A new Unilever report reveals why the consumer goods giant chose to pull the plug on the alleged fat-fighting supplement Hoodia after spending a reported R192 million developing it.
In a clinical trial, Hoodia extract had no impact on appetite or food intake, but it did have a lot of side effects, like vomiting, weird skin sensations and elevated blood pressure and heart rate.
Unilever has known this since 2008, but the news is bound to disappoint consumers, who can buy Hoodia for less than R153 on the Internet.
One website, for instance, claims Hoodia will curb your appetite almost immediately, after taking only a few milligrams, and will not make your heart race.
Too good to be true
Dr G. Harvey Anderson, a professor of nutrition at the University of Toronto, applauded the new report in an email to Reuters Health.
"This is a valuable study showing that the hype around Hoodia and its advertising in products claiming to contain it for weight loss belongs in the too good to be true category, said Dr Anderson, who was not involved in the Unilever study.
Things started out well for the herbal extract, which comes from the succulent plant Hoodia gordonii and has purportedly been used for millennia by Bushmen in the Kalahari trying to ward off hunger on long hunting trips.
Lab tests showed it made rats eat less and an unpublished study suggested the same was true for humans, according to the new report.
The plant's supposedly active ingredient was isolated by South Africa's Council for Scientific and Industrial Research (CSIR), which told Reuters in that Kalahari's Khomani people stood to get royalties from the Hoodia sales.
CSIR signed over the commercial drug rights to British biotechnology firm Phytopharm Plc in 1997. Phytopharm then struck a deal with the US-based drug maker Pfizer to develop a weight loss drug based on Hoodia, but that never panned out. So Unilever picked up.
But in 2008, the London- and Rotterdam-based company suddenly canned the project, telling Bloomberg News that Hoodia didn't meet safety and efficacy standards.
The report, published online in the American Journal of Clinical Nutrition, shows that's putting it politely.
Does not stifle hunger
In their trial, Unilever researchers randomly assigned 49 healthy, overweight women to one of two groups. Both groups stayed in a clinical research centre and were given two servings of yogurt a day for 15 days. In one group's yogurt drinks, the researchers had mixed in 1,110 milligrams of Hoodia.
The women were allowed to eat as much as they wanted during their stay at the clinic, yet there was no difference in kilojoule intake or weight loss between the two groups. Along the same lines, Hoodia didn't stifle anyone's hunger.
However, the Hoodia-treated women didn't fare as well as the placebo group. They experienced 208 cases of side effects – three times the number reported by women eating normal yogurt – including headaches, nausea, vomiting and odd skin sensations.
They showed increases in pulse and blood pressure, and signs of liver damage.
Failed diet pills
"There are many commercially available dietary supplements that claim to contain H. gordonii," Unilever's Wendy Blom and colleagues write in the report.
"Given the results here, we cannot exclude the possibility that consumers who take certain of these supplements could experience similar side effects."
The Hoodia-based medication no longer in development is just one example of a long series of failed diet pills. Earlier this year, for example, US health regulators rejected Orexigen Therapeutics' drug Contrave, which many had predicted would be the first new diet pill in a decade.
Unilever did not respond to requests for comment. Dr Anderson, however, was happy to see the results in print.
"The company should be congratulated for conducting the study and the journal for publishing it," he said. "Publication of negative and not just positive results needs to be encouraged."
(Reuters Health, October 2011)