Guest Article
by Leilani Alvarez, DVM, DACVSMR
New York, NY
Dietary supplements comprise a multi-billion-dollar industry. In the United States, more than 50% of adults consume dietary supplements. In the early 2000s, sales of dietary supplements soared in the United States, with an estimated $25 billion in annual sales.
Approximately 1/3 of that spending is on glucosamine/chondroitin supplements, even though multiple studies have demonstrated little to no clinical benefit of these supplements for the treatment of osteoarthritis (OA) symptoms. We know that 69% of Americans suffering from OA take supplements to treat their condition. Given that an estimated 20% of the canine population suffers from OA, we suspect an equal or larger percentage of dogs are receiving joint supplements.
SAFETY AND EFFICACY
Under the 1994 Dietary Supplement Health and Education Act (DSHEA), dietary supplements were classified as a category of food and are not subject to the premarket safety and efficacy testing required by the US Food and Drug Administration (FDA) for pharmaceutical drugs. DSHEA stipulates the manufacturer is responsible for product safety, and claims must be substantiated by evidence that should not be misleading. The FDA is unable to take action against any manufacturer unless it can prove that claims are false and misleading.
Further, unless the manufacturer voluntarily pursues quality assurance and verifiable ingredients, we cannot trust the label regarding a true ingredient list. Products are often not pure and free of contaminants, pesticides, heavy metals or pharmaceuticals.
For example, in 2015 the NY State Attorney General cited 4 major retailers (GNC, Target, Walmart, Walgreens) for fraudulent and potentially dangerous herbal supplements. They found that 4 out of 5 products contained NONE of the listed ingredients on the bottle! In a 2018 Journal of the American Medical Association quality improvement study, analysis of FDA warnings from 2007 through 2016, showed that unapproved pharmaceutical ingredients were identified in 776 dietary supplements, with 157 products (20.2%) containing more than 1 unapproved ingredient.
QUALITY ASSURANCE
In 2007, the FDA issued Current Good Manufacturing Practices (cGMPs) in which the manufacturer is expected to guarantee: Identity, Purity, Strength, and Composition of supplements. Dietary Supplements with a cGMP label must comply with strict manufacturing guidelines and verify their ingredient list.
The equivalent in veterinary medicine is the National Animal Supplement Council (NASC). As part of its ongoing effort to improve and standardize the animal health supplement industry, NASC initiated a Quality Seal Program. The Seal is a way for consumers to know that when they buy a product, they are buying from a reputable company. Obtaining the NASC seal involves a >300-point inspection process, including a rigorous independent facility audit. In addition, products must be manufactured according to cGMPs.
However, it’s important to note that despite thousands of animal dietary supplements on the market, less than 100 are NASC members.
WHAT TO LOOK FOR IN A QUALITY SUPPLEMENT
Practitioners and consumers are faced with hundreds of options for supplements that claim to benefit and support joint health.
Practical advice in choosing a quality product includes:
- Choose a company that has been in business for longer than 10 years. This helps ensure manufacturing processes have been well established and the company is financially sound enough to run quality control measures and enforce them, including potential recalls.
- Look for third-party laboratory verification of product quality and safety such as NASC, cGMP, or USP (United States Pharmacopeia).
- Choose supplements that have been tested not just in vitro, but in vivo with robust randomized controlled clinical trials, ideally in the species you are using the product and for treatment of the same intended condition.
Additional resources include Consumer Lab, which provides independent testing of dietary supplements for a small annual fee (www.consumerLab.com; NOTE, they have only tested a few veterinary brands) and the Dietary Supplement Label Database (DSLD) that is maintained by the National Institutes of Health (www.dsld.nlm.nih.gov).
Also, practitioners should help guide and educate owners regarding searching the internet for new products. Websites that are intended to educate (such as universities, government, or health agency sites) are more reputable than websites maintained by the manufacturer that are intended to sell a product. In addition, consumers are encouraged to verify the validity of listed studies and understand that consumer anecdotes of “miracle cures” can be written by anyone and are generally not verifiable.
REFERENCES
- Liu X, Machado GC, Eyles JP, et al. Dietary supplements for treating osteoarthritis: a systematic review and meta-analysis. Br J Sports Med 2018;52:167-175.
- Vandeweerd JM, Coison C, Clegg P, et al. Systematic review of efficacy of nutraceuticals to alleviate clinical signs of osteoarthritis. J Vet Intern Med 2012;26:448-456.
- Comblain F, Serisier S, Barthelemy N, et al. Review of dietary supplements for the management of osteoarthritis in dogs in studies from 2004 to 2014. J Vet Pharmacol Ther 2016;39:1-15.
- O’Conner A. New York attorney general targets supplements at major retailers. New York Times. February 3, 2015. https://well.blogs.nytimes.com/2015/02/03/new-york-attorney-general-targets-supplements-at-major-retailers. Accessed May 2019.
- Tucker J, Fischer T, Upjohn L, et al. Unapproved pharmaceutical ingredients included in dietary supplements associated with US Food and Drug Administration warnings. JAMA Netw Open 2018;1(6):e183337.
https://www.consumerreports.org/vitamins-supplements/what-usp-verified-and-other-supplement-seals-mean/