Page 681 - Small Animal Clinical Nutrition 5th Edition

Osteoarthritis 705

Box 34-1. All Nutraceutical “Chondroprotective Agents” Are Not Created Equal.
VetBooks.ir Veterinary nutraceuticals have been defined as “a non-drug sub- panies has since produced a re-formulated product that did pass

stance that is produced in a purified or extracted form and admin- Consumer Lab testing. Glucosamine hydrochloride, unlike chon-
istered orally to a patient to provide agents required for normal body droitin sulfate, is much more likely to be present in the amounts
structure and function and administered with the intent of improv- indicated on product labels. Information about specific products and
ing the health and well-being of animals.” Because the term testing procedures can be accessed at the Consumer Lab website
nutraceutical has no regulatory definition and is not recognized by for a fee. Because of these inconsistencies, consumers are cau-
the FDA, these products are not subject to a pre-market approval tioned against extrapolating results from clinical and experimental
process. As a result the safety, efficacy and manufacturing quality studies comparing one product to other similar products. Based on
of these products cannot be ensured and there is evidence that this this information, when prescribing nutraceuticals, preference
lack of regulatory oversight should be of concern to consumers. should be given to those products whose quality assurance and
In the United States, although there is no mandatory regulatory efficacy can be verified.
oversight, manufacturers of nutraceuticals can voluntarily submit
their products for quality assurance. A variety of independent The Bibliography for Box 34-1 can be found at
groups such as Consumer Laboratory (www.consumerlab.com) and www.markmorris.org.
the Institute for Nutraceutical Advancement
(www.nsf.org) or trade associations such as the
National Animal Supplement Council (www. Correlation between price and percent label claim of chondroitin sulfate
in 32 products in the market using the Phototrode Titration method.
nasc.cc) provide independent quality assurance
testing and certification programs. The two sub- 110
stances most commonly used for treatment of 100
osteoarthritis in veterinary medicine are glu- 90
cosamine HCl and chondroitin sulfate either alone (%) 80
or in combination. Chondroitin sulfate is an expen- 70
sive ingredient of many “joint” targeted products claim 60
and serves as an example of the need for careful 50
evaluation of these unregulated products. Label 40
A 1999 study partially funded by Nutramax 30
Laboratories found that 26 of 32 (81%) commer- 20
cially available human products contained less than 10
90% of the chondroitin sulfate stated on the label 0 $0.50 $1.00 $1.50 $2.00 $2.50 $3.00 $3.50 $4.00 $4.50
and 17 (53%) of those products contained less
than 40% of label claim. This study documented
that products costing ≤$1/1,200 mg chondroitin Price in retail dollars per daily dose of 1,200 mg chondroitin sulfate
sulfate were critically deficient; on average less
than 10% of the label claim. Interestingly, expense
did not guarantee content because several of the most expensive
products also contained less than 10% of label claim (Figure 1). Figure 1. Relationship between products’ label claims and standard
ConsumerLab.com (accessed 11/16/06) found similar problems retail prices. (Adapted from Adebowale AO, Cox DS, Liang Z, et al.
with glucosamine HCl/chondroitin sulfate combination products. Analysis of glucosamine and chondroitin sulfate content in marketed
Initially, on November 2, 2003, two of three veterinary combination products and the Caco-2 permeability of chondroitin sulfate raw
products evaluated were found to have no chondroitin sulfate materials. Journal of the American Nutraceutical Association 2000;
despite each displaying a “guaranteed analysis.” One of these com- 3(1): 37-44.)

nificant pain relief (Clegg et al, 2006). The authors also noted jective methods of assessment, in vitro testing or testimonials.
that the elevated placebo response seen in this study may have Two studies evaluated the efficacy of supplements containing
dampened the ability to differentiate among the treatments the combination of glucosamine/chondroitin sulfate in client-
(60% of patients receiving placebos had at least a 20% decrease owned dogs with naturally occurring osteoarthritis compared to
in pain scores after 24 weeks) (Clegg et al, 2006). These stud- positive controls.These two trials evaluated 106 dogs with con-
ies suggest that glucosamine and chondroitin sulfate may offer firmed osteoarthritis. Nonsteroidal antiinflammatory drugs
clinically relevant reductions in pain for some patients with (carprofen and meloxicam) were used for positive controls. One
osteoarthritis. However, despite a large number of clinical trails study evaluated ground reaction forces and subjective owner
in human medicine, there is still no consensus about the effec- and veterinary evaluations in 71 dogs randomized to receive
tiveness of these compounds. In veterinary medicine, there is a meloxicam, carprofen, a combination glucosamine/chondroitin
lack of consensus and a lack of clinical trials to evaluate. sulfate product or placebo (Moreau et al, 2003). After 60 days,
In veterinary medicine, claims of efficacy for glucos- dogs in the meloxicam and carprofen groups had improved
amine/chondroitin sulfate supplements are often based on sub- ground reaction forces and clinical improvement. Owners