GSK filed the petition at the end of last month, together with the American Dietetic Association, The Obesity Society and Shaping America's Health, an association for weight management. It maintains that obesity and overweight are significant risk factors for certain diseases, and so products promoting weight loss should be treated as drugs. However, the petitioners also claim that "there is no credible evidence whatsoever to support any type of qualified health claim for a weight loss supplement". Qualified health claims are those based on emerging evidence for the relationship between a food or supplement and a reduced risk of disease. Because the evidence is not well enough established to meet the significant scientific agreement standard, this type of claim must include qualifying language to indicate that the evidence supporting the claim is limited. No science…? GSK and the other petitioners maintain that during the past decade there have been a number of reviews of scientific literature surrounding weight loss supplements. "Each of these studies concluded that there is little, if any, evidence to support the efficacy of supplements marketed for weight loss," writes the petition. The reviews referenced include:
Dwyer JT, Allison DB, Coates PM. Dietary supplements in weight reduction. J Am Diet Assoc 2005 ;105(5 Suppl1):S80-6. (Exh. 34)
Saper RB, Eisenberg DM, Phillips RS. Common dietary supplements for weight loss . Am Fam Physician 2004;70:1731-8. (Exh. 35)
Pittler MH, Ernst E. Dietary supplements for body-weight reduction: a systematic review. Am J Clin Nutr 2004;79:529-36. (Exh. 36).
Lenz TL, Hamilton WR. Supplemental products used for weight loss . J Am Pharm Assoc 2004;44:59-67. (Exh. 37).
Supporting evidence However, most dietary supplements for weight loss are not marketed with qualified health claims under NLEA, but with structure/function claims under the 1994 Dietary Supplement Health and Education Act (DHSEA). There is a general consensus that - although not all supplement ingredients have the same level of supporting evidence - there are some that are undeniably well-researched. These include green tea polyphenols, CLA, Hoodia gordonii, DHEA, hydroxy-methylbutyrate (a metabolit of leucine), and chromium picolinate. On the other hand, other ingredients such as L-carnitine, chitosan, and calcium (with dairy) still have only limited supporting data. According to Mark Blumenthal, founder and executive director of the American Botanical Council, it all depends on where the bar is set. "Different reviews have concluded that there is little high quality clinical evidence supporting many of the ingredients sold in dietary supplements intended as aides for weight loss," he told NutraIngredients-USA.com. "But it's one of those classic questions: how much information do you need? There is a growing body of evidence suggesting that a number of safe dietary ingredients when combined with dietary modification and exercise might provide some adjunct support in the weight loss process." "The real problem here is whether it's in the public's interest to 'diseasify' the entire weight loss category, thereby virtually removing many safe options for consumers to consider when trying to manage their weight," he said. It is also worth noting that weight loss is a relatively young segment for the supplement industry, and as in every emerging market the supporting science takes time to arrive - but this does not mean that it has not been pursued. Company efforts Indeed, some companies such as Lipid Nutrition, Cognis and DSM have invested heavily in the science to support the efficacy of their products in this area. A study funded by Lipid Nutrition, for example, was published in February in the BioMed Central journal Lipids in Health and Disease. The peer-reviewed study was designed to complement existing research on Korean pine nut oil, which is the focus of its weight loss ingredient PinnoThin. Last May, a randomized, placebo-controlled, double-blind trial provided additional backing for DSM's proprietary ingredient Fabuless.The study, which showed that Fabuless stopped weight gain after weight loss. added significant support to the weight management potential of the ingredient, said to work by encapsulating particles of palm oil in oats, which are then formulated in a novel emulsion. Pursuing the pirates However, the bane of the weight loss category for dietary supplements have been the numerous bogus products that have squeezed their way into the marketplace, and that have damaged the reputation of the scientifically sound products. This is also partly the reason why the US Food and Drug Administration (FDA) as well as the Federal Trade Commission (FTC) have weight loss products high on their list of enforcement priorities, and have clamped down on increasing numbers of such bogus products over the past year. More weight loss focus NutraIngredients-USA.com will examine the petition in more detail, with particular attention to the weight loss supplement ingredients it highlights. In addition, we will provide an overview of the weight loss market, and the drug-supplement conflict. To access yesterday's article on the GSK petition, which includes a link to the petition, please click here. If you would like to comment on these articles or on the petition, please e-mail lorraine.heller'at'decisionnews.com