Do they trim your body or just your wallet?
By Kelly A. Goff
As the rates of obesity skyrocket, Americans continue their search for a quick, easy answer to weight loss. Many look to weight-loss supplements and hope for a “magic pill” effect. Promises like appetite suppression, metabolism booster and carbohydrate blocker sound effective, but do they work as purported?
A review of some of the most popular ingredients in weight-loss supplements mostly reinforces what many of us know intellectually is true, but hope emotionally is not true.
Carbohydrate blockers
Phaseolus vulgaris – The water extract of a common white kidney bean, it is touted as inhibiting amylase, an enzyme that breaks down starch in the gut. There is one preliminary study with 27 participants that showed after eight weeks the bean extract group that took 1,500 mg twice daily with meals lost about two pounds more over two months than those who took the placebo. None of the participants experienced any serious side effects from the medication. However, researchers believe further studies with more people are needed to demonstrate conclusive effectiveness.
Chromium picolinate – Chromium is thought to play a role in carbohydrate and fat metabolism, potentially influencing weight and body composition. Most weight-loss supplements use chromium picolinate in daily dosages of 200 to 400 mcg. There is evidence showing ingestion of more than 1,000 mcg daily can cause free radical damage and kidney failure. Because of the lack of large, well-designed studies, it remains unproven whether chromium works for weight loss and if it’s safe to use long-term.
Ginseng – While there is evidence that shows ginseng may affect blood sugar, it has not been shown to affect weight loss.
Appetite suppressant
Hoodia gordonii — Made from a succulent that grows in South Africa and Namibia, hoodia is said to be an appetite suppressant that indigenous tribes use to make long treks through the Kalahari Desert with little food.
Does it work? There is no evidence to say. Interestingly, the pharmaceutical giant Pfizer bought the clinical development rights to hoodia from a British company in 1998 but returned them in 2003. In addition, the cactus is so rare that some experts question whether there’s enough to actually supply all the products said to contain it.
How do you know whether the product you’re buying contains hoodia, much less in the amount advertised? You don’t. “There are no established scientific standards to measure the quality of hoodia products,” says physician Tod Cooperman, president of ConsumerLab.com, which tests dietary supplements and other products.
Satiety supplements
Theoretically, if you feel full and satisfied, you won’t eat as much and will lower your caloric intake. It’s a good theory, except many Americans simply override their body’s signals. Supplements glucomannan, psyllium and guar gum are often used in weight-loss products to produce a feeling of fullness.
Guar gum is often used in processed foods as a thickening agent. Although it is relatively safe, studies of guar gum versus placebo for weight loss showed no benefit. A couple of small studies suggest that glucomannan in dosages of 3 to 4 g per day may be well tolerated and yield modest weight loss. Psyllium had a positive affect on blood sugar levels of Type 2 diabetics, but did not result in weight loss.
Stimulants
Also advertised as metabolism boosters or thermogenic formulas, stimulants such as caffeine (typically in the form of guaraná, kola or yerba maté) or ephedrine (in the form of the herb ephedra), come with the risk of addiction. Harvard-trained medical doctor and integrative medicine guru Andrew Weil, M.D., says to stay away from these compounds. “The term ‘thermogenics’ refers to an increased production of heat in the body, yet the safest and most effective way to generate more heat and boost your metabolism is not through a supplement or drug, but with regular physical activity,” he says.
Some popular stimulants include:
Ephedra – Also known as ma huang and ephedrine, it comes from a shrub native to China and Mongolia. Although ephedra-caffeine combinations may be effective for modest weight loss, the FDA banned their sales in April 2004, citing “an unreasonable risk of illness or injury.” In addition to the risk of addiction, ephedra can cause irregular heartbeat, insomnia and high blood pressure. A recent article about common dietary supplements in American Family Physician, a peer-reviewed journal, reported serious side effects such as heart attack, stroke and seizures; 10 deaths have been linked to the medication, and 13 people have permanent disability. The researchers who wrote the article titled Common Dietary Supplements for Weight Loss, also noted nine out of these 23 reported episodes occurred at recommended dosages of ephedra in people without any heart-related health issues.
Bitter orange — The main active ingredient is synephrine, a stimulant similar in action to ephedrine. Researchers caution that bitter orange may be dangerous, especially when used by the elderly, the obese and those with heart problems.
Fat burners
Garcinia cambogia — Derived from the Malabar tamarind tropical fruit, the active ingredient here is hydroxycitric acid (HCA). Some data from animal studies suggest it may suppress appetite as well as the formation of fats and cholesterol in the liver, but there’s no evidence that it’s effective for weight loss in humans.
Pyruvate — This naturally occurring enzyme is the main ingredient in the weight-loss product “Exercise in a Bottle.” Promoters claim that pyruvate forces every cell in the body to work harder whether or not you’re exercising. The Federal Trade Commission has filed multiple complaints against the makers of “Exercise in a Bottle” for false claims made on a now-banned television infomercial. However, one study reported six weeks of pyruvate, in a dosage of 6 g per day, was associated with a weight loss of a little more than two pounds when compared with the placebo group.
Green tea — Although it’s bursting with healthy antioxidants, there is no research to support that it decreases weight.
Fat blocker
Chitosan – This compound is extracted from crustaceans. According to Robert Saper, director of integrative medicine at Boston University School of Medicine, chitosan causes minute, clinically insignificant weight loss. “For chitosan to truly cause weight loss, you would have to eat several pounds of it per day, not 500 mg!” he said during a recent WashingtonPost.com-question-and-answer forum. Some who have taken chitosan have also reported gastrointestinal problems.
Are weight loss supplements safe?
“Most people aren’t really aware that the dietary supplement bottle on the shelf is not regulated the same way as other products next to it,” says Dr. Saper. Unlike medicines, the government only loosely regulates weight-loss supplements. When Congress enacted the Dietary Supplements Health and Education Act (DSHEA) in 1994, it gave dietary supplements a pass on undergoing this kind of pre-market scrutiny.
What worries some experts more than safety and effectiveness is the purity of weight-loss products. The lack of oversight and regulation means it’s up to consumers to protect themselves. Dr. Saper wonders about trace contaminants, such as heavy metals, pesticides or residues of other pharmaceuticals. “If a product says that it contains 200 micrograms of chromium picolinate, are there indeed 200 micrograms in that capsule?” he asks.
When ConsumerLab recently tested a supplement that contains chromium, it reported that it found traces of hexavalent chromium, the same compound that led to a $333 million settlement made famous in the Julia Roberts movie Erin Brockovich.
Despite the risks, some consumers are determined to use weight-loss supplements. “Stick with single-ingredient products. Often marketers will say that you will get some great synergy by mixing ingredients, but it’s a safer bet to go with a single-ingredient product to see if it works,” advises Cooperman of ConsumerLab. “And stay away from products that have proprietary blends. That’s where you don’t know what the exact ingredients are.”
The bitter pill
Although the research on some supplements sounds hopeful, ultimately we’re forced back to reality. Common sense dictates that if there were a weight-loss supplement that really worked, McDonald’s would have started including it in Happy Meals long ago. only formula for weight loss that works is eating less and exercising more, and that won’t cost you anything,” says Dr. Weil.
Consumer, educate thyself
Varro Tyler, PhD, professor emeritus of pharmacognosy at Purdue University, West Lafayette, Ind., and an herbal expert, urges consumers to get information from someone who is not selling the product and to trust authors who do not have an herb company. He recommends two books, Tyler’s Honest Herbal, by Tyler and Steven Foster and Herbal Medicine: Expanded Commission E Monographs, edited by Mark Blumenthal, founder of the American Botanical Council.
For online research, try the following:
The Federal Trade Commission’s “Red Flag Reference Guide for Bogus Weight Loss Claim Detection,”
www.ftc.gov/bcp/conline/pubs/buspubs/redflag
or try one of these useful Web sites:
www.naturalmedicines.com
www.consumerlab.com
www.naturalstandard.com
www.intelihealth.com
www.nccam.nih.gov
