When TV's "Dr. Oz" calls something a "revolutionary fat buster," the world pays attention. That's what he did recently in touting a dietary supplement called garcinia cambogia, which his website says "can help you double and triple your weight loss."
Two Long Island nutritionists, though, said they aren't ready to join the rush to embrace garcinia cambogia.
They urge caution about the supplement, pointing to studies that have shown limited results and signs of potential harmful effects.
"I tell my patients that, although this supplement may help them lose a few extra pounds, it is not going to help much," said Josephine Connolly Schoonen, executive director of Stony Brook Medicine's nutrition division and an associate clinical professor of family medicine at Stony Brook University.
Heart surgeon Mehmet Oz is a popular TV personality with a devoted following. But Oz, who may be the nation's most famous doctor, is also controversial. Critics have accused him of promoting unproven and potentially dangerous health fads.
One thing is clear: Oz can draw major attention to obscure medical products. Garcinia cambogia supplements, derived from a plant, have developed a higher profile in recent months after Oz promoted them. Extract from the small, yellow garcinia cambogia fruit, also called tamarind, is used to make the supplements.
Tim Sullivan, a spokesman for Oz and his television show, said " . . . there is an urgent need for new research to determine the overall health effects of all products . . . . As with all supplements discussed on 'The Dr. Oz Show,' any decision about what to take and for how long should be done in conjunction with one's primary care physician."
Studies are mixed
Connolly Schoonen said that a few of her patients have asked about the supplement, and some started taking it before asking her for advice. It's available online and at health food stores and pharmacies.
Research into the supplement is limited, she said, and study results have been mixed. "It does not appear to have a consistent effect on decreasing appetite or a very strong impact on weight loss," Connolly Schoonen said. However, she noted that one study suggests that people on a very strict low-calorie diet (1,200 calories a day) may lose two to three extra pounds if they take the supplement.
Another study, she said, suggests more weight loss among people who take a supplement with garcinia cambogia among its ingredients. "However, these differences are quite small and may not last more than a few months," Connolly Schoonen said.
Other research hints at possible trouble for people who take the supplement. A South Korean study published in August reported that mice that were given the supplement developed liver scarring and inflammation.
As for other side effects, Connolly Schoonen said, "There has been a reported case of the development of an unusual skeletal-muscle condition, called rhabdomyolysis, associated with a supplement containing garcinia cambogia, among other ingredients."
In addition, people with diabetes who take the supplement "should work with their physicians to monitor their blood work, as there may be combined effects with medications used to treat this condition, leading to hypoglycemia, or low blood sugar," she said. And she suggested that people with Alzheimer's disease avoid garcinia cambogia because of the possibility that it could affect the illness.
Don't look to the FDA
As with all dietary supplements, garcinia cambogia does not require U.S. Food and Drug Administration approval to be sold. Supplements are not inspected for safety or quality, although the U.S. government can take action if an unsafe product has reached the market.
Marina Stauffer Bedrossian, a clinical dietitian at St. Catherine of Siena Medical Center in Smithtown, urged people curious about garcinia cambogia to consult a doctor or registered dietitian before trying the supplement. In general, she doesn't recommend any weight-loss supplements "because there is no easy way to lose weight," she said.
"Most weight-loss supplements are advised to be used along with diet and exercise or only when those two fail," Stauffer Bedrossian said. "However, I have not seen a case yet where diet and exercise did not work to help a patient lose weight, body fat mass or both."
If someone insists on taking garcinia cambogia, Connolly Schoonen said, "I ask them to work on following a healthy eating style without the supplement at first so they do not confuse the impact of the healthy diet with that of the supplement."
Then, she said, "After doing so, if they really want to determine if the garcinia cambogia can help further, they should make sure their physician is aware and can help monitor lab work or assess any unusual symptoms."