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Hoodia gordonii has been sold as a dietary supplement in the United States for approximately three years; and, it is now used in more than 100 branded dietary supplement or food products, alone or in combination with other natural substances for weight control. Information supplied by some manufacturers and purveyors of Hoodia supplements may not be entirely accurate, a problem apparent on many Web sites that sell Hoodia supplements.
There are several current controversies surrounding Hoodia. Hoodia’s U.S. regulatory status and its long-term viability as an endangered species. In addition, issues were discussed about limited health claims that can apply to Hoodia supplements, in order that the marketing of Hoodia-containing supplements may conform to regulatory guidelines. This month, we look at controversies that surround the potential bioactivity or authenticity of some Hoodia supplements.
Issues concerning the source, purity, biological contents and integrity of bulk Hoodia powder sold to manufacturers of dietary supplements, especially encapsulated supplements, remain the focus of intense arguments among different commercial operations.
The continuing willingness of some purveyors of dietary supplements to make stand-alone treatment claims for obesity has attracted regulatory intervention. Obesity is defined as a disease, and it is not amenable to any single intervention. While the pharmaceutical industry has been quick, on occasion, to criticize supplement claims, they have had their own regulatory problems with weight loss claims and anti-obesity drug safety.
The Dietary Supplement and Health Education Act of 1994 (DSHEA) permits the use of third party literature to sell a dietary supplement product, providing there is good scientific agreement contained within such literature, and providing such literature is geographically separated from the point of sale of the dietary supplement. There have been several articles and books written on the subject of Hoodia, but these publications have not been used as product labels.
I have discussed some problems with the transition of the sale of dietary supplements from “bricks and mortar” retail locations to the Web. In a standard retail location, dietary supplement consumers have the advantage of a consultation with informed sales staff, and there is ability to separate third party literature from the point of sale of the supplement. These circumstances do not present themselves to Internet purchasers of dietary supplements, and there is no clear legal precedent describing geographic separation of third party literature from the point of supplement sales in electronic formats, such as the Internet. In other words, how does one readily separate necessary consumer information from the point of sale of supplements on the Internet?
It is common knowledge that weight control is a function of several factors, including diet, behavior modification, exercise and adjunctive weight loss aids, in some circumstances. Species of Hoodia, most notably Hoodia gordonii, like all other supplements used for weight control, can only be considered to have an adjunctive role in weight loss. The reported ability of Hoodia species to induce appetite suppression in some people, without cardiovascular stimulation, may meet the important objective of calorie control in the diet for weight loss. Pundits claim Hoodia may fill the void created by the removal of ephedra (Ma huang) from the supplement market. This remains to be seen, and I caution readers that not all people who take Hoodia supplements can expect to experience appetite suppression. In fact, the effectiveness of Hoodia supplements in weight control has not been studied in any detail. In particular, there is insufficient research to support a general claim for efficacy of many Hoodia supplements.
Phytopharm PLC (Oxford, England) licensed a patent owned by the CSIR (a government agency in South Africa) on the use of steroidal glycosides and related chemical compounds for weight loss. Steroidal glycosides are molecules found in Hoodia species, especially Hoodia gordonii, with demonstrable effects on feeding behavior in animals and appetite regulation in very limited human studies. The author stresses that the appetite suppressing properties of Hoodia species are best described as an ethnocentric discovery of the San bushmen in the folklore use of Hoodia over a period of many years. The CSIR patent has been sublicensed to Fortune 500 companies in the pharmaceutical and food industry, and steroidal glycosides are stated to be the active components of Hoodia that suppress appetite. The principal patent on the active constituents of Hoodia species, filed by the CSIR, is commonly referred to as the “Phytopharm patent”. This patent licensed by Phytopharm PLC does not cover the use of whole Hoodia as a health food or dietary supplement; however, patents have been filed in the dietary supplement industry for the use of Hoodia in combination with other natural substances for weight control.
Prevailing thoughts in the supplement industry imply that Hoodia gordonii may be most effective as a dietary supplement when used as whole dried aerial plant, in an initial dosage of a least 800 mg/d, followed by a maintenance dosage of 400 mg/d, monitored for continuing benefit. Despite the emerging evidence for these dosage requirements, the best-selling forms of Hoodia in mass markets contain only small amounts of Hoodia in combination with other putative weight control ingredients.
Retail health food stores that provide value-added educational services to consumers can take the initiative to discuss these important matters with their clients. However, there are no clear dose/response studies available to give clear guidance on the optimal dose of whole dried Hoodia plants for their potential, adjunctive role in weight control.
Analyzing Hoodia Supplements
There are several ways of analyzing Hoodia gordonii to determine its suitability for use in a dietary supplement (www.Hoodiatesting.com). Analytic techniques applied to bulk Hoodia power used in supplements include non-specific analysis of nutritional contents, microscopic examination, spectroscopic analysis and specific chemical analysis of marker compounds, including steroidal glycoside molecules. The laboratory methods used to check the purity, quality and consistency of Hoodia gordonii have been the subject of debate and some major differences of opinion, especially in the area of chemical analysis to identify the presence or absence of steroidal glycosides.
Laboratory studies aside, clinical outcome is the most important aspect in the measure of the effectiveness of any drug or dietary supplement. In an open-labeled, observational study, 400 mg of Hoodia bulk powder, tested in the laboratory for its authenticity, was given twice daily in a vegetable capsule to eight obese individuals.
Sequential measurements of weight revealed an average weight loss of nine pounds, over a four-week period, in these subjects. All individuals in this study reported a reduction in appetite and a fall in dietary calorie intake, estimated by dietary recall to be a reduction of about 500 to 1,000 calories per day. Another, observational study in seven patients produced similar results with a Hoodia supplement.
Retailers of Hoodia should satisfy themselves that the products they sell labeled as Hoodia gordonii have correct certification and a complete laboratory analysis of contents (including spectroscopic and HPLC and clinical outcome studies). Anything less than these criteria cannot permit a conclusion that a given Hoodia product is authentic.
I believe Hoodia gordonii is one of the most important ethnobotanical discoveries of the 20th century. If its appetite-suppressant properties are confirmed in further clinical study, this plant will be one of the most powerful tools to help combat the global pandemic of obesity.
Source: By Stephen Holt, from hsrmagazine.com |
