Green Coffee Bean Extract–Magical Weight Loss Supplement: Fact or Fiction?
Joseph Flanagan MD, FACEP, FACEP
By now, everyone has heard all the hype about green coffee bean extract and its ability to cause weight loss. It seems like we have been bombarded with this news on the internet and television. The questions is: Does it really work? The answer, it seems, is yet to be determined. The most recent study involved only 16 adults between the ages of 22 and 46. They were given a standard coffee bean extract of chlorogenic acid and other organic acids at varying doses of between 700-1050 mg per day for 12 weeks. These over-weight adults (BMI greater than 25 with normal being between 18.5 and 25) lost an average of 18 lbs or 10 % of their over-all body weight, with no dieting or increase in exercise. There were no reported adverse side effects. The researcher did not believe caffeine was the cause of the weight loss.
Previous studies have suggested that chlorogenic acid is the key chemical causing this weight loss. It has been shown to decrease liver glucose (sugar) and slow the absorption of fat from foods while increasing the metabolism of fat. The roasting of coffee beans for brewing is done to remove its bitterness. The roasting also removes most of its chlorogenic acid.
The results of this small study are promising, but it will take a much larger study of longer duration to sort out long term effects and safety. Additionally, given the limited age range of the test subjects, efficacy, and safety for older adults is not known.
Not all green coffee bean extracts are created equal. Make sure to search for a product that lists its ingredients. Look for a product that has 45% or more of chlorogenic acid at doses of 200-400mg. Take it no more than three times per day, 30 minutes before meals. Do not take it if you are allergic to caffeine or coffee.
If you decide to try it, understand that supplements are not held to the same scrutiny as pharmaceutical medications and there have been many problems caused by supplements in the past. Also, be aware that because it has not been adequately studied, there is risk of unknown adverse side effects.