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The False Allure of “Natural” Treatments And The Lessons Learned From Foxglove

A patient asked me to read a print out of the information contained in the “Life Extension magazine” July 2007 issue entitled “Reversing Atherosclerosis Naturally” because I had recommended statin (cholesterol lowering) medical therapy to her and she did not want to take statins but preferred a “natural” way to address her problem of advanced atherosclerosis.

After looking at the document she presented me, I concluded that Life Extension’s only goal is to convince naive searchers for “natural” methods of treating or preventing heart disease and aging that they should be taking one of many unproven “plant-derived” supplements sold on the site. (This, of course, is one of the red flags of quackery.)

The “article” begins with the following exciting pronouncement:

“Scientists have discovered a natural ingredient derived from a species of melon that has been shown to reverse signs of atherosclerosis in aging blood vessel walls. This nutritional supplement is able to boost levels of the body’s most powerful antioxidant defense enzyme, superoxide dismutase (SOD)”

The first sentence should be the tip-off for the reader that this is a site selling useless, unregulated yet expensive “nutraceuticals.” I could spend a thousand words (and minutes) convincing you that this supplement is useless but it is only one of hundreds of similar preparations, so my time would be wasted. Instead, let’s look at the problem in general.

The Allure of “Natural” Treatments

What attracts patients to use substances that are sold over the internet without any guarantee that they are effective, safe or that they even contain the “active” ingredients the promoters claim?

I really like Anthony Almdada’s description in his chapter in Nutraceutical And Functional Food Regulations In The US.

“The quest for “natural,” the drive to engage in “self-care” and the almost free and boundless access to the virtual, omniscient libraries called the Internet and social media messaging are forging a new breed of companies and consumers. Armed and dangerous with a modicum of evidence of simply a sugar-coated science tale, bioactives are birthed, brands are born, products are launched.”

Steven Novella (Science-Based Medicine) has written eloquently about the “plant vs pharmaceutical false dichotomy” here. He quotes the (Dr Oz featured) “Medicine Hunter,” Chris Kilham, as saying:

“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”

Kilham has created a forced choice or false dichotomy which would lead one to choose herbs over pharmaceuticals. In reality, the pharmaceutical drugs are the substances which have been proven safe and effective (having undergone rigorous trials in humans and an intense review process by the FDA) despite being manufactured by man. Herbs and nutraceuticals, despite coming from nature, are not proven to be either safe or effective.

Novella writes:

“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.”

What Happens to a Plant-derived Substance That Proves Safe and Effective for a Medical Condition?

The simple answer is that it moves from the unregulated, over the counter, internet-marketed realm into the realm of being regulated by the FDA and prescribed by doctors.

A really great example of a botanical that became a useful pharmaceutical is digoxin.

Two hundred and fifty years ago, doctors had no FDA to help them choose safe and effective medications. They tried various, presumably medicinal, botanical preparations on their patients to see what worked.

Sometimes the patient got better, sometimes not.

Sometimes the patient got violently ill and died.

Since the doctors were only working on one patient at a time and did not have the luxury of large randomized trials to guide them, they could only guess whether the substance they had given their patient helped or hurt.

Through the wonders of the internet, you can download for free and read for yourself the experiences of one such doctor, William Withering, who was experimenting on his patients with a preparation made from the leaves of a plant with the Latin name of digitalis purpurea, more commonly known as foxglove.

I have waxed poetic innumerable times (see here and here and here) on the glorious, mystical and medicinal foxglove plant.

Foxglove from the skeptical cardiologist’s medicinal garden. I don’t treat my patients with this and it will kill bunnies.

Withering tried different ways of preparing it, sometimes using an infusion, sometimes a powder, and he tried different amounts on his patients. He recognized that the concentration of the active ingredient in the plant was different depending on the time of year, the growing conditions, and the part of the plant he utilized. There was no standardization of concentration available to him.

The only way he knew that he had given too much was when the patient’s pulse slowed too much, the patient vomited or the patient died.

Over time, chemists and physiologists were able to identify the active chemical in foxglove, now called digitalis or digoxin, and produce it in a form that was pure and consistent.

According to GlaxoSmithKline, farmers in the Netherlands grow fields of woolly foxglove, which is a member of the snapdragon family. Bales of dried foxglove leaves are shipped to the U.S. Here, processing facilities macerate the leaves and extract digitalis using an aqueous-alcohol solvent. Further treatment and processing yields powdered digoxin, which is compounded into tablets, injectable solutions, elixirs, and capsules. It takes about 1,000 kg of dried foxglove leaves to make 1 kg of pure digoxin, the company adds.

Cardiologists are still using digoxin, primarily to slow the heart rate in patients with atrial fibrillation and to a lesser extent, to help patients with congestive heart failure.
We use less of it than we did 50 years ago because of the development of synthetic drugs, which are more effective for these conditions.

In addition, digoxin has what we term a narrow therapeutic window; even when we use precisely formulated pills and monitor levels  we can sometimes run into the problems from side effects that William Withering saw 250 years ago using foxglove leaves: slow pulse, vomiting and life-threatening abnormal heart rhythms.

With the development of safer precisely formulated drugs (like beta-blockers) there is virtually no need for digoxin. Indeed, as I pointed out here and here, recent studies showing increased mortality in patients on digoxin should signal the death knell for foxglove as a therapeutic agent (although I am still growing it in my garden.)

To my patients who are attracted to internet-marketed, non FDA-regulated “natural” cures for aging and atherosclerosis I say: Take these substances at your own risk, they have been proven neither safe nor effective.

Although it is wise to be cynical and skeptical of drugs that are researched and heavily marketed by big pharmaceutical companies, at least we have the reassurance that they have all gone through a rigorous process of testing for both safety and efficacy, and that the pills we put in our mouths contain a precise amount of the active ingredient without any contaminants or unknown ingredients.

Skeptically Yours,


N.B. Most of this was written 4 years ago but I was stimulated to republish it for 3 reasons: 1) I’m still using digoxin in very select patients 2) A recent study suggested digoxin was not inferior to beta-blockers for controlling heart rate in atrial fibrillation

and 3) Robert Turner , at Medium’s Being Well wrote this which I’m pretty sure was stimulated by an email I sent him:

Medika has recently launched an apothecary section, in which we intend to examine herbs and plants and the medicinal properties associated with these plants. We believe this natural reservoir offers a largely untapped source of treatment options for a host of medical conditions. The value of many of these natural compounds is only now beginning to enjoy serious attention.

I was shocked when a medical colleague questioned the inclusion of these articles in our publication, suggesting they are baseless and pseudoscience. The exact term used was “wooo”. Sadly, this opinion is shared by many colleagues and the alternative health sector is largely to blame for this perception. It has led to a widening chasm between modern medicine and traditional medicine, which is now seen as the home of modern-day witches, spiritualists, and charlatans.

The article on Medium’s Being Well that I questioned was entitled “Brew Sacred Cedar Tea And Reap Powerful Health Benefits”. The author cites numerous potential health benefits without any scientific support. She recommends brewing your own cedar tea and then warns of potential toxicity if one consumes more than a cup per day.

Sourcing cedar is as easy as stepping outside your doorstep. Discover the remarkable health properties of this ordinary tree.

The author ends with a personal testimonial

From the first moment I touched my lips to the mug and drank in the rich aroma of cedar, I fell in love. The stronger, the better. I can almost visualize the health benefits occurring in my organs and cellular level.

This is a perfect example of dangerous woo: a baseless claim for a “natural” substance which has unproven benefits and potential toxicity. At least foxglove has proven benefits to go with its toxicity but I would never advise afib patients to brew a tea from it.

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