On Wednesday February 7th 2007 the FDA approved the over-the-counter sale (OTC) of GlaxoSmithKline's diet drug Alli, the low dose brother to prescription strength Xenical. It is estimated that Alli will be available OTC by this summer. The pleasantly plump and uninformed general public will certainly be pleased; however, there is plenty to be worried about beyond greasy stools and soiled underwear. After all, medical pharmacology always works'"-have we found the incredibly sought after "MAGIC PILL"?
The active ingredient in OTC Alli is 60mg of Orlistat, a gastrointestinal lipase inhibitor. Lipase is a crucial enzyme responsible for the digestion of long-chain triglycerides in the gastrointestinal tract. The purported benefit of lipase inhibition is a resultant 30% decrease in the absorption of ingested fats; thus, leaving the fate of this fraction of your dietary fat to go down the toilet (as fecal matter). Doesn't sound too bad? Well, read on!
There are numerous side-effects associated with fat malabsorption. Our most primitive fitness senses should be on high alert, as we all know that several of our vitamins are fat '"soluble (in case you have forgotten, A, D, E, and K). In most cases vital fat soluble nutrients are flushed out with your fat-laden feces. Other notable acute, but regularly occurring, side effects include, diarrhea, frequent fecal urgency, bloating, fecal incontinence, and anal leakage; all of this and a bleak 1-yr weight loss total that may approximate a mere 5% (Anderson, 2006). In addition, the mode of action of Alli begs for abuse; I wonder how many people are thinking, "Hey, I can eat chicken wings all night and 30% of the deep-fried goodness will be flushed down the toilet!"
A careful review through PubMed suggests that the health concerns of chronic Orlistat dosing may be even worse. It has been well documented in epidemiological and animal studies that diets rich in fat promote colorectal cancer (Morotomi et al., 1997;Newmark et al., 2001), partially due to the high fat content in feces. In a recent article published in Cancer Letters the authors suggest that the increased fat content in fecal matter associated with Orlistat dosing promotes the progression of colonic cancer. This effect is associated with intracolonic changes that are a result of the direct action of high fat levels on coloncytes. In a series of experiments, Britto Garcia et al. observed that in rats Orlistat was associated with increased markers of first stage colorectal cancer, independent of a high fat diet (Britto Garcia et al., 2006). Dr. Sidney M. Wolfe (Director of the Public Citizen's Health Research Group) stated on Wednesday February 7th 2007 that, "This marks the first time, to my knowledge, that the FDA has approved a drug for over-the-counter use despite knowing in advance that the drug causes either cancer or pre-cancerous lesions."
THE FINE PRINT: GlaxoSmithKline advises exercise and diet interventions should be adhered to while taking Alli.
Based merely on the inherent laziness of most humans, the same
complications with adherence to these traditional modalities of weight
loss will prevail in populations using Alli.
In light of such recommendations and potential health risks, Alli may prove not so MAGIC after all. Very few studies have directly compared the efficacy of Orlistat containing products (i.e., Alli or Xenical) with common weight loss supplements. However, in a randomized comparative study it was found that the commonplace "fat-burner", Xenadrine RFA-1 (Cytodine Technologies) was more effective as a weight loss agent than a prescription "fat-blocker" in overweight women (Colker et al., 2002). In fact, in 12 weeks, the Xenadrine group saw 180% more weight loss than the prescription drug group. Indeed, some of the most basic supplements have proven to more effectively promote weight loss when combined with diet and exercise. For instance, supplements that include green tea extract prove time and time again to be very effective in promoting lipolysis, while simultaneously promoting health (see our R&D article on Green Tea Extract). So, why would Americans take the unnecessary health risks and use Alli? Most likely, because it is new, it is "medical", and flushing ingested fat down the toilet implies an easy way to lose weight. Unfortunately, the latter is not the case and may come with serious costs to human health.