A recent web feature produced by The New York Times tells the story of Chris Kilham, “The Medicine Hunter.” Specifically it recounts his thoughts on the use of maca, a root native to South America, “said to have energy and libido enhancing properties,” according to the piece. The brief piece reflects the current attitudes popular in the public and promoted by mainstream media reflecting a false dichotomy between medicinal plants and pharmaceuticals. This false dichotomy is extremely counterproductive and ultimately harmful to consumers.

Kilham represents this false dichotomy when he says:

My goal is to have more people using safe, effective, proven, healthful herbs, and fewer people using toxic, overly expensive, marginally effective, potentially lethal pharmaceutical drugs.

There are many unwarranted assumptions in this statement. It seems to be implying that herbs are inherently more safe, less toxic, and more healthful than pharmaceuticals. It also assumes that there is a real difference between the two. Therefore Kilham seems to be saying something meaningful when he is actually just reflecting biased assumptions. This is made clear if we simply reverse his statement. Most people, for example, would agree if I said that “My goal is to have more people using safe, effective, proven, healthful pharmaceuticals, and fewer people using toxic, overly expensive, marginally effective, potentially lethal herbs.”

The most meaningful statement is also the one that is most obvious and hardly needs to be pointed out. Any rational person would rather use safe and effective treatments of any kind than toxic and marginally effective (or ineffective) treatments of any kind. Because everyone is likely to agree with this, Kilham is creating a forced choice in which any rational person would choose herbs over pharmaceuticals. But Kilham’s unstated assumptions are completely unwarranted.

First and foremost, herbs and plants that are used for medicinal purposes are drugs – they are as much drugs as any manufactured pharmaceutical. A drug is any chemical or combination of chemicals that has biological activity within the body above and beyond their purely nutritional value. Herbs have little to no nutritional value, but they do contain various chemicals, some with biological activity. Herbs are drugs. The distinction between herbs and pharmaceuticals is therefore a false dichotomy.

It is critical for effective health care and consumer protection that practitioners, educators, the industry, and regulations focus on that which is important – evidence for safety and effectiveness. Here there is a clear distinction between substances marketed under the regulations for drugs and those under the far looser regulations for herbs and supplements. Drugs typically have far greater evidence for both safety and effectiveness. Herbs, on the other hands, are typically marketed based upon tradition and anecdote with insufficient scientific evidence for safety or efficacy.

So what Kilham should be advocating is for higher and more uniform standards of scientific evidence for all pharmaceuticals, whether they are plant based or not.

Ironically, the focus of the New York Times piece and advocated by Kilham, maca, is almost completely without scientific evidence from human trials. A recent study of maca in humans (the first, as far as I can tell) states, referring to maca:

There are however no published data on their toxicity and safety in humans.

The study, which should be considered preliminary, showed that maca may have some benefits for lipid metabolism. There are a number of studies looking at sperm count in rats showing that maca may increase sperm count, or counteract the effect of high altitude on decreasing sperm count, but this line of research is still in the early stages and has not been replicated in humans.

So Kilham, while stating that he is advocating the use of “proven” herbs, is in fact promoting the use of a plant-derived drug with almost no evidence for safety or effectiveness. This, in my opinion, is what happens when ideology trumps logic and science. Kilham clearly is a strong advocate for the use of botanicals. This appears to have become an ideology that has caused him, and many others, to take their eyes off the ball. The only thing that truly matters is evidence for safety and effectiveness – everything else is a costly and hazardous distraction.

To be fair, I think Kilham has a more nuanced and reasonable position than what was presented on the New York Times piece. In this article by Kilham, for example, he writes:

Some of the criticism aimed at the botanical industry is well founded. For as long as companies borrow science to make marketing claims for their own untested products, the market will be awash with second-rate or wholly ineffective botanicals. Very few companies engage in rigorous science to ensure that their products deliver the health benefits for which they are used. The marketing of untested, ineffective botanicals erodes consumer confidence and leaves the botanical industry wide open to heavy handed regulation.

I completely agree. I think where Kilham and I disagree is in what constitutes good science and adequate evidence for safety and effectiveness. I think he is too soft on botanicals and too harsh on the pharmaceutical industry. This appears to be driven, again, by the ideology of the false dichotomy between plants and “drugs.”

To be clear, I have nothing against plant-derived pharmaceuticals. Plants represent a vast reservoir of biologically interesting chemicals – an evolutionary science lab. I also strongly support efforts to survey the world’s plant life (and animal life, for that matter) looking for potentially useful substances. But in so doing, in order to achieve the maximal benefit for the health of the public, we need to apply adequate and uniform standards of scientific evidence for safety of all pharmacologically active substances, and we should fairly regulate the health claims made for any such products. This means purging ourselves of the sloppy thinking represented by the false dichotomies between natural and synthetic (something which has no bearing on safety or efficacy) and of herbs vs drugs.

There is also, incidentally, a false dichotomy between the pharmaceutical industry and the supplement industry. The two are increasingly merging over time, as the large companies are being drawn to the easy profits of selling supplements without having to pay for expensive clinical trials.

These are myths and fictions perpetrated, unfortunately, by those who would be the strongest advocates for plant-based medicinals – like Kilham, abetted by a mainstream media constrained by established talking points, which includes these fictions. These myths are extremely counterproductive. Once we dispense with them we can most effectively work together toward the common goal of providing the most safe and effective medicinal products to the public, based upon adequate scientific evidence.


Posted by Steven Novella

Founder and currently Executive Editor of Science-Based Medicine Steven Novella, MD is an academic clinical neurologist at the Yale University School of Medicine. He is also the host and producer of the popular weekly science podcast, The Skeptics’ Guide to the Universe, and the author of the NeuroLogicaBlog, a daily blog that covers news and issues in neuroscience, but also general science, scientific skepticism, philosophy of science, critical thinking, and the intersection of science with the media and society. Dr. Novella also has produced two courses with The Great Courses, and published a book on critical thinking - also called The Skeptics Guide to the Universe.