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The South African desert
plant Hoodia gordonii, long ingested by Kalahari bushmen, has
begun to attract widespread attention as a weight loss aid.
The only place in the world where Hoodia grows in the wild
is the Kalahari desert in southern Africa. The plant has been
eaten for centuries by the Kalahari bushmen living in the area,
reportedly to prevent hunger during long journeys. A South
African laboratory that had been studying indigenous plants
for many years identified a molecule in the Hoodia plant, termed
P57, that appears to suppress appetite. The South African researchers
applied for a patent for the use of this compound as a diet
aid and licensed it to a British pharmaceutical company, Phytopharm.
Scientists from Phytopharm say that the active ingredient
in Hoodia, P57, acts on the brain in a manner similar to glucose
and sends the message that you are full even when you have
not eaten, thus decreasing your desire to eat. Ingestion of
the Hoodia plant has no known reported side effects, although
its taste is considered to be unpleasant and bitter.
According to CBS and BBC news reports, Phytopharm has spent
millions of dollars in research on Hoodia and conducted a study
of its effects on human volunteers. In their study, they report
that obese volunteers who took Hoodia ended up eating about
1,000 calories per day less than those who did not take the
supplement. But the pharmaceutical firm Phizer, which had teamed
with Phytopharm and funded much of the research on Hoodia,
dropped out of the project because of beliefs that it wouldn’t
be realistic to make pills out of the active ingredient in
the Hoodia plant. Hoodia is grows in extremely hot conditions,
and the plant takes years to reach maturity. Until now, the
plant has never been cultivated and was only found in the wild.
In order to increase its very limited supply, Phytopharm has
established Hoodia plantations in South Africa, which are trying
to establish cultivation and farming methods to grow the wild
plant.
The BBC also reported in 2003 that it tested the “leading
brand of Hoodia pills” sold in the U.S. and found no
discernible evidence that the pills contained any active Hoodia.
Because of the relative scarcity of Hoodia, the ingredient
is hard for manufacturers to acquire, which makes it hard to
understand how dozens of firms now claim to sell weight loss
supplements containing Hoodia. Scientists at Phytopharm claim
that many firms are fraudulently using their data and claims
about Hoodia to market their own products. Phytopharm states
that assays of “Hoodia” supplements from different
companies show that these contain between 0.1 and 0.01 percent
of the active ingredient claimed, according to a CBS report
in 2004.
The study cited by the manufacturers of Hoodia certainly sounds
intriguing. However, the study has not appeared in a peer-reviewed
medical journal, so it is impossible to evaluate the quality
of the study or its methodology. The FDA has warned manufacturers
of products claiming to contain Hoodia that its effectiveness
and safety have not been determined in humans. Likewise, both
the Mayo Clinic and Dr. Andrew Weil have commented that there
is of yet no conclusive evidence that Hoodia is a safe and
effective appetite suppressant.
Right now, it’s just too early to tell if Hoodia will
revolutionize the diet industry. Double-blinded clinical trials
are required to establish the safety and effectiveness of any
product, and these have not yet been completed with Hoodia.
Even those interested in trying Hoodia without waiting for
clinical trials to be completed may have difficulties, since
Phytopharm, the only licensed producer of Hoodia as a weight
loss aid, does not yet market the product. Phytopharm’s
Web site states that “the necessary clinical trials and
other studies to ensure the safety of the extract will take
a few years before a product will be available.” With
reports of widespread counterfeit product, unless you have
your supplements tested by an independent laboratory, it’s
hard to know if you are actually purchasing a product that
truly contains the active ingredient. |
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