Note: The following is a summary of my Skepticamp Toronto 2010 presentation.
I’ve been practicing pharmacy for over 15 years, and it didn’t take me long to realize after I started working that there was a completely different standard for safety and efficacy for herbal preparations and other supplements. That is, they were largely unregulated. Compared to Health Canada’s internationally-respected approval process for drug products, there was no process in place to regulate the supplement marketplace. To ensure consumers fully understood the potential risks of these products, I started to give two warnings to anyone that asked for my advice about these products:
Compared to drugs, there is little regulation of herbal products. Variation could exist between what it says on the label and what it actually contains.
And if they had any medical conditions, or were taking other drugs or supplements I would add:
Compared to prescription and over-the-counter drugs, the information we have on these products is limited. They could have the potential to interact with other medications and medical conditions that we are not aware of.
Until just a few years ago, Canada’s regulatory framework was not equipped to deal with non-drug supplements. Products were either drugs, and were registered as such, or they were food products, and drug regulatory requirements did not apply. A grey area existed and and all kinds of supplements appeared – with no specific regulatory oversight, no defined quality or content standards, and no objective evaluation of the efficacy claims.
Consultation began in the late 1990′s on a new framework to provide some sort of regulation and oversight to these products. In 1998, the Standing Committee on Health issued its report Natural Health Products: A New Vision. The government reviewed the report and accepted all 53 recommendation. (More background here.) The committee made the following comments regarding efficacy claims (we’ll come back to this):
(Chapter 5B): The Committee rejects the suggestion that health claims should be allowed without some form of evidence.
The Committee recommends that:
- NHPs be allowed to make health claims, including structure-function claims, risk-reduction claims and treatment claims;
- Claims be assessed to ensure that there is reasonable evidence supporting the claim;
- The evidence not be limited to double blind clinical trials but also include other types of evidence such as generally accepted and traditional references, professional consensus, other types of clinical trials and other clinical or scientific evidence;
- The evidence required vary depending on the type of claim being made, with different evidence being required for structure-function claims and risk-reduction claims for minor self-limiting conditions than for therapeutic or treatment claims;
- The label indicates clearly the type of evidence used to support the claim.
It sounded very promising. In 2004, the Natural Health Product Regulations (NHPR), under Canada’s Food and Drugs Act, became a reality. Rather than fully regulating these products as drugs, or leaving them virtually unregulated, the NHPR were a regulatory compromise, as recommended by the Standing Committee: Implementing manufacturing quality, safety, labelling, importation, and distribution standards, while significantly relaxing the standards for product efficacy claims. The NHP regulations encompass a disparate group of products including nutritional supplements, probiotics, traditional Chinese medicine, vitamins, herbal products, and homeopathy:
So let’s look at how the regulations have been applied in two case studies – actual products approved by Health Canada as “safe and effective.”
Case Study: Oscillococcinum
Let’s start with a homeopathic product that’s been approved in Canada, as well as countries around the world: Oscilliococcinum. It’s sold as a treatment for colds and the flu. This product is prepared by decapitating a barbary duck, taking 35 grams of its liver and 15 grams of its heart and fermenting it for 40 days. Yes, you read that right:
The product then undergoes serial dilutions (1 part in 100) 200 times in a row, (i.e., 200C). The final dilution is dripped on tablets of lactose and sucrose. How dilute is that? Really, really dilute. It’s been noted that in order to obtain even a single molecule of the original fermented duck, a volume of tablets greater that the mass of the entire universe would need to be consumed. Here is a table showing just how dilute it is:
It is mathematically impossible that there is any of the original fermented goo in the final product. Yet consulting Health Canada’s natural health product database (Search item 80014156 here) Health Canada has approved the product as “safe and effective”, with the labelled medicinal ingredient as “Extract of the liver and heart of Annas barbariae: 200C” and the following recommended use (translated from French):
Homeopathic medicine to relieve flu symptoms: fever, chills, body aches, headaches.
Not surprisingly, there’s no convincing evidence that Oscilliococcinum, like any other homeopathic remedy,is any different than a placebo–exactly what we would expect. There is no active ingredient in Oscilliococcinum tablets. There’s no objective evidence to establish that homeopathy works, yet Health Canada has approved hundreds of products and determined that they’re “safe and effective”.
Case Study: Horny Goat Weed
The leaf of the plant Epimedium sagittatum is the basis for the herbal remedy “horny goat weed.” It’s also approved by Health Canada’s Natural Health Product Directorate (Search item 80015409 here) with the following recommended use:
Traditional Chinese Medicine used to tonify the kidney and fortify the yang, for symptoms such as frequent urination, forgetfulness, withdrawal, and painful cold lower back and knees.
Now I’m a trained health professional and I have no idea what it means to “tonify” a kidney or “fortify the yang”. But presumably this “recommended use” is based on some sort of scientific evidence. Unfortunately, consulting the Natural Medicines Comprehensive Database (paid registration required, sorry) it’s deemed “possibly safe” for some uses and “possibly unsafe” for others. Horny goat weed is used for all kinds of conditions (e.g., impotence, involuntary ejaculation, sexual dysfunction, weak back and knees, arthralgia, osteoarthritis, mental and physical fatigue, heart disease, hepatitis, HIV/AIDS, polio, bone loss, osteoporosis) but there’s no evidence available to suggest it’s effective for any use. Searching Pubmed for clinical trials, there are only two studies, both published in Chinese, and neither are relevant.
The product is noted to have the following cautions:
Contraindicated in patients with fire from yin deficiency. If dizziness, vomiting, dry mouth, thirst or nosebleed occur, discontinue use.
“Fire from yin deficiency?” How is this helpful to consumer seeking science-based information?
This second example reinforces the observation that there is a significant disconnect between what the scientific evidence says about natural products, and what is being approved by the Natural Health Products Directorate. It relates to the efficacy standard that’s applied.
The Efficacy Issue
The implementation of the regulations has resulted in a significant challenge for consumers and health professionals: the efficacy standard is so low, it’s not helpful. Health Canada’s Evidence for Homeopathic Medicines: Guidance Document states that applications for licenses for homeopathic products must include evidence to support the “safety, efficacy, and quality” of a homeopathic medication. If a manufacturer wants to include a recommended use for the product, “evidence” must be provided. Health Canada accepts different levels of evidence, from clinical trials, down to what it calls “traditional use”. Homeopathic manufacturers can use materia medica, which are essentially compilations of anecdotal information. There is no objective evaluation of efficacy in materia medica. Health Canada offers a list of 59 references it will accept, including references that date back to 1834, which was three decades before germ theory was proposed.
With respect to herbal remedies, like horny goat weed, traditional use claims are accepted, which essentially means that if a product has been in use for a specific condition for over 50 years, it’s deemed “effective” for that purpose. If you don’t have documentation, assurance from three people is acceptable:
As an example, three or more herbalists or aboriginal elders may serve as the source of information. Their evidence must provide information supporting the traditional use of the product and the remaining conditions of use (i.e. information on dose, dosage form, route of administration, duration of use and any risk information). They must also indicate that the traditional use of the ingredient extends back to at least 50 years.
While this statement may indeed provide assurance that a product has indeed been in use for a period of time, it offers no objective evidence that the product is effective for any condition. Yet this type of documentation is considered acceptable evidence of efficacy by Health Canada.
Deciphering the label
When it comes to purchasing supplements and natural health products, reading the label is essential. Here’s how to tell the evidence standard that was applied for the product you’re considering. Drugs that meet Health Canada’s safety and efficacy standards for drugs, like prescription drugs and some over-the-counter drug products, will have a DIN number on label. Homeopathic products have a DIN-HM number on the label – so take the labeling with a grain of salt (or sugar), as there’s no persuasive evidence homeopathy is effective, and if it’s sufficiently diluted (12C or greater), you’re unlikely to get a single molecule of the labelled “ingredient” in the product. Products with an NPN number will fall into one of the other categories noted above, including herbal remedies. You can probably be assured that what’s on the label is in the bottle (allowing you to verify any drug interactions or cautions with any conditions you may have). However, given the lowered standard that’s acceptable for efficacy claims, be aware that the “recommended use” may be based on little more than anecdotal information. Ask the pharmacist for evidence to demonstrate efficacy (with that product) or search for evidence yourself. Some products with NPN numbers may be effective for their recommended use, and backed by good science. But it’s not possible to discern this based solely on an NPN number. Finally, products with an EN number are not fully registered yet. I don’t recommend these products, especially if there are approved products available. (More here) Finally, products without any number (DIN/NPN/DIN-HM/EN) haven’t been registered or approved as a natural health product. This means there has been no regulatory approval of the manufacturing process, the safety, and the claims. It appears there may be thousands that remain for sale, even though their sale isn’t permitted under the regulations.
The bottom line for consumers? Despite the original rationale and intent of regulating natural health products, the current framework lacks the regulatory teeth necessary to assure consumers and health professionals that all approved natural health products are indeed “safe and effective”. The regulations bundle products that range from possibly/probably beneficial to those that are effectively placebo sugar pills. Recommended use descriptions could be based on good science, but they could also be based on anecdote – and the standard applied isn’t disclosed. These same regulations don’t require that products be accurately labelled (e.g., homeopathy should properly be labelled to indicate that there are no medicinal ingredients). On balance, registered products are probably safer than unregistered natural health products, but seeing a product with an NPN or DIN-HM does not mean that a product is safe or effective.
Have I changed my caution to consumers, based on the new regulations? Yes, in part. Regulation is now in place in Canada, and if enforcement takes place, all products sold will eventually meet the regulatory standards. So consumers and health professionals should have the assurance that what’s on the label is actually in the bottle. But when it comes to understanding whether these products are actually effective, the regulations come up short for consumers and health professionals. Natural doesn’t mean safe or effective. And the Natural Health Product Regulations don’t change that. Do your homework, ask questions, and look to the scientific evidence.