Better Health: Smart Health Commentary Better Health (TM): smart health commentary

Article Comments (1)

Herbalists: If Ancient Wisdom Exists, So Does Ancient Stupidity

David Kroll’s recent article on thunder god vine is a great example of what can be learned by using science to study plants identified by herbalists as therapeutic. The herbalists’ arsenal can be a rich source of potential knowledge. But Kroll’s article is also a reminder that blindly trusting herbalists’ recommendations for treatment can be risky.

Herbal medicine has always fascinated me. How did early humans determine which plants worked? They had no record-keeping, no scientific methods, only trial and error and word of mouth. How many intrepid investigators poisoned themselves and died in the quest? Imagine yourself in the jungle: which plants would you be willing to try? How would you decide whether to use the leaf or the root? How would you decide whether to chew the raw leaf or brew an infusion? It is truly remarkable that our forbears were able to identify useful natural medicines and pass the knowledge down to us.

It is equally remarkable that modern humans with all the advantages of science are willing to put useless and potentially dangerous plant products into their bodies based on nothing better than prescientific hearsay.

Ancient Sumerians used willow, a salicylate-rich plant that foreshadowed modern aspirin. Digitalis was used by the ancient Romans long before William Withering wrote about its use for heart failure. South American natives discovered that chinchona bark, a source of quinine, was an effective treatment for malaria. These early herbal remedies pointed the way to modern pharmaceuticals. How many other early remedies fell by the wayside? What else did the Sumerians, the Romans, and the natives use that did more harm than good? If “ancient wisdom” exists, so does “ancient stupidity.”

Plants undeniably produce lots of good stuff. Today researchers are finding useful medicines in plants that have no tradition of use. Taxol, the cancer-fighting product of Pacific yew trees, was discovered by the National Cancer Institute only by screening compounds from thousands of plants.

There is a reason pharmacology abandoned whole plant extracts in favor of isolated active ingredients. The amount of active ingredient in a plant can vary with factors like the variety, the geographic location, the weather, the season, the time of harvest, soil conditions, storage conditions, and the method of preparation. Foxglove contains a mixture of digitalis-type active ingredients but it is difficult to control the dosage. The therapeutic dose of digitalis is very close to the toxic dose. Pharmacologists succeeded in preparing a synthetic version: now the dosage can be controlled, the blood levels can be measured, and an antibody is even available to reverse the drug’s effects if needed.

“Ancient wisdom” argues that if an herbal remedy has been used for centuries, it must be both effective and safe. That’s a fallacy. Bloodletting was used for centuries but it wasn’t effective and it did more harm than good. If a serious side effect occurred in one in a thousand recipients of an herb, or even one in a hundred, no individual herbalist would be likely to detect it. If a patient died, they would be more likely to attribute the cause to other factors than to herbs that they believed were safe. Even with prescription drugs, widespread use regularly uncovers problems that were not detected with pre-marketing studies.

Arguments in favor of herbal remedies include:

  • They’re natural. (So what? Strychnine is natural.)
  • They’re safer than prescription drugs. (Maybe some are, some aren’t; how would you know?)
  • They’re milder than prescription drugs. (That would depend on the dosage of active ingredient.)
  • They’re less likely to cause side effects. (When they have been as well studied as prescription drugs, they may turn out to have just as many or more side effects. All effective drugs have side effects, and if an herbal medicine has fewer side effects it might have fewer therapeutic effects too. Formal systems for reporting adverse effects have long been in place for prescription drugs; not so for herbal remedies.)
  • They’re different from prescription drugs. (Some are identical to prescription drugs, like red yeast rice which contains the same ingredient as prescription lovastatin; and some herbal products have been found contaminated with prescription drugs.)
  • They’re less expensive. (True, but is a cheaper, inferior product a good bargain?)
  • They’re easier to obtain. (True, you don’t have to make an appointment with a doctor; but that means you don’t get the benefit of a doctor’s knowledge.)
  • The mixture of ingredients in a plant can have synergistic effects. (This is widely claimed but almost never substantiated. The other ingredients are just as likely to counteract the desired effect or to cause unwanted adverse effects.)
  • For every disease, God has provided a natural remedy. (Perhaps this is a comforting thought for believers, but it is not based on any evidence and is not convincing to atheists and agnostics. And it doesn’t help us find that natural remedy.)

Even when an herbal remedy works, finding a safe and reliable source is problematic. Horror stories abound:

  • Contaminants (such as heavy metals, pesticides, carcinogens, toxic herbs, and insect parts).
  • Wild variation in content (from no active ingredient to many times the amount on the label).
  • Mislabeled products that contain an entirely different herb.

I won’t list specific examples here; they are easy enough to find. I’ll just say that natural medicines are not regulated the way prescription drugs are, thanks to the infamous Diet Supplement and Health Education Act (DSHEA) of 1994.

When you take an herbal remedy, you are taking

  1. An active ingredient that usually has not been adequately tested,
  2. Other components that have not even been identified, much less tested,
  3. An uncertain amount, and
  4. Possible contaminants.

The term “street drugs” comes to mind: you don’t really know what you’re getting.

*This blog post was originally published at Science-Based Medicine*


You may also like these posts

Read comments »


One Response to “Herbalists: If Ancient Wisdom Exists, So Does Ancient Stupidity”

  1. Health Blog says:

    Herbal medicines fascinate everybody and there is a misconception that herbal medicines have no side effects, which is totally wrong. Herbal drugs like any other drugs have potential benefits as well as they can harm too.

Return to article »

Latest Interviews

Caring For Winter Olympians In Sochi: An Interview With Team USA’s Chief Medical Officer Dr. Gloria Beim

I am a huge fan of the winter Olympics partly because I grew up in Canada where most kids can ski and skate before they can run and partly because I used to participate in Downhill ski racing. Now that I m a rehab physician with a reconstructed knee I…

Read more »

How Do Hospital Executives Feel About Locum Tenens Agencies And Traveling Physicians?

I recently wrote about my experiences as a traveling physician and how to navigate locum tenens work. Today I want to talk about the client in this case hospital side of the equation. I ve had the chance to speak with several executives some were physicians themselves about the overall…

Read more »

See all interviews »

Latest Cartoon

See all cartoons »

Latest Book Reviews

The Spirit Of The Place: Samuel Shem’s New Book May Depress You

When I was in medical school I read Samuel Shem s House Of God as a right of passage. At the time I found it to be a cynical yet eerily accurate portrayal of the underbelly of academic medicine. I gained comfort from its gallows humor and it made me…

Read more »

Eat To Save Your Life: Another Half-True Diet Book

I am hesitant to review diet books because they are so often a tangled mess of fact and fiction. Teasing out their truth from falsehood is about as exhausting as delousing a long-haired elementary school student. However after being approached by the authors’ PR agency with the promise of a…

Read more »

Unaccountable: A Book About The Underbelly Of Hospital Care

I met Dr. Marty Makary over lunch at Founding Farmers restaurant in DC about three years ago. We had an animated conversation about hospital safety the potential contribution of checklists to reducing medical errors and his upcoming book about the need for more transparency in the healthcare system. Marty was…

Read more »

See all book reviews »