Dietary supplements – less regulated than dog food

In case you didn’t already guess from the title, one thing that really gets me going is when people or companies claim that a dietary supplement or alternative therapy is ‘safe’ because it’s ‘natural.’  Not only can dietary supplements be ineffective, but they could actually be harmful.  The problem is that these compounds are not regulated by any oversight agency in the United States.  Any yahoo can bottle an herb and write pretty much whatever they want on that bottle’s label.  A recent article published in Nature got me going on this topic.  Titled Buyer Beware, the article ran through a case-study of the so-called anti-ageing miracle drug, reservatrol.  It started when some well-meaning researchers published preliminary results that reservatrol (isolated from grape skins) may improve and extend the lives of some lab animals.  Since we’re all looking for the fountain of youth, the media ran with it.  A decade later, the true effects of reservatrol on lifespan and other health issues is still not certain and its role in the complex aging process is not understood.  But this didn’t stop unscrupulous individuals and companies from leaping on this opportunity to market a new anti-aging miracle.  To make it worse, the FDA (the agency that regulates drug manufacturers to (usually) make sure their products are safe and effective) is under congressional mandate to NOT regulate the dietary supplement/vitamin industry.  In a perfect example of strategic naming of a bill to hide its true purpose (see the PATRIOT act), the Dietary Supplement Health and Education Act of 1994 actually prevented the FDA from regulating the dietary supplement/vitamin industry.  So that means not only can companies market products with false/unproven claims, there is no watchdog there making sure these same products are even safe. Compounding this lack of regulation is many people’s beliefs that just because something is natural, it is safe.  Nothing could be further from the truth: how many poisonous plants, bugs, or snakes can you think of?  These critters are as natural as it gets, but very harmful to your health (at least if you eat, touch, or are bitten by them).  Add lead, mercury, or radon to the list (all naturally occurring elements), and we know that nature can really mess us up.  So, if your bottle of pills says that’s it’s ‘All Natural,’ not only may you be eating something dangerous, there is no watchdog agency making sure what you’re eating is safe.  In the US, dogfood is much more carefully regulated than vitamins.

Now, I’m not saying that there isn’t a place for natural remedies in health care.  A lot of important medicines have come from traditional medicine.  For example, many antibiotics and a new anti-malarial treatment all came from bacteria or plants that were used in traditional medicine.  The thing that separates many of these compounds from the snake-oil is that they have been well evaluated in controlled trials for both efficacy and safety.  This is not true for the majority of dietary supplements.  I’m also not saying that many new therapies will not come from traditional medicine, be extracted from plants, or found otherwise in nature, or that some people don’t get relief from specific dietary supplements.  All of this is possible and likely.  I just can’t believe that companies can get away with making such outrageous claims without any scientific evidence to support them.

Here is a small sampling of million/billion dollar supplements that lack solid evidence to support their use in health care:

Glucosamine/Chondroitin for treatment of arthritis:
This is actually a billion dollar industry, despite the fact that two in-depth long term clinical trials that evaluated glucosamine/chondroitin for treatment of arthritis found little to no benefit. The Glucosamine/Chondroitin Arthritis Intervention Trial (GAIT) was a  large, randomized, placebo-controlled trial (the gold-standard for clinical trials) funded by the National Center for Complementary and Alternative Medicine (NCCAM) and the National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMSD).  The trial evaluated two important things: if glucosamine and/or chondroitin relieved pain associated with arthritis of the knee, and if glucosamine and/or chondroitin diminished the structural damage caused by arthritis.  Even though these results were published as early as 2006, these compounds are still marketing as relieving arthritis, despite evidence to the contrary.  While there was some positive effect on people suffering from severe pain, this effect was not observed in the larger patient population with a range of pain.  What was suprising in this study was how effect a placebo was in relieving pain (see press releaseoriginal paper).  The study also showed no improvement in loss of cartilage when patients used glucosamin, chondroitin, or both.  Again, a simple placebo should a surprising positive effect over no treatment, so much of the hyp around glucosamine/chondroitin may be due to the placebo effect (see press release, original paper)

Echinacea for treatment of colds: A randomized, double-blind, placebo-controlled trial to assess the efficacy of dried, encapsulated, whole-plant echinacea as an early treatment for the common cold showed no difference between echinacea and placebo in severity or duration of the common cold (Treatment of the common cold with unrefined echinacea. A randomized, double-blind, placebo-controlled trial.).  Similar results were found in a clinical trial conducted in children (Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial).  It could be that the preparation of echinacea in these trials wasn’t optimal, but right now I’m waiting for proof that some specific use of a specific extract or type of echinacea is beneficial before I run to the health food store next time I get the sniffles.

St John’s Wort for treating depression: I think how the NCCAM summarizes the research around efficacy of St John’s Wort epitomizes the inherent problem with dietary supplements.  There are conflicting results.  The thing that makes me lean more towards thinking that St John’s Wort is snake oil is that in the randomized, blinded, placebo controlled trials, no effect was observed.  It’s easy to read results in to a study that doesn’t have the proper controls.  It’s also possible that St John’s Wort can be harmful as it could have negative interactions with many commonly prescribed pharmaceuticals.  (Effect of Hypericum perforatum (St John’s wort) in major depressive disorder: a randomized controlled trial) In a double-blind, randomized, placebo-controlled trial, St John’s Wort did not show any improvement for people with moderately severe major depression.

Black Cohosh to relieve PMS: Unfortunately (for me) it looks like most of the research on this herb are done in Germany, so I can’t read the papers (published in German).  I’m relying on the NCCAM, the NIH Office of Dietary Supplements, and the US Pharmacopeia websites to summarize findings.  While there are some concerns that this herb may cause liver toxicity (United States Pharmacopeia review of the black cohosh case reports of hepatotoxicit ), a randomized, double-blind, placebo-controlled trial showed no reduction of hot flashes in breast cancer survivors.  (see Office of Dietary Supplements for research reviews).  Another randomized, double-blind, placebo-controlled trial of 80 post-menopausal women (a pretty small sample size) did show some improvements when Black Cohosh was compared to conjugated estrogen.  Other non-placebo controlled trials (which throws the results in to doubt when there isn’t a gold-standard for treatment that already exists) showed mixed results as well.

Ephedra for weight loss: Calls to poison control centers and other systematic reviews have linked the use of ephedra to heart problems and stroke, but since this isn’t a ‘drug’ which has been run through clinical trials, even proof of side-effects can be difficult.  While the FDA did manage to ban dietary supplements that contained ephedra, in a prime example of how FDA oversight of traditional medicine is lacking, traditional herbal remedies or herbal teas that contain ephedra are not banned.  I don’t really understand the distinction here between dietary supplements and traditional herbal medicines, and worry about the 37 reports of heart attack, stroke, and sudden death that have been implicated with use of ephedra.

Many people may experience health benefits from taking vitamins, herbal or dietary supplements, or alternative therapies.  I don’t mean to judge their choices.  I just hope they know that the health claims that are made about these compounds haven’t been proven, and that the safety of these ‘medicines’ hasn’t been proven.

Good source of scientific information: The National Center for Complementary and Alternative Medicine (a branch of the US National Institutes of Health)