Hoodia - a pirate's nightmare?

From reports in the late 1990s suggesting that the hoodia gordonii plant could suppress appetite, to the media explosion following coverage on the US TV show 60 Minutes​ in 2004, hoodia has become the most infamous weight management ingredient in town.

Ever since the South African Council for Scientific and Industrial Research licensed hoodia's active ingredient P57 to UK-based pharmaceutical development and functional food firm Phytopharm in 1997, the hoodia market has gone into overdrive, with pirated and generic copycat products sold across the globe.

Beyond the patent infringements currently evident against Phytopharm, many, if not all, generic or copycat products do not actually contain P57. At present the Convention on International Trade in Endangered Species (CITES) issues certificates guaranteeing as authentic hoodia from South Africa; but this does not guarantee that P57 is actually in the end products.

Copycat products damage not only the hoodia market but also consumer confidence in the wider dietary supplements industry.

In recent weeks, US analytical firm Chromadex has attempted to address this by providing a phytochemical reference standard that can be used to identify the authenticity and content of the P57 active. Following an independent review by American Herbal Pharmacopeia, this standard will help manufacturers provide a seal of assurance regarding the presence and quantity of P57.

Promises versus delivery

So what has Phytopharm been up to, in order to deliver on these early promises of a miracle weight loss product? At present its licence rests in the hands of Unilever following a £21M deal in 2004 and a royalty agreement for hoodia use in Unilever's Slimfast brand.

In a recent statement, Phytopharm revealed that phase one of a five-phase clinical research programme had been completed and that phase two was underway.

But when will details of this research actually surface? In 2001, Unilever claimed that human trials had revealed hoodia's ability to curb appetite and facilitate weight loss. In what many suggested was a shrewd move to stop competitors from using its data to boost product sales, however, the results were never published in a peer reviewed journal.

Proof at last?

However, in a recently published paper in the journal Phytochemistry, Phytopharm has given us a clearer taste of hoodia's potential for weight management - albeit in rats.

Researchers from the University of KwaZulu-Natal, South Africa, identified and extracted the biologically active compounds from Phytopharm's source of hoodia. The most interesting part of their research was the appetite-suppressant activity and dose responses of the trisaccharide glycoside previously identified as P57AS3 or P57.2.

The results showed that after three days of supplementation the hoodia extract significantly reduced food consumption in female rats. The authors also say that bodyweight was reduced. However, I would like to see the raw data since the mean change was relatively small given the large variation within the groups.

Interestingly, the hoodia extract was also compared to the known appetite suppressant fenfluramine, although not using an equivalent dose. While the data showed a decrease in appetite in both groups, only the hoodia P57 group demonstrated a corresponding decrease in bodyweight as well.

Furthermore, after three days of supplementation, bodyweight and appetite were measured until day eight. The data showed continued appetite suppression in the P57 supplemented rats until day eight but not in the fenfluramine group. As for dosage, an effect on appetite from P57 could be observed from 6.25mg/kg/day to around 37mg/kg/day, but no greater effect was evident at a higher dose.

This very interesting data is likely to reignite the hoodia storm for the generic suppliers until the new Chromadex standards are up and running.

However, even with the progression of these trials on Phytopharm's hoodia extract, issues relating to the European Novel Food Regulation are still a concern and recent rumblings from Unilever suggest we will not see hoodia/Slimfast products on the shelf before 2010.

Dr Mark Tallon is a consultant and co-founder of dietary supplements firm CR-Technologies. Contact him at: bkltravk2004@nby.pbz​​