I first heard of Hoodia last summer, when a radio ad told me it was the new miracle weight loss pill. Since then, I’ve been 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. Today I did a Google search for it and got 14,300,000 hits. 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 as a cure for 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. There hasn’t been a single published study in humans. In fact, there’s only been one study in animals, and that was in calorie-deprived rats that had the stuff injected directly into the third ventricles of their brains to show that it could reverse the chemical changes of calorie deprivation in neurons.
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.”
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 estimates that half of the Hoodia products they test contain no Hoodia at all.
The FTC has received over a hundred complaints. ConsumerLab has concluded that hoodia has not been proven safe or effective, and the quality of products is uncertain. Consumer Reports on Health recommends against taking products containing Hoodia.
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 Fancy Rack for a Bad Back
Have you seen the ads? They’re all over my local newspapers, and they’re probably in yours too. “Who Else Doesn’t Want Back Surgery?” “One of the few doctors in our area to treat serious back pain conditions WITHOUT SURGERY – SAFE – EFFECTIVE – PAINLESS – APPROVED BY THE FDA.” “CORRECTS HERNIATED DISKS WITH NON-SURGICAL DECOMPRESSION,” “Space Age technology,” “86% SUCCESS RATE.”
The ads may include a picture of a big, impressive machine. They may be more restrained, with a cryptic message and a phone number to call for a free report.
Any doctor who treats serious back pain, especially one who operates on ruptured disks, would probably trade a kidney or his first-born son for an 86% success rate. You might ask why they are not all using this miracle treatment. You might wonder why such a successful method has to be advertised directly to the public. You might decide to send in for the free report.
If you do, you will get a package in the mail with material supposedly written by an individual chiropractor who wants to tell you about his personal experience with this wonderful new treatment. One brochure says “Confidential Report,” one has a picture of an astronaut in a space suit. You don’t just get a single mailing; you get a deluge. There are testimonials, offers of free exams, repeat mailings of the same brochures, and warnings that appointments are limited, that you only have 5 days left, and that this may be your last chance to end your back pain once and for all.
It gets really interesting if you answer three different ads from three different chiropractors: you get the same “personal” report with nothing changed but the name of the doctor. It gets even better when the doctor forgets to change the name and leaves in the name of the last guy. And it seems they all forget to proof-read the text, since they all leave in the same egregious errors of spelling, grammar and syntax. I counted no less than 6 mistakes in the citation of a single study – and that was the very study their 86% claim was based on!
It turns out that this miraculous new Space Age treatment is a machine called the DRX-9000, which is nothing but a new-fangled computerized way to apply an age-old remedy: traction. They brag that this machine is approved by the FDA. Well, sort of. A previous traction machine was approved by the FDA, and the FDA considers the DRX-9000 to be just another brand of the same thing, so it got what is called 501(k) clearance, riding in on the coattails of the older device. The manufacturer claims that this machine offers advantages over the older machines, but the FDA considers them equivalent. They were making the same claims for the VAX-D machine 10 years ago. No comparison study has ever been done.
What’s the Space Age connection? Supposedly astronauts found that being in space in no-gravity conditions relieved their back pain and relieved the bulge of disk herniation. I’m still trying to find out which astronauts managed to sneak into space with herniated disks, and whether their medical examiners were fired for missing the diagnosis. I’d also like to know what happens to back pain when the astronaut is subjected to high G-forces on re-entry. I suspect an urban myth, right up there with the story that NutraSweet was originally developed as an ant poison. And the whole thing is just too silly, because you don’t need to go into space to think of relieving stress on a disk by traction – that’s easy enough to figure out right here on Terra Firma. It’s been tried, and it’s been abandoned because it is inconvenient and temporary and makes no difference in the final outcome of patients with back pain.
What about the main claim? “In clinical studies, more than 86% of patients were effectively corrected.” I thought that clinical “studies” meant more than one study, but not in this case. There is only one supporting study. It is not listed in PubMed. It was published in a “throwaway” publication rather than a peer-reviewed journal. It had no control group. Along with traction, patients were given other treatments that might have contributed to pain relief. There was no way to know how many patients would have improved with no treatment; we know that up to two thirds of ruptured disks regress spontaneously over six months. The doctor who ran the study lost his medical license and then lost his job as a law review editor because he was jailed on a felony assault conviction for hiring a hit man to attack his wife. And the most glaring defect was that nowhere in the study did it mention what machine was used! They are making claims for the DRX-9000 based on a study that does not say it used the DRX-9000!
Medicare and insurance companies know traction is ineffective for back pain; they won’t pay for this treatment. Patients have to cough up $5000 or more of their own money for a typical course of treatment. No formal studies have been done, but I talked to a chiropractor who did his own informal study: patients either said the treatment was painful or said they felt better, but only for about a month.
It is mainly chiropractors who are promoting this “new” treatment. Interesting, since the very word chiropractic (from the Greek chiropraktikos) means “done by hand” or “effective treatment by hand.”
I guess that means those chiropractors have recognized that their manipulations are not so effective after all. They’ve essentially given up on their own specialty and are looking for other ways to help patients – or at least to help themselves to a steady income.
Patients with back pain are vulnerable, grasping at any straw to relieve their agony. The truth is that this is an unproven, expensive treatment that may have a small chance of temporary benefit. Those who misrepresent it as a miracle cure could be offered a taste of their own medicine: another traction device used in the Middle Ages that they called the rack.
 MacLean DB, Luo LG.. Increased ATP content/production in the hypothalamus may be a signal for energy-sensing of satiety: studies of the anorectic mechanism of a plant steroidal glycoside. Brain Res. 2004 Sep 10; 1020(1-2):1-11
This article was originally published as a SkepDoc column in Skeptic magazine.