Prescription drug sales in Canada amount to roughly $50 billion a year. That’s a lot of money, but the $13 billion pulled in annually by the natural health products industry isn’t small potatoes either. The question is what consumers are getting for that money.
Prescription drugs are stringently regulated, requiring extensive testing and randomized, double-blind clinical trials before approval. While all drugs come with side effects, there has to be a clear demonstration that the risk of these is outweighed by benefits. The situation is different when it comes to “natural health products.” These include vitamins, minerals, herbal remedies, probiotics, enzymes, amino acids and essential fatty acids along with traditional Chinese and Ayurvedic medicines. Regulations here are much less stringent because they are not intended to treat serious disease. By definition, “natural health products are composed of substances that can be derived from plants, animals, microorganisms or marine sources and are used to restore or maintain good health.” What is meant by “restore or maintain good health” is open to interpretation.
Unlike for dietary supplements in the U.S., the sale of a natural health product in Canada requires an application for a product license. If that is granted, a Natural Product Number (NPN) is issued and must be displayed on the product’s label. Since 2004, some 90,000 such licenses have been granted but that does not mean they are all being produced for sale. The exact number available from health food stores, pharmacies and the internet isn’t known, but it is in the many thousands. Given that the NPN is officially issued by Health Canada, consumers naturally assume that the product has been proven to be safe and effective. That is not exactly the case.
Safety is not an issue because here the requirements are quite strict. Evidence has to be submitted that the product is free of contamination from pesticides, heavy metals, pathogenic microbes and their metabolites. The label must include a list of ingredients, and information about dosage and duration of use must be provided. Cautionary statements as well as a listing of risks must be included on the label and production must be in an approved facility.
Now for the efficacy question. Here, the requirements are far less stringent than for prescription drugs. In most cases reference to one or more of Health Canada’s monographs that are publicly available is enough to obtain an NPN. These monographs are documents that have been compiled over the years and describe the properties of potential drug ingredients, their conditions of use, and claims that can be made. For example, the Health Canada monograph for the herb ashwagandha states that “it has been traditionally used in Ayurveda to balance aggravated Vata.” Vata is one of the vague “humors” that according to Ayurvedic medicine cascade through the body and determine health, a belief that lacks scientific evidence. The monograph also states that ashwagandha is “used in herbal medicine as an adaptogen to help increase energy and resistance to stress.” Adaptogen is an ambiguous term to describe substances that help maintain the body on an even keel. In any case, that a substance has been used as an adaptogen is not evidence of efficacy, but it is enough to obtain an NPN.
Acai berry extracts have also been licensed and can feature an NPN. The monograph that was referenced in order to obtain a license states that “acai is a source of antioxidants that help fight oxidative damage to cells caused by free radicals.” Oxidative damage due to free radicals produced as a byproduct of respiration is a real thing, but there is no evidence that oral antioxidants have any effect on health. We do know that foods that are rich in antioxidants, mainly fruits and vegetables, are associated with good health, but studies using isolated antioxidants as supplements have not shown the expected benefit. Fruits and vegetables contain numerous compounds, and it may be their synergistic effect that makes for good health. However, the theory about antioxidant action against free radicals was enough to obtain an NPN.
The herb echinacea has been granted an NPN based on submitted scientific publications that show some evidence of benefit for the treatment of the common cold. This has allowed the label to claim that it “helps fight colds and upper respiratory tract infections”. However, there are many studies in the literature that do not show any such evidence. Similarly, ginkgo biloba supplements have been granted an NPN based on cherry picked studies that show some mild cognitive benefit while the majority of studies do not corroborate this effect. If no monograph or studies exist for an ingredient, then the applicant has to provide some evidence that may take the form of traditional use in pharmacopeias, licensing in other countries, or clinical studies of some type.
In summary, natural health products in Canada can be assumed to be safe when used according to label instructions, but the issuing of an NPN does not mean that the specific product has been shown to “maintain, restore or improve health.” It should be realized that an NPN can be obtained without any requirement of evidence from human clinical trials. While false claims on a label can result in government action, some supplement manufacturers make outrageous claims online about weight loss, wrinkle removal, arthritis treatment or improved immune health.
Unfortunately, currently there is no legislation requiring supplement manufacturers to make Health Canada aware of any reports they may have received of adverse reactions. Also, there is no systematic verification that what is listed on a label is really in the product. Random checking has revealed that products can contain more or less of an ingredient than the dosage stated on the label.
We would likely be better off if at least some of the 13 billion dollars a year that consumers spend on natural health products were donated to medical research.
