its thermogenic, or heat-producing, effect, which can increase metabolism. It is a common ingredient in over-the-counter weight loss aids that claim to increase your energy, reduce your appetite and boost your mental alertness. More than 500 products containing guarana are sold in the United States, according to the "Wall Street Journal."
Caffeine
Caffeine is a natural ingredient found in more than 60 plants, including coffee beans, kola nuts and guarana seeds. The American Society for Nutrition says about 90 percent of adults in the Western world regularly consume caffeinated beverages, making it among the most widely used stimulants in the world. Within 30 minutes of being consumed, caffeine crosses the blood-brain barrier and stimulates the release of epinephrine, otherwise known as adrenaline. It makes your heart beat faster, your breathing tubes flare, your blood pressure rise and your liver emit extra blood sugar.
Guarana, Caffeine and Weight Loss
Guarana seeds individually have more caffeine in them than coffee beans, making them an efficient way of releasing the stimulant through diet aids. Caffeine, including that found in guarana extract, works to increase alertness and suppress appetite. The International Food Information Council Foundation (IFIC) reports on a 1996 study that concluded caffeine also enhances physical performance. Researchers from Canada's University of Guelph found that by consuming about 6 mg of caffeine per kilogram of body weight, athletes experienced increases in muscular endurance during exercise. In non-athletes, lower doses produced similar results, and the greatest effect, says the IFIC, came when participants took caffeine one hour before physical activity.
Potential Dangers
People with heart conditions should not consume guarana, but even without a heart condition, taking a weight-loss aid and drinking coffee can cause heart-related problems, from an abnormally fast heartbeat to problems with heart valves. In the early 2000s, sellers of alcoholic beverages began adding guarana and other forms of caffeine to their drinks. This may have led to many thinking they were alert enough to drive. In 2010, Congress began considering legislation banning the practice. Analyses by the USDA in caffeine-containing products showed the actual caffeine content of many items was up to 16 percent more than what was on the label. According to "The New York Times," caffeine can cause hyperactivity and restlessness in children and increase their excretion of calcium.
Safe Limits
The American Society for Nutrition says no one should consume more than 400 mg of caffeine, or about two to three cups of coffee, daily. Guarana is generally recognized as safe by the FDA. Pregnant women should limit how much guarana and other caffeine they get because of the risk of harm to their babies. The FDA also allows a small amount of guarana to be added to meat for flavoring, but it is not enough to stimulate your central nervous system.
References
- UIC Medical Center: Alternative Medicine & OTC Weight Loss Pills
- American Society for Nutrition: The Role of Caffeine in Type 2 Diabetes
- Asian Food Information Centre: What You Should Know about Caffeine
- IFIC Review: Caffeine & Health: Clarifying the Controversies
- Wall Street Journal: Can a Caffeine-Packed Plant Give a Boost?
- Analytical and Bioanalytical Chemistry: The Caffeine Contents of Dietary Supplements Commonly Purchased in the US
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