Most of us are fortunate to live in countries where we don’t have to worry about counterfeit drugs. We can be confident that the prescription we receive, or the drugs we purchase from the pharmacy, are of high quality and contain exactly what’s on the label. But in these same countries, there’s another group of products where the risks of counterfeits are very real – it’s among the dietary supplements that are often found on the same shelves. Dietary supplements are not regulated in the same way as drug products. The American supplement industry is a multi-billion dollar free-for-all with little meaningful safety or quality regulation. Supplement quality and safety issues are in the media regularly as a result. The most recent example comes from the New York State attorney general’s office. It has accused four large retailers of selling supplements that failed to contain labelled ingredients. Testing the products with a technology called “DNA barcoding”, the AG’s office concluded that most of the products contained little to none of the labelled ingredient. And they also found ingredients that were not disclosed on the label. The AG’s office has demanded these products be removed from store shelves, and the stores stand accused of fraud.
It’s rare that I recommend dietary supplements. I have no particular bias against supplements, but I follow the evidence. A supplement worth taking is backed by good evidence, and is unlikely to cause harm. Most supplements fail this test – usually because they lack good evidence to show they work. But even where the evidence is promising (and the risks appear acceptable), there’s an additional consideration with dietary supplements – supplement quality is unclear. And there’s no easy way for a health professional or a consumer to independently verify that a product is of high quality. Regulatory structures leave a lot to be desired, resulting in a “buyer beware” marketplace for consumers.
Both users and critics of dietary supplements should all agree that these products need to be manufactured to high quality standards. We need regulation from a consumer protection perspective, if only to ensure we’re getting what we’re paying for. Weak regulation that doesn’t require manufacturers to demonstrate quality before products are sold, or fails to hold manufacturers to account when things go wrong, might be expected to result in products that satisfy a low standard. And that’s the reality with supplements today.
The term “supplement” describes a wide array of products. Many are herbs or other plant materials. As I’ve written before, a surprising number of drugs are based on natural ingredients. Acetylsalicylic acid (aspirin) is derived from salicin found in the bark of the willow tree. The antimalarial quinine is found in the bark of the Cinchona tree. The benefit of drugs over herbs is that their effects are more predictable and reliable: the active ingredient is identified, isolated, and then manufactured in a dosage form that can be absorbed by the body. The same can’t be said for products sold in their raw form, as herbs. Herbs are essentially unpurified drugs. One herb may have several different active chemical ingredients, several of which may have medicinal effects. The content in the plant sample may vary based on factors like growing conditions, harvesting conditions, and what portion is consumed. Some herbal products do “standardize” and verify one or more chemical constituents, where the active ingredient is measured, but this is rare. Without standardization, we have no idea if a herbal product contains some – or any – purported active ingredient. We may have the right species of plant, but we have no easy way to verify it contains the right amounts of the right active ingredients necessary to create some sort of effect.
So what did the New York attorney general find? In four of five cases, the herb wasn’t even found in the sample. The AG used the same DNA barcoding technology that I have described before. In this most recent study, the following were tested, with dismal results:
GNC (Herbal Plus brand):
- Gingko biloba: None found, detected garlic, rice, spruce, asparagus
- St. John’s wort: None found, detected garlic, rice, and dracaena (a houseplant)
- Ginseng: None found, detected rice, dracaena, pine, wheat, grass and citrus
- Echinacea: None found, detected rice
- Saw palmetto: One sample had the product
- Garlic: Contained garlic!
Target (Up and Up brand)
- Gingko biloba: None found, detected rice, garlic and mung bean
- St. John’s wort: None found, detected garlic, rice and dracaena
- Garlic: Contained garlic! (one test detected no product)
- Echinacea: Found in most samples
- Saw palmetto: Found in most but not all samples
- Valerian: None detected, found allium, bean, asparagus, pea family, rice, wild carrot and saw palmetto
Walgreens (Finest Nutrition brand)
- Gingko biloba: None found, detected rice
- St. John’s wort: None found, detected garlic, rice and dracaena
- Ginseng: None found, detected garlic and rice
- Garlic: None found, detected palm, dracaena, wheat and rice
- Echinacea: None found, detected garlic, rice and daisy
- Saw palmetto: contained saw palmetto!
Walmart (Spring Valley brand)
- Gingko biloba: None found, detected rice, dracaena, mustard, wheat, radish
- St. John’s wort: None found, detected garlic, rice and cassava
- Ginseng: None found, detected rice, dracaena, pine, wheat/grass and citrus
- Garlic: One sample had product
- Echinacea: None found
- Saw palmetto: Some samples contained small amounts. Also found garlic and rice
This sounds another slam dunk for prosecutors and represents the worst possible scenario: fraudulent marketing and shoddy manufacturing with ingredients missing, and other ingredients included, but not disclosed. It’s simply not possible to use supplements safely under these circumstances. But there’s been an interesting twist: One manufacturer and other critics are challenging the AG’s methodology, claiming that DNA barcoding is inappropriate and insufficient to detect ingredients. They stated that the DNA may not survive processing, but that doesn’t mean the original product isn’t there. They also claim that the “contaminants” may be acceptable fillers. But this doesn’t explain the fact that some tests found product, and others didn’t – even within the same brand. The AG, in response, is pointing to data suggesting that this methodology has been validated. Given the testing was done by a private organization and is unpublished, there’s insufficient information to say. However, even critics of the supplement industry that have looked at the AG’s analysis agree that DNA bardcoding, by itself, may be insufficient. Without more data, and the assessment of experts, it’s impossible to draw firm conclusions. The root cause here is that there is no evidence these products have any medicinal effects. Without proof they do anything medicinal, we can’t identify any specific active ingredient, nor can we test for it. DNA barcoding can’t do any of this – it can only identify if the raw (source) material is present. And that alone may be insufficient.
David Kroll, writing in Forbes today, describes another problem we often find with supplements: adulterants. He describes the case of INSANE bee pollen and EDGE Amplified Weight Loss, both of which have been spiked with the antidepressant drug fluoxetine (Prozac). Kroll points out the product label claims these supplements meet Good Manufacturing Practice (GMP) standards, a laughable claim given the findings. This finding in the supplement industry is not uncommon. The FDA posts all recalls and you’re regularly find products marketed as supplements that are recalled for containing undeclared drugs. This month (so far) the FDA has issued new warnings for Reumofan Plus and Maxiloss Weight Advanced. It’s important to note that DNA barcoding alone won’t detect drug adulterants, owing to the lack of DNA.
Without reliable, consistent supplements, consumers don’t get what they pay for, and health professionals can’t advise on their safe use. Given the limited evidence of efficacy for supplements, and the repeated concerns about product quality, I continue to advise that consumers approach supplements with great caution. The potential benefits need to be pretty compelling to justify their use. There’s a lack of good evidence to suggest most supplements offer any meaningful health benefits. While the supplement market continues to grow, it’s becoming harder to identify products that are truly safe and effective. We need better regulation and product quality standards to ensure the consumers that purchase supplements can do so with confidence, and use them safely.
Photo from flickr user Superfantastic used under a CC licence.