Green Coffee beans - the new weight loss formula

By Dr. Ananya Mandal, MDMar 29 2012

Green coffee beans could be the newest weight-loss fad as a new study finds that the bean extract may help people lose weight. When roasted at 475 degrees, coffee beans are sometimes described as rich and full-bodied. Before that they are termed green.

The bean, which is sold as a supplement in the U.S., has been deemed an effective weight-loss food by author Joe Vinson who is a chemist at the University of Scranton in Pennsylvania. He said, “Taking multiple capsules of green coffee extract a day, while eating a low fat, healthful diet and exercising regularly, appears to be a safe, effective, inexpensive way to lose weight.”

Mr. Vinson and a team of researchers gave 1,050 milligrams of green coffee bean extract to 16 obese adults in their twenties. They kept a close eye on the participant's diets, heart rates, exercise regimes, weight and blood pressure over 22 weeks.

The study used a “cross-over” design, which allowed each subject to serve as his or her own comparison group. For six weeks, volunteers swallowed capsules three times a day, ingesting either 700 or 1,050 milligrams of green coffee extract a day or taking a placebo. After a two-week break, they moved, round-robin style, to another arm of the trial. Subjects did not change their calorie intake over the course of the trial. But the more extract they consumed, the more weight and fat they lost.

Altogether, they reduced their body fat by 16%, on average. Of the 16 volunteers, six wound up with a body mass index in the healthful range. Each of the volunteers shed an average of 17 pounds each. It worked out to be about 10.5 per cent of the group’s overall body weight.

Although the author admitted he is not certain as to why the particular bean works, he thinks the chlorogenic acid found in green coffee beans may play a key part. One downside is that the extract is “extremely bitter.” It would be difficult to take without a lot of water, Vinson reported. At roughly $20 per month, however, green coffee extract is much less expensive than any of the weight-loss medications available over the counter or by prescription. Experts have warned not to be over-excited about the results till they are proven further.

Dr David Katz, a director of Yale University’s Prevention Research Center in New Haven, Connecticut, said it is too early to be recommending the green coffee beans to people looking to lose weight. “The effects, if real, are likely to be modest and we don’t know if they last over time,” he said. “It’s a supplement, not a substitute. The emphasis will always need to be on overall diet and physical activity.”

Keith Ayoob, a dietician and associate professor at the Albert Einstein College of Medicine in New York said, “I’d be happier if the research included pure caffeine, in the same amount as is contained in the doses of [green coffee bean extract],” he said. “Then you’d know if the effects are due solely to caffeine or to something else in the beans, or to some combination thereof.”

“This is certainly a provocative study,” said Dr. Gerald Weissmann, a physician and biochemist at New York University. But he said nutrition experts would want assurances that green coffee beans do not cause “malabsorption” within the human gut — a condition that would lead to weight loss as well as malnutrition, heart arrhythmias and other problems because vitamins and minerals are not passing through the intestine.

Dr. Arthur Grollman, a pharmacologist at the State University of New York at Stony Brook, said coffee beans contain about 250 different chemicals - some with positive and others with negative effects on human health. Though Vinson identified polyphenols and chlorogenic acid as the agents that appear to promote weight loss, Grollman said that claim needed further study. In the meantime, he said, consuming an extract that contains both good and bad chemicals in dense concentration seems an unwise thing to do.

The study was conducted in India and funded by Applied Food Sciences of Austin, Tex., which makes the green coffee antioxidant supplement. The study was presented Tuesday at the American Chemical Society's spring national meeting in San Diego.