Do they trim your body or just your wallet?
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
- 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
i
-- 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:
- 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.
-- 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.
-- 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.
-- Although it's bursting with healthy antioxidants, there is no research to support that it decreases weight.
Fat blocker
- 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.
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
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