Watch CBS News

HealthWatch: Health Questions Raised About Green Coffee Bean Extract

SAN FRANCICO (CBS 5) - Internet and television advertisements are touting Green Coffee Bean Extract as a weight loss aid, but some medical professionals aren't sure we know enough yet about the diet supplements.

A few months ago, Roberta Lew went on Facebook, and saw an ad about a miraculous fat-buster called Green Coffee Bean Extract.

It seemed simple enough, and Dr. Oz on his national show was quoted as touting the new dietary supplement.

"If you can take two pills a day, you're in," Lew explained.

Online, she found varieties of the supplement for sale, and thought she'd give it a try.

"So I clicked on it. I ordered it," said Lew.

She started taking a capsule a half hour before a meal, with a big glass of water.

Without changing her diet or adding exercise, she said she was stunned.

"It's great. I lost my belly fat and ten pounds in two months without even trying," said Lew.

Green coffee extract comes from unroasted or green coffee beans. What's in the beans?

Caffeine is a well known stimulant. But they also contain chlorogenic acids which is a substance that's believed to help your body better metabolize fats and carbohydrates.

In a small study, sixteen subjects lost more than 10% of their body weight in just five months, but some experts are voicing strong concerns.

"I worry that we don't even know the right dose to take of chlorogenic acid or green coffee extract," said Dr. Marc Hellerstein, is a nutritional scientist at U.C. Berkeley,

Hellerstein studies nutritional metabolism, and is also a Medical Doctor who specializes in endocrinology and diabetes. Dr. Hellerstein said that the study on humans is too small to draw any conclusion, and warns of both short and long-term consequences.

"If people want to take it now, I'd be careful. We don't know about toxicities," said Dr. Hellerstein.

A new study suggests we don't know what's even in these supplements.

Consumer Labs tested many popular brands of green coffee extract and found 50% don't contain the expected amounts of ingredients for weight management.

The FDA recently issued a warning on how another brand actually contains a prescription appetite suppressant.

"Many products have been abused," said Dr. William Stewart.

Dr. Stewart runs California Pacific Medical Center's Institute for Health and Healing, where complimentary treatments are valued. But he too has too many questions about the extract.

"I'd be much more comfortable recommending it to people when I see further data," said Dr. Stewart.

As for Roberta Lew, she said she's experienced no side effects while taking this supplement.

"I'm on my third month and I plan on sticking with it," she said.

(Copyright 2012 by CBS San Francisco. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

View CBS News In
CBS News App Open
Chrome Safari Continue
Be the first to know
Get browser notifications for breaking news, live events, and exclusive reporting.