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Weight Loss Customers Are Being Hoodia-Winked

I first wrote about Hoodia in my “SkepDoc” column in Skeptic magazine (Vol. 13, No. 1, 2007).  The following is adapted from that column with an update from new research revealing that it doesn’t work and that it causes worrisome side effects.

I first heard of Hoodia in 2006, when a radio ad informed me that it was the new miracle weight loss pill. Shortly after that, I started seeing ads for Hoodia everywhere. Anna Nicole Smith took it. It was featured on Oprah.  Lesley Stahl went to Africa to taste the plant on 60 Minutes. There are nearly 40 competing brands of pills, a patch version, and even a Hoodia lollipop. It seems to have taken the world by storm; but it’s not new.

Hoodia gordonii is a cactus that grows in the deserts of southern Africa, and the San people have traditionally used it as an appetite suppressant, thirst quencher and to treat severe abdominal cramps, hemorrhoids, tuberculosis, indigestion, hypertension and diabetes. The claim is that it banishes hunger and thirst. What is the evidence? At this point it’s strictly anecdotal. Skinny Bushmen report it relieves hunger pangs in starvation conditions on long hunts; we don’t know what happens if it’s used by lazy fat people with access to food. Before the new study, there hadn’t been a single published study in humans.

The African Council for Scientific and Industrial Research isolated the active ingredient, P57, in 1977. They granted a license to Phytopharm, who collaborated on research with the pharmaceutical company Pfizer.

Pfizer eventually gave up on Hoodia due to the difficulty of synthesizing P57, and released their rights to it.  Jasjit Bindra, Pfizer research scientist, said there were other components in Hoodia that damaged the liver and could not be easily removed from the supplement. He advised:

Until safer formulations are developed, dieters should be wary of using it.

In 2008, Unilever dropped its plans to market a Hoodia product after spending over 4 million pounds on research.  Phytopharm continued to investigate it. Meanwhile, Hoodia is readily available as a diet supplement.

As well as being scientifically unsupported, Hoodia is politically incorrect. For one thing, it has been “stolen” from its original owners, the San people. Legally, it can only be exported under license, to guarantee patent rights and return a portion of the profits to the San people.  Some of the trade in Hoodia is clearly illegal: at least one poacher has already been arrested. For another thing, Hoodia is a protected species. It grows wild, only in a small area, and takes several years to mature. It has not yet been successfully cultivated. Uncontrolled harvesting could wipe it out.  There’s not enough available to supply all the products said to contain it. Products that have been tested have contained between 0.1 and 0.01 percent of the active ingredient claimed.  One testing company estimated that half of the Hoodia products they test contain no Hoodia at all.

The FTC had received over a hundred complaints as of 2007. ConsumerLab concluded that Hoodia had not been proven safe or effective, and the quality of products is uncertain. Consumer Reports on Health recommends against taking products containing Hoodia. Even herb-friendly Andrew Weil recommends caution on his website.

I concluded my 2007 article with:

You have no way of knowing whether you’re getting the real thing; and if you are, you may be ripping off the San people or endangering a species. You have no way of knowing if the real thing works or if it’s safe. Other than that, it’s probably a great product!

A 2011 review found that:

Publications based on scientific studies of key aspects such as in vivo biopharmaceutics, the biological activity of all chemical constituents, clinical efficacy, and especially safety are insufficient or completely absent causing great concern as H. gordonii is one of the most widely consumed anti-obesity products of natural origin.

Finally, A Human Study

Now a new study published in October 2011 in the American Journal of Clinical Nutrition by Blom et al. has revealed that it doesn’t work and that it causes side effects. It was a randomized placebo-controlled double blind clinical study of 49 healthy overweight women. They were carefully monitored as inpatients, given either an H. gordonii extract or a placebo for 15 days after a 4 day run-in period, and were allowed to eat as much as they wanted. The researchers took a lot of precautions such as not letting subjects watch each other eat and standardizing the food so they could accurately measure calorie intake. I was impressed that the study was well-designed, carefully executed, and fully described even down to the brand and model of the machine used to do EKGs. The authors were employees of Unilever and Phytopharm, which holds the worldwide license for the application of H. gordonii extract in weight management products. The study results are a let-down for Big Pharma and are just the opposite of what might have been expected from researcher bias.

They found no significant difference in calorie intake or weight loss. They found significant and sustained increases in blood pressure, pulse, heart rate, bilirubin, and alkaline phosphatase. And they found a significantly higher incidence of side effects including nausea, vomiting, and disturbances of skin sensation.  No serious reactions occurred, and a number of other tests (other liver function tests, hematocrit, cholesterol, EKGs, etc.) showed no significant change. Although subjects were not told to reduce their food intake, both groups ate less and lost an average of 1.2 kg, showing that just being enrolled in a study had an effect on behavior.

Conclusion

At this point I think it is reasonable to give up on H. gordonii.  It doesn’t produce weight loss, and it causes a number of adverse effects. There is no miracle product that will magically decrease your hunger and melt the pounds off. Don’t be Hoodia-winked.

Posted in: Clinical Trials, Herbs & Supplements

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25 thoughts on “Weight Loss Customers Are Being Hoodia-Winked

  1. DevoutCatalyst says:

    As Richard Nixon once said, “I am not a cactus”.

  2. rjkmd says:

    Hoodia gordonii is NOT A CACTUS. Cacti are native only to the new world, although they have been introduced all overte worls, primarily the Prickly Pear type. Hoodia gordonii is “in the flowering plant family Apocynaceae, under the subfamily Asclepiadoideae.[1] They are stem succulents, described as “cactiform” because of their remarkable similarity to the unrelated cactus family”. A minor point. Hoodia is a genus of succulent plants in the family Apocynaceae. There are about 20 species in this family but “cactus” like Gordonii is the one that contains the natural appetite suppressant. It can also be used to maintain a high energy level. The plant was first discovered in the semi-deserts of Southern Africa namely Boswana, Namibia Angola and South Africa. It produces odiferous flowers that attract flies, which pollinate them.

  3. “P57″ would appear to be an active ingredient in search of an action.

  4. JPZ says:

    @Harriet Hall

    One other thing I found impressive about the Blom, et al. study was how much work went into standardizing the H. gordonii extract by HPLC (ref. 6 in the paper). And I agree, Blom, et al. is a good study showing no efficacy of H. gordonii.

    What you didn’t mention was that the paper itself cites previous Unilever internal research showing H. gordonii efficacy in rats and humans. It is unpublished data, so it doesn’t carry that much weight compared to the Blom, et al. paper, but it does point out that there may be evidence of efficacy mixed with evidence of ineffectiveness. As a scientist, I would ask, “Why is the data inconsistent?” As to why did Unilever stop working on H. gordonii, my speculation is that senior management got tired of waiting to market the product and put a go/no-go decision on the Blom, et al. study.

    There are other things Unilever could have done (and maybe already did). Using a different extraction process on H. gordonii might have enriched the efficacious molecules and reduced the harmful ones. Also, the Blom, et al. study had obese subjects eating ad libitum while using Hoodia. This is a high bar to set for a weight loss product – obese people with poor eating habits eating what they want. A different clinical trial model would be subjects working to lose weight by one method and testing whether Hoodia augments the weight loss process. So, I wouldn’t consider Hoodia research dead, but it still has a long way to go if anyone wants to pick up the pieces. Hopefully they will do it in a much more sustainable and culturally respectful way.

    That said, given the present state of research, I don’t think I would recommend its use for weight loss.

  5. Scott says:

    Also, the Blom, et al. study had obese subjects eating ad libitum while using Hoodia. This is a high bar to set for a weight loss product – obese people with poor eating habits eating what they want. A different clinical trial model would be subjects working to lose weight by one method and testing whether Hoodia augments the weight loss process.

    I would have to wonder whether this was a deliberate choice. Something that can augment weight loss already being worked at normally is more plausible. But if it could produce weight loss with no additional effort, well, that would be mind-bogglingly lucrative. Forget Lipitor and Viagra, that would be a blockbuster beyond compare.

  6. cervantes says:

    What I’m not getting is what made them decide that P57 was the “active” ingredient in the first place?

    On the other hand, it’s curious that a product that induces nausea, vomiting, and increased heart rate does not result in weight loss.

    I agree with Scott that a trial of a weight loss product should at least have subjects who want to lose weight. But again on the other hand, the adverse effects would seem to rule this one out.

  7. JPZ says:

    @Scott

    “I would have to wonder whether this was a deliberate choice.”

    Maybe they were shooting for the stars with this study, but even orlistat is supposed to be used as part of an overall weight loss program (with attendant “penalties” if you don’t cut your dietary fat). I don’t think regulatory authorities (EFSA, FDA, etc.) would allow you to make APPROVED weight loss claims without including “as part of a weight loss program including regular exercise and a low-calorie diet.” Also, I generally wouldn’t think of Unilever as doing an all-or-nothing study (unless my speculation about funding is true) – they have some great scientists there.

  8. JPZ says:

    @cervantes

    “…it’s curious that a product that induces nausea, vomiting, and increased heart rate does not result in weight loss.”

    Ooooh, good point!

  9. Scott says:

    @ JPZ:

    I’m certainly speculating, but it would be one explanation. And one which could be eminently logical if it were determined that only in the best case would it be adequately profitable. (Piling on even more speculation.)

    I’d also expect that the regulators would have to allow a weight loss claim without such inclusion IF such claims were backed by good evidence. If the data showed that you actually COULD safely and effectively lose weight from a pill without attendant lifestyle changes, it would simply be false to include such a statement.

  10. Scott says:

    Or perhaps I should say misleading instead of false. Apologies for the error.

  11. MoonJewel says:

    I would point out that the whole selling point for Hoodia is that it is an appetite suppresant. It is supposed to make you not be hungry so you won’t eat. We all know that the best way to lose weight is through diet and exercise. But they are selling Hoodia as the “take this and you will lose weight without doing anything” pill. So, in order to properly test the product, they’d have to allow people to follow their normal habits. At least, that’s what I gleaned from the article. In all of those ads, they include the “along with diet and exercise” statement because it’s the diet and exercise that actually makes people lose weight. Nothing else does (or at least, has not been clinically shown to, except for that one pill that is FDA approved because it prevents you from absorbing calories from fat).

  12. Thanks for the heads up on this supplement, Harriet Hall. I am not one for weight loss supplements myself, but they do seem to pop up in conversation, so it’s good to have an overview of the effectiveness, side effects and the negative environmental, poaching aspects, to share.

  13. ConspicuousCarl says:

    DevoutCatalyst on 08 Nov 2011 at 6:07 am

    As Richard Nixon once said, “I am not a cactus”.

    It’s so weird, looking back at historical statements which we believed at the time but now know to be false.

  14. Evil Mammoth says:

    There is no miracle product that will magically decrease your hunger and melt the pounds off.

    Cigarettes.

  15. JPZ says:

    @MoonJewel

    “take this and you will lose weight without doing anything”

    I imagine that there are irresponsible companies making nearly that exact claim, but Unilever is the company that did this study. If you can find an example of Unilever making such a claim, I would encourage you to share it on SBM. When I was a kid the phrase was “bet you a nickel,” but I don’t think PayPal can transfer that small of an amount. ;)

    “Nothing else does (or at least, has not been clinically shown to, except for that one pill that is FDA approved because it prevents you from absorbing calories from fat).”

    Google “weight loss” and “Am J Clin Nutr.” Your statement has no basis in fact.

  16. ConspicuousCarl says:

    JPZon 09 Nov 2011 at 11:10 am

    @MoonJewel

    “take this and you will lose weight without doing anything”

    I imagine that there are irresponsible companies making nearly that exact claim, but Unilever is the company that did this study. If you can find an example of Unilever making such a claim, I would encourage you to share it on SBM.

    Unilever didn’t say it because they aren’t selling it at all:

    “In 2008, Unilever dropped its plans to market a Hoodia product ”

    As far as can be gathered from Hariet Hall’s post, Unilever is not the one to be accused of making any claims at all.

  17. JPZ says:

    @ConspicuousCarl

    “Unilever didn’t say it because they aren’t selling it at all:”

    Pardon my being a bit too vague. Perhaps I should have said “…find an example of Unilever making” [a similar] “claim” [on any product]. Unilever is the second largest food company in the world (I think they are still second) and probably have thousands of claims on its various products.

    Considering how MoonJewel phrased this:

    “But they are selling Hoodia as the “take this and you will lose weight without doing anything” pill. So, in order to properly test the product, they’d have to allow people to follow their normal habits.”

    The “they” testing the product and the “they” hypothetically making the claim would appear to be the same, i.e. Unilever. I believe it is a “hasty generalization” to take this hypothetical (but illegal if actually put on a label) claim and create a “fallacy of composition” argument to include Unilever, a much more responsible company. Along with the statement about “normal habits,” I felt MoonJewel’s comments should be discussed since s/he doesn’t seem to understand nutrition research, nutritional product companies or nutritional product regulation. Many commentators on SBM do likewise when someone makes misleading or incorrect comments about the drug industry, yes?

  18. kathy says:

    Hoodia is a genus of some 20 species, all desert-living succulents and all slow-growing and very, very difficult to grow commercially. One species, H. gordonii. is used as an appetite suppressant. H. gordonii and some of the others occur in good-size populations, rather like the American bison or the passenger pigeon which, as we know, means they can be plundered at will without any effect on their numbers. All species are protected plants in S Africa and Namibia and ten are recorded as “Threatened” in the Red Data List.

    Earlier this year I went out with some medicinal plant researchers to help them collect some 40 species of local plants (not Hoodia before you ask, and none of them particularly rare) for their research.

    Now let me tell you some raw facts: they arrived with a list of names, some of them non-existant (!!) and several of them dead wrong. Once we had sorted that out we could look for likely localities to go to.

    They had no idea how they were going to identify the plants they wanted so I went onto the Net (once I’d cleaned up the list of names … without names you haven’t any way to find anything on the Net) and downloaded photos for them to use; also made up short descriptions.

    I insisted that they must keep voucher specimens of everything they aimed to test … they had never heard of the concept, but they were compliant … if rather impatient, rather like children being told to wash their hands.

    Three days that week I was able to go with them; the other two days they went out alone and several of the plants they came back with were misidentified. Not just as to species (which can be tricky), but totally 100% wrong … so my photos and descriptions weren’t good enough! They had to either abandon those species for testing, or go back and re-collect. However, at least they didn’t waste time and money on testing the wrong thing. On Friday I waved them off home with their bags full of, hopefully, the right things.

    I must say it was a most interesting week. These were bright, well-educated young men with a budding career in plant-based medicine and laboratory analysis methods … which I’m sure they knew plenty about. I’m not running them down or saying they were stupid; they weren’t. But what I want to say is: If these guys couldn’t identify the plants they collected, I wonder if some poverty stricken local going out to collect a bag of Hoodia to sell for a few rands, will distinguish between the species? Protected species will be picked if they are in the area, not only H. gordonii.

    The other thing that made me wonder, was: how reliable is some medicinal-plant research when it may be based on dubious identifications? And no voucher specimen to double-check later if there is a query …

    If I was to go on ranting, this here Africa-based botanist would say sharp things about spoilt rich overfed people stripping the earth because they don’t want to cut down on what they eat or walk rather than ride everywhere in their cars. But I will be restrained and stop here … {oooooo, difficult}

  19. JPZ says:

    @kathy

    I really enjoyed reading your post! You respected your visitors while making it clear that they did not know what they were doing while in South Africa. How did you wish for them to document and confirm voucher specimens? I know that collected versus tested samples can be verified by DNA fingerprinting, but the phylogenetic issues of tested versus sourced are something I do not know much about.

    The study that Harriet Hall referenced used HPLC profiles to characterize the validity and concentration of their H. gordonii for testing. It is reference 6 on the paper.

    As for “spoilt rich overfed people,” I think that may be most unkind of you. A good friend of mine works in international nutrition. She worked in Haiti quite often over the years (mostly before the earthquake). When she arrived, her friends would greet her telling her how healthy and “rich” she looked. When she asked, they would tell her that only people as “healthy” as she was were rich and ate “rich” food. Now, this woman was an ice climber in the winter and was maybe 3-4 kilos above her “ideal” weight for health (ice climbing is a winter-only sport, so she built up 3-4 kg of body fat in the summer season). What the Haitians found remarkable was that she had ANY body fat. But, if you had some rather obese visitors huffing and puffing their way for less than a kilometer, I can certainly understand your disdain. I just wanted to share that perspectives can differ.

    My best wishes to you in all your work!

  20. JPZ – I read it that Kathy was talking about overfed, rich and spoilt consumers who are taking the herb in order to lose weight and therefore creating a demand for a protected species, not the researchers.

  21. kathy says:

    JPZ – Michele is correct, I wasn’t referring to the researchers. I was just having a li’l rant about people who want to get slim the quick ‘n’ easy way, without having to exercise or control their eating, i.e. take some herbal pills, and no quesions asked whether the herb was “harvested” from wild populations, or whether this usage is sustainable. (I MUST NOT RANT!! I’m feeling sick and sore right now today because of what is being done to our rhinos: horns, aphrodisiacs, rich guys for the use of. {mutter, mutter …})

    I don’t know what methods the researchers used to profile the 40 or so species they collected. Not my field at all … I’m a herbarium curator. I rely on sight and experience to ID plants … I might tell you at a glance that the plant you just spent half a day collecting 4 kg of is, say, Plantago major, and not P. lanceolata like you thought. They look similar but they are different species. No need then to do HPLC or any other test, you can put it straight away into the dustbin.

    However, when one doesn’t have a taxonomist to tell you, “Chuck it out”, it’s a good idea to at least have a pressed dried specimen in a herbarium, where anyone can go see it or ask to borrow it, and so check that the species was correctly named in the first place. Then if you did find that your “Plantago major” has an effect on, say, plantar warts, and subsequent researchers don’t find that effect, it’s simple to check whether it wasn’t maybe P. lanceolata that they inadvertently worked on.

    Don’t know that this answers your question? Or even if I properly understood what it was.

    Bless their cotton socks, but they had a grumpy old dame to deal with, and one moreover who was highly sceptical of their herbal cures and ayurvedic medicine … too much reading of Science Based Medicine and similar websites.

  22. JPZ says:

    @kathy

    Oh my! I completely misunderstood what you meant! I am currently working on a project related to famine relief, so my views about body fat and mortality are a little skewed right now. I hope you can forgive me. As you can see, micheleinmichigan is often our resident voice of reason regarding motives.

    As for the majestic (and incredibly dangerous) rhinos, I read an interesting news report that the harp seal population was resurging in several areas. With the advent of Viagra, the demand for the seals’ male parts dropped sharply. When Viagra goes generic, let us hope that rhinos benefit as well!

    You answered my question quite well. I had a course in botany in college, and your mention of a herbarium made it very clear what you meant. My instructor was a taxonimist (sp?) as well, and he went into incredible detail about species identification. In one of our outdoor lab tests, a few students were having trouble identifying a cottonwood tree. Then, he reached out and shook one of the limbs, and that characteristic clatter of the leaves against one another immediately ensured that no one missed that question on the test. I know that doesn’t have anything to do with this discussion, but I thought you might be entertained by the example!

    Thank you for your insights!

  23. Calli Arcale says:

    “With the advent of Viagra, the demand for the seals’ male parts dropped sharply. When Viagra goes generic, let us hope that rhinos benefit as well!”

    The current issue of Smithsonian Magazine has a heart-breaking article about rhinos and the herculean measures being employed to try to protect them. Apparently it’s actually a myth that people use the horn to cure impotence. The biggest consumers until the 80s were actually Arabs who prized it for their traditional dagger handles (and who had a great deal of disposable income to flaunt). That became less of an issue as more and more of them adopted synthetic alternatives. And then China moved to officially remove rhino horn from the list of official traditional Chinese medicines. (It was used for various common but mild and nonspecific complaints such as stomachache and fever.) But then, a few years ago, a rumor broke about an anonymous Vietnamese businessman with liver cancer who was cured after taking crushed rhino horn. No identifiable details, of course; it follows classic urban legend format. But demand for rhino horn skyrocketed. They’ll kill infants for their tiny nubs of horn. They’re even robbing museusm, taking the horns right off of taxidermied specimens, and the prices are so high that there are people involved in the trade at every level — even owners of ranches which have agreed to protect rhinos, licensed rhino hunt operators, rangers, *scientists*, veterinarians…. There are bad apples in all of these groups, making it nearly impossible to stop the slaughter.

    But it has nothing to do with impotence. So alas, Viagra will not save the rhino.

  24. kathy says:

    The western black rhino (a subspecies of the black rhino) became extinct this year … that’s official. However, for some amazing pictures of conservation methods, do take a look at http://www.newscientist.com/blogs/shortsharpscience/2011/11/black-rhinos-airlifted-by-thei.html … it’s not on topic, apologies to Dr Hall et al … I’m finished now I promise! No more postings.

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