To Your Health
What is the evidence that hoodia works as an appetite-suppressant?
A. Hoodia (in particular the species Hoodia gordonii) is a cactuslike succulent plant that grows in the African Kalahari desert. The San people of the Kalahari, formerly known as Bushmen, traditionally ate hoodia to keep from getting hungry on long hunting expeditions. In 1996 the Council for Scientific and Industrial Research in South Africa was testing the local foods that the Bushmen ate and found that when they fed hoodia to animals, the animals lost weight apparently by suppressed appetite. Of course it did not take long before they realized this plant could be a gold mine. At present it appears that only one species of hoodia has appetite-suppressing qualities, and then only if it is grown in the Kalahari.
A company known as Phytopharm ended up with the patent on using hoodia for weight loss. Phytopharm is now in the process of developing hoodia farms in the Kalahari in anticipation of a large future market for it. Unilever plans to use hoodia in Slim-Fast, its weight loss meal-replacement drink, beginning in 2008. Obviously, however, hoodia is available in pill form right now. You can buy hoodia from companies that have no affiliation with Phytopharm as long as they do not state they are selling the hoodia as an aid to weight loss. The problem seems to be, is it really hoodia?
There are more than 20 species of hoodia plants, but only the Hoodia gordonii species has been shown to suppress appetite. In addition, only Hoodia gordonii grown in the Kalihari desert is known to contain the active ingredient, known as P57, which suppresses appetite. Furthermore, only the inner core of the hoodia plant has the P57, with very little in the skin and roots. A search of the Internet brings up dozens of Web sites of the rival companies that sell hoodia, each bitterly attacking and counterattacking the others regarding the quality of the hoodia they market.
This hostility probably stems from a lack of solid research on hoodia. There appears to be only one article on hoodia in the peer-reviewed scientific literature (Brain Research, Sept. 10, 2004, pp.1-11), and when information is not available, speculation takes over. This article demonstrates that P57 injected directly into the brains of laboratory animals reduced their food intake by 40-60% over the following 24 hours. This experiment has obvious limitations, since this is not the way we ordinarily take substances into our bodies.
Other animal experiments and clinical trials that have been published less formally indicate that hoodia is nontoxic and performs "as advertised." Future research should verify that P57 affects the hypothalamus of the brain, mimicking the effect of a rise in blood sugar. The rise in blood sugar after a meal is only one of several body signals that the hypothalamus monitors in order to control appetite, but it is the one that is more likely to trigger a between-meal "snack attack."
If we can now develop a pill that increases our will to exercise, we may yet overcome the current trend toward increasing obesity in America.