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The False Reassurance of Dietary Supplement Regulation

Canada and the United States have two different approaches to regulate the sale of natural health products, and neither is scientifically rigorous

If you are Canadian, you may have seen the letters “NPN” followed by a series of numbers on the packaging of a health product you picked up at the pharmacy, things like vitamin supplements, echinacea, and probiotics. You may even know that this number is given by our regulatory agency, Health Canada, and you may feel relief that these products are being licensed only after their safety and effectiveness have been evaluated.

If you are American, you may prefer the borderline unrestricted market you have, where dietary supplements are barely regulated at all.

Neither system is perfect, and shameful products are allowed to be sold in both markets. If you think a Health Canada number on the packaging is reassuring, keep reading.

Canada versus the United States

While both countries are allowing the sale of supplements of dubious effectiveness, there are important differences in how these products are regulated on either side of the border. They even have different names.

In Canada, they are known as natural health products (NHPs). In America, they are called dietary supplements. These two categories are not, however, identical. Canadian NHPs include homeopathic preparations—based on the pseudoscientific belief that something which causes a disease will also cure it, and that its curative power is increased by diluting it—whereas American dietary supplements do not. A dietary supplement must be something that is taken by mouth, whereas NHPs also include creams and sprays, for example.

North of the border, NHPs must be accompanied by a health claim; to the south, dietary supplements can make certain claims but are not forced to.

The most significant difference, however, between our two regulatory systems is that the Food and Drug Administration (FDA) in the United States does not oversee dietary supplements. The agency states that it is “not authorized to approve dietary supplements for safety and effectiveness before they are marketed.” In a separate document, they note that they “often do not know when new products come on the market,” meaning that the FDA is “not able to keep a complete list of all dietary supplements sold in the United States.” By comparison, NHPs are regulated by Health Canada and must be licensed. This contrast in approaches is explained, in part, by how the two countries think of these products. In Canada, they are seen as drugs; in the US, they are a subset of food.

O Canada

Natural health products sold in Canada fall under the Natural Health Products Regulations, which came into force in 2004. Initially, NHPs carried a DIN or Drug Identification Number, but since 2010 these DINs, reserved for actual pharmaceutical drugs, have been replaced by NPNs or Natural Product Numbers. (Homeopathy gets its own special number called a DIN-HM for “Homeopathic Medicines,” which is an egregious abuse of the word “medicine,” in my opinion.)

An NHP is defined as a naturally occurring substance that is used to restore or maintain good health. It includes plants, algae, bacteria, fungi, animal material or any extract or isolate of the above, as well as vitamins, amino acids, essential fatty acids, minerals, and probiotics, but also everyday consumer products like shampoo, antiperspirant, and toothpaste. The category does exclude anything that has to be administered by puncturing the skin, as well as cannabis and related products (except for hemp).

When it comes to making health claims, those who want to sell NHPs have two pathways: they can make a modern health claim or a traditional health claim, which is where we slide into dodgy territory. A modern health claim must be backed by studies done in cells, animals or humans, or on textbooks, pharmacopoeias, peer-reviewed articles or regulatory authority reports. Traditional claims, however, come with much looser justifications. A seller must show “a long history of use,” which can include such whoppers as “used in the time of King Edward II to alleviate coughs” (an actual example provided by Health Canada). There are restrictions on when a traditional health claim can be made—for example, you can’t sell an NHP to treat hyperlipidemia if you are relying on an “ancient practice of medicine” that would not have known what hyperlipidemia was—and risk is taken into consideration when Health Canada looks at an application, but general claims for traditional products only need to be substantiated by providing two independent references, much like applying for a passport for the first time.

O say can you see

In the land of the free, dietary supplements are a perpetual Wild West thanks to lobbyists. Congress was considering increasing the regulation of supplement labelling in the early 1990s. A campaign organized by the health food industry led Americans to think the government was about to ban the sale of dietary supplements. Famously, Mel Gibson starred in an ad in which a SWAT team descended on his house in the middle of the night to prevent him from taking his vitamins. The pressure tactics worked, with President Bill Clinton signing into law the Dietary Supplement Health and Education Act of 1994 (or DSHEA for short), which views supplements as food and puts the burden of proof on the FDA to show that a supplement is unsafe, not on the person selling it to prove its safety… unless the ingredient it contains was introduced since the passing of DSHEA, in which case a justification for why the ingredient is thought to be safe must be presented to the FDA.

Similarly to NHPs in Canada, dietary supplements are defined as vitamins, minerals, herbs or other botanicals, amino acids, or dietary substances for use by humans to supplement the diet, and they can include a concentrate, metabolite, constituent, extract or combination of any of the above, as long as it is to be taken by mouth.

Supplements must be prominently labelled with this warning following a listed claim: “This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.” In skeptical circles, this is colloquially known as the “quack Miranda warning,” loosely modeled on the fact that a person being arrested in the United States must be read their rights before their statements are allowed to be used against them. Here, the label disclaimer warns the consumer that any claim made by the seller of the supplement may not be used against them in a court of law. The phrase was coined by an internist who blogs under the name PalMD and who wrote the following incisive comment: “When I treat someone for a medical problem, I pretty much say that I intend to diagnose, treat, cure, or prevent a disease. Why would I say otherwise? It would be a lie.”

Dietary supplements cannot make health claims (e.g. treats asthma), but they are allowed to make what are called “structure/function claims” (e.g. maintains healthy lung function). These statements are about the role a dietary ingredient plays in the normal structures and functions of the human body, like how calcium builds strong bones and how fibre helps maintain digestive regularity. These claims are not preapproved by the FDA.

When it comes to regulating the marketing of dietary supplements, the FDA and the Federal Trade Commission (FTC) work together in an attempt to ensure said marketing is truthful and not misleading. The FDA is primarily responsible for product labels; the FTC, for advertising. A long document by the FTC explaining what is not allowable in the marketing of dietary supplements may provide reassurance that consumers are in good hands, but the reality is that, on either side of the border, we are sold insidious claims, debunked traditions, and adulterated products.

Regulatory failures

In 2015, the consumer protection show CBC Marketplace broadcast an episode in which journalist Erica Johnson and her team created a fake homeopathic children’s remedy and got a product license from Health Canada. To prove its safety and effectiveness, all they had to do was attach photocopies from an old homeopathy encyclopedia, which recommended phosphate of iron and phosphate of magnesia for fever and pain (as well as a long list of conditions including colic, frostbite, and prolapse of the anus). With egg on its face on national television, the government agency made the narrowest possible modification to its regulation of homeopathic NHPs: those sold for cough, cold and flu and aimed at children can no longer make specific claims unless backed by science. Change, however, has been lethargic on store shelves.

In trying to keep everyone happy, regulatory agencies have ended up more or less endorsing practices that predate science and have no connection to human biology. In choosing the right NHP, Health Canada encourages people to seek the advice of a healthcare professional, and they include in that list naturopaths, whose belief system includes such nonsense as homeopathy. In fact, I found eight different licenses, many still active, that Health Canada gave to homeopathic X-rays, in which alcohol is exposed to X-rays, diluted multiple times, and dropped on a sugar pellet. The indication? Itching or skin rash aggravated at night and in bed. Quaint words like “claptrap” and “gobbledygook” were created exactly for a situation like this.

I was also dismayed to find the phrase “relief of Qi stagnation” in a now-archived Health Canada document, not as a dismissal of a claim that cannot be true but as an example worthy of discussion. The document explains that in traditional Chinese medicine—a system which was assembled from disparate traditions by Mao Zedong in the mid-20th century even though he did not believe in any of it—ingredients can be king, minister, assistant, or messenger. Health Canada writes that, within a specific Chinese health product that mixes in many ingredients, the crow-dipper plant “is considered to be a king medicine ingredient as it addresses the main pattern of disharmony (i.e. dampness-phlegm).” This respect for prescientific thinking does not, bizarrely enough, extend to Europe’s four humours theory, in which illness was thought to be caused by an imbalance in black bile, phlegm, yellow bile, and blood. The problem of endorsing pseudoscientific theories of healing unfortunately goes all the way up to the World Health Organization and is unlikely to be solved anytime soon.

While NHPs must be licensed through Health Canada, dietary supplements do not go through the FDA. That agency’s first priority is to public health emergencies and to products that may have caused illness or injury. It then dedicates resources to investigating products thought to be in violation of the law. Only after finishing this work can it conduct routine monitoring of supplements. Dietary supplements represent a massive and lucrative industry: the number of dietary supplements being sold in the US has expanded almost 20 times since 1994. Regulatory agencies simply do not have the means to keep a close eye on this market, which means that adulterations and contaminations are not infrequent. An expensive plant can be swapped for a cheaper lookalike, which means you don’t really know what you’re getting when buying these natural health remedies. The medical literature contains many reports of allergic reactions, chronic diarrhea, and liver damage caused by herbal products incorrectly labelled, and imperfect analyses have reported that a little over a quarter of herbal products worldwide are adulterated.

Regulatory agencies seem to be caught between two chairs: they must protect the public from harm while allowing the national economy to benefit from the sale of products which medical professionals and scientists have decried as useless. A few of these supplements have proven their worth, such as folic acid during pregnancy. Others, like vitamin D supplements in the winter months for people living in colder climes, are still the subject of vigorous debate. And supplements can rescue someone from a medically diagnosed deficiency. But most of these natural health products and dietary supplements are simply not needed, and the structure/function claims allowed to be made for them can make consumers believe they will treat their health condition. If you are feeling sick and shop around for an immune booster (which is a problem, as the whole concept of boosting your immune system is misunderstood), you will see plenty of supplements claiming they will “support immune health.” Why wouldn’t you think they will help treat your infection? Technically, that is not what they are claiming, but to the average consumer learning the difference, it will feel like legal wordplay.

The very fact that the Government of Canada slaps an official designation on these products, an NPN or DIN-HM, is a benediction of sorts. It can be perceived as a gauge of safety and effectiveness. The converse, where the American government does not license these supplements at all, opens the door for a thriving market where anything goes and consumers are left adrift. Damned if you do, damned if you don’t. The Canadian system would be better, in my opinion, if it prohibited traditional claims and demanded high-level scientific evidence. Effectiveness does not manifest simply because of ancestral beliefs. It must be demonstrated through rigour. The industry would cry foul, but consumers’ health and wallet would be better protected.

Note: If you believe a dietary supplement is making claims beyond the soft “structure/function” claims allowed, you can report it to the FTC by clicking here. You can also report an illness or serious allergic reaction after taking a dietary supplement by filing a report here. In Canada, you can submit a complaint form for a natural health product (including homeopathy) here. As of June 22, 2023, Health Canada can now order a recall of an NHP that presents a serious or imminent risk of injury to human health. Prior to this date, the agency did not even have that power.

Take-home message:
- In Canada, natural health products must be licensed by Health Canada and must make a health claim, although traditional health claims are allowed and do not require scientific evidence
- In the United States, the Food and Drug Administration is not allowed to approve dietary supplements and cannot keep track of what is being sold
- Both systems have allowed the sale of supplements that do not have good evidence for effectiveness and that are often adulterated or contaminated


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