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Why Natural Supplements Are Not a Safe Bet
Natural supplements are often ineffective and may be harmful.
As someone raised by hippie parents, who grew up on earthy vegetarian fare, and fresh air, I may seem like an unlikely person to be ranting about the dangers of natural supplements. I still love lentil soup and long walks in the forest. But, I’m also a scientist. I understand how drugs and vaccines are discovered, tested, and regulated - and how things are different for natural supplements (vitamins, dietary supplements, nutraceuticals). This is why I get find myself frustrated daily by the unwarranted health halo that comes with a natural label. It’s painfully ironic that the same people who shun “dangerous” drugs eagerly pour money into untested natural products.
A recent study estimated that the US vitamin and supplement market is worth almost 200 billion dollars! Every time I walk past a supplement store, I cringe, thinking of all the people pouring their money and hopes into supplements that fail to deliver - and may even be dangerous. The “natural” label is brilliant marketing - it taps into our intuitive sense that natural products must be good and safe.
Why natural makes sense
To be fair, there is some validity to the belief that natural products are a safe bet. It makes sense to lean into things that have stood the test of time - this principle is well-recognized by health regulators. For example, the US FDA has a designation called GRAS or Generally Recognized As Safe, which exempts a substance from extensive pre-market testing. One path to a GRAS designation is when the substance has a long history of (safe) use in food.
By contrast, novel substances inherently come with some level of risk, because it can sometimes take years for the full risk profile of a substance to become clear. We can mitigate this risk with rigorous testing in labs, animals, and clinical trials, but it can be challenging to tease out rare events, or those that take years to develop (note: this is why regulated drugs and vaccines have ongoing safety monitoring).
While it makes sense to be leery of new things and to feel more comfortable with familiar substances, we can get into trouble when we elevate the term “natural” above all other considerations. I’m writing this post to urge you to take a step back to evaluate whether you’re spending your time and money wisely, on strategies that are safe and effective.
Here are three major problems with putting all your eggs in the natural basket:
Problem #1: Natural substances are not tested for safety or efficacy before being sold. Claims may be invalid.
Before they can be marketed, drugs and vaccines undergo extensive testing to prove that they are safe and that there is strong evidence supporting any health claims. This is not true for natural supplements. For these products, safety and efficacy are policed (sporadically) after they are on the market.
According to the US FDA: “Unlike drugs that must be proven safe and effective for their intended use before marketing, there are no provisions in the law for FDA to approve dietary supplements for safety before they reach the consumer.”
In short, safety is assumed to be fine for natural products - no testing required up front. The safety of a natural product is only questioned if health regulators receive concerning reports of serious adverse events (which may or may not be reported) or happen to find something during an investigation.
Efficacy (does it work?) is a bit of a wild west, too. For natural, dietary supplements, claims about the benefits of a product are not typically reviewed before they are slapped on a package (unlike with drugs and vaccines). That doesn’t mean there aren’t rules. In theory, products should not be labeled with unsupported claims. The FDA does crack down on unsupported health claims when they catch them in the market, but it’s a losing battle of whack-a-mole. Also, it’s easy to finesse the claim language on your package, opting for vague terms, rather than specific disease-related claims that could trigger a violation.
Buying untested, unproven supplements is not just a waste of money and hope. When somebody has a serious medical condition that can be treated with approved medications, there is a major opportunity cost to choosing an unproven alternative approach. A related cost of the natural route is that it can provide a false sense of security that we are covering our bases. It can be tempting to forgo other more challenging - yet impactful - investments (like regular exercise and a high-quality diet) when we are being sold a simple vitamin or supplement that “boosts your immune system”.
Hot tip: Before buying a supplement, check Examine.com for a critical look at the strength of the evidence, or check the scientific literature yourself using PubMed. Look for independent reviews and meta-analyses, because single studies can easily be distorted by funders to make things look rosy.
Problem #2: Quality control is a major issue with natural supplements and compounded drugs.
With regulated drugs (and vaccines) there is extensive regulatory oversight of manufacturing, to ensure purity and dose. This is not the case for natural supplements, and compounded drugs, for which oversight of manufacturing is much lighter than it is for regulated drugs. Technically, the law requires supplement makers to follow “good manufacturing practices”, but violations abound.
This is not just a minor concern that you can swat away like an annoying fly. Dose is everything when it comes to both safety and efficacy of any chemical - natural or not. As they say, “the dose makes the poison” (quote adapted from Paracelsus, the Swiss chemist and physician)! Even a small discrepancy in dose can make a huge difference for some compounds - like hormones. Purity is also paramount for safety. Even trace amounts of contaminants like heavy metals or dangerous microbes can be major health hazards.
Unfortunately, both dose and purity are widely recognized as a major issues in the dietary/ natural supplement and drug compounding industries. Governments are continually working on this challenge, but they simply aren't equipped to tackle the scale of the problem. To get a sense of the massive undertaking required to police violations, check out the database of US FDA warning letters here and here (Compounding: Inspections, Recalls, and other Actions) - and this is no doubt the tip of the iceberg. For a disturbing example, here’s a quote from an FDA warning letter to a vendor of Allergy Bee Gone for Kids nasal swab.
“FDA laboratory testing of a batch of Allergy Bee Gone For Kids Nasal Swab Remedy drug product (lot 2006491) found that it contained objectionable microbial contamination. It was contaminated with bacillus sp., including B. cereus, B. amyloliquefaciens, B. atrophaeus, and others. This contamination is particularly concerning because “Allergy Bee Gone for Kids” is a nasal swab product and directed for use in young children.”
Pro Tip: When buying natural supplements, look for products with third-party-independent testing certification on the label. For example, athletes are now encouraged by the US Anti Doping Agency (USADA) to look for a third-party certification called “NSF Certified for Sport®”.
Problem #3) Natural substances can be a hazard to your health.
Just because something is natural doesn’t mean it’s good for you. This point is obvious but bears repeating. Indeed, many of the most biggest health problems of our time are due to natural substances including alcohol, tobacco, and opioids (both naturally derived and synthetic) - not to mention bacteria and viruses! These are dramatic examples, but the principle applies broadly. Let’s not delude ourselves that something is healthy simply because it’s natural, whether we’re at the pharmacy or the natural foods store.
Similarly, natural products can have side-effects, just like approved medications and vaccines. Unfortunately, these issues are not tested and tracked as rigorously outside of regulated drugs. We know that the risk is real, as some adverse events (but definitely not all) are reported. For example, a study of US adverse event databases found 15, 430 adverse event (safety) reports from January 1, 2004, through December 31, 2013 with a potential link to dietary supplements. Reported serious outcomes included death, life-threatening conditions, hospitalizations, congenital anomalies/birth defects and events requiring interventions to prevent permanent impairments.
Fun fact: Roughly one third of FDA- approved drugs have natural origins! Of these natural products or derivatives, nearly one-half of these are derived from mammals, one-quarter from microbes and one-quarter from plants. See study.
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Whether or not something is natural does not tell you whether or not it’s safe, or good for you. Natural supplements (nutraceuticals and dietary supplements) are often ineffective and may even be harmful, either because of dose, contaminants, or because they lead you to forgo a more effective health strategy.
To me, natural supplements should be used sparingly, when there is a clear need and strong supporting evidence. This is remarkably rare. The best examples are supplements that prevent specific nutrient deficiencies - like calcium and vitamin D.
NB: Multivitamins, one of the biggest sellers, have been repeatedly shown not to offer a clear benefit in the general population (see article from Johns Hopkins).
To make sure you’re spending your money (and effort) wisely, it’s vital to do some independent research both on the product, and the brand, before you buy. An endorsement from a naturopath or sales person at the store does not suffice. Often, you’ll find that the product falls short of the hype. My minimalist approach is clearly not the norm, given the massive size of the supplement industry.
If good health is your goal, the best advice I can offer is to focus on the big picture - the pillars of health that we know are most effective: exercise, healthy diet, sleep, and stress reduction. I see natural supplements as a distraction, an expensive rounding error at best. I invest daily in these health pillars, but also recognize that they cannot make you bulletproof. Sometimes, we need a little help. When I have a medical issue that my core pillars can’t address, I’m far more comfortable taking an approved, regulated medication than a natural supplement. I know that they have been tested in human trials that evaluate both safety and efficacy. I also know that the dose in my prescription is appropriate (and matches the label) and that it’s free of contaminants.
I hope this little rant from a hippie-girl-turned-scientist gives you pause next time you’re tempted to try the latest and greatest supplement. To learn more, please check out the resources below including related podcast episodes. Also, please show me some love by spreading the word!
Wishing you well,
FDA database of warning letters (look for CDER under Issuing Office)
FDA regulations for claims made on foods and dietary supplements.
FDA regulations for drug compounding
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