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.


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

  1. There seems to be a lot of psychology behind this false dichotomy and you did a great job of laying out. One facet I think that plays a part in the aversion to taking pharmaceuticals is the false impression that only “sick people” take drugs. I think in general the medical industry is construed as reactionary as opposed to preventative. People go to the doctor when they are sick, not if they are well and people don’t take drugs if they are well, they take them when they are sick. The breakdown happens I think with this thought process, because many drugs like statins for example are preventative compounds that most likely will lower ones chances of actually getting sick (CVD event). Obviously a HCP would recommend diet and lifestyle to remedy high LDL, however some with familial hypercholesteremia or that have higher than normal risk factors, like family history of early CAD might need a compound like statins to even the playing field with the genetic cards they were dealt (Dr. Pearson has talked about this in another blog post).

    The other side to that coin is, herbs and supps are looked at as preventative, we take our vitamins and we eat “NATURAL healthy stuff” like herbs and compounds from veggies (in pill format) to stave off the complications of aging.

    As a preventative cardiologist, your words of wisdom along with education about how Rx’s can function as supplements (QOL improvement, longevity) to a healthy lifestyle (eating balanced diet, maintaining a normal BMI, good sleep habits, and having healthy relationships) can make a real difference in changing the perspective that certain drugs are only for “sick” people and they can in fact be much more safe and efficacious than their “natural” counterparts. Since I started reading this blog I believe that this has always been a core tenet in your writings and I hope others see that message as well.

  2. Many people attribute improvements after “natural” self-treatments to the medicinal qualities of the substance(s) they choose to take when the improvements are actually due to the placebo effect. This is fine if the “natural” substances are harmless and you aren’t spending money you need for other expenses or failing to take needed proven medicines.

  3. I agree with most of the points in this post, but I would like to point out that non-medication treatments rarely have the chance to be studied in controlled trials because drug companies cannot patent them and thus there is no financial incentive to do so. The only vitamin to treat a disease is L-methylfolate under the brand name Deplin approved for depression.

    I have a high lipoprotein (a) level, a strong risk factor for CVD. It’s determined by genetics and there is no FDA approved treatment. I had to come up with my own treatment. I settled on high dose immediate release niacin and Zetia. I have lowered my level by over 50%, something they said was impossible! The treatment for a high homocysteine is four B vitamins because high homocysteine is very bad for your brain and it runs in my family. Any level over 10 is bad and my level was once 27. My mother had Alzheimer’s disease at my age. I have dropped it to 8 using these four B vitamins. Thus non-medication treatments can play a critical role in managing certain health problems.

  4. Many times I have complimented and criticized ACP: here he is off base again, which I excuse because of his past excellence, his current youth, lack of knowledge, and inexperience. Herbal Red Yeast Rice in proper dose is quite effective in reducing nonHDL cholesterol. Danshen is effective as is hawthorn, and just today I mailed an article to our cardiology fellows about green tea reducing p53 activity. There are a gazillion herbal benefits, as well as some downsides as all vitamins, minerals, herbs, supplements, & prescription medications have. But I do agree wi ACP that there is much commercial hyping. As usual, caveat emptor: be schooled. HRS, MD, FACC

  5. What about something like Citrus Bergamot? Multiple studies show promise:

    What does it take for something like this, that does have some research backing it, to cross over into the realm of a reasonable alternative? Larger studies? Certainly the financial motivation is not there like there would be if it were a new drug.

    The supplement market is dumpster fire. So many products on Amazon with seals galore on them touting their quality, and pleasant-sounding names with pictures of people in natural settings. But try to track down actual certificates of analysis, even when they claim to have them, and you’ll see how bad the state of things actually is. Best case, you can find them right on their website, and they are current–that is quite rare. I’ve seen everything from years old CoA’s, to no CoAs, to the company is just a shell company with a crappy content-less website. God only knows what’s in these products with so much of it sourced from China. There are many products with USP bogus claims–yet look how short the list of actual USP certified companies is:

    Unfortunately, unless/until people demand better, it doesn’t look like anything will change. Good luck with that, eh?

    Buyer beware…

    • CJ,
      I’ve looked at bergamot a lot because I’m a fan of Earl Grey tea. Reviews like the one you cite are generally in very weak, predatory journals and raise the promise that some component of bergamot could be effective in lipid lowering. I outlined the issues with red yeast rice which (sometimes) contains an actual statin in a post (. )
      After detailing the history of the discovery of statins in red yeast rice my comments ended with

      Problems With Alternative Medicine In General

      These problems with RYR supplements are typical of all supplements.As the the authors wrote

      “Our results highlight an important issue with red yeast rice and many other alternative medicines: the lack of standardization of active constituents. Standardization of ingredients is difficult for several reasons: (1) There are variable growth and/or culture conditions and differences in harvesting and processing among manufacturers; (2) medicinal agents from natural sources are complex substances with many chemical constituents, many of which have unclear roles in their pharmacologic activity; and (3) different manufacturers may standardize products to amounts of 1 or 2 chemicals thought to be active ingredients, while other constituents are not standardized and may also have biologic and pharmacologic activity.”
      One has to ask, given this background, why would a patient choose to take a “natural” OTC supplement containing an unknown amount of both a). Effective cholesterol lowering chemicals and b)potentially toxic extraneous chemicals over the precisely formulated, carefully regulated, fully studied, pure statin drug available by prescription.

      It’s especially baffling to me when one considers that lovastatin comes from RYR. Thus it would have to be considered “natural.”

      Akira Endo spent decades carefully identifying the effective and safe chemical portion of RYR. It is now available as a generic costing pennies per pill.

      We know exactly how many milligrams you are consuming. We know what benefits to expect and what side effects can occur based on studies in hundreds of thousands of patients who have taken a similar dosage.

      You are much better off taking the prescribed statin drug than RYR.

      • Thanks for pointing out the journal issues. I went and read up on predatory journals and tried to evaluate that journal. It is quite difficult for non-experts like me to establish that this is a predatory journal. The journal charges a high ACP fee than is in line with non-predatory journals, it has a sizeable board of editors, the journal isn’t on Beall’s list of known bad, but it also isn’t on a DJOA known good list, it claims to follow ICMJE practices. It’s unfortunate that it is so difficult, especially for non-experts, to draw conclusions from research articles.

        • CJ,
          There has been a dramatic proliferation of scientific journals in the last decade. Although I have only published one significant paper in the last 20 years I am constantly getting invitations to be on the board of editors for journals and constantly being invited to publish with them. Basically, if you are willing to pay the money, you can get anything published in lots of journals.
          And it is very difficult to sort out the good from the bad.
          Dr P

  6. Question re Medtronic MICRA AV, I was diagnosed w Supra Ventricular Tachycardia in September 2020.

    Following immediate cardio version which failed in October, I had ablation in December 2020. It was incomplete because my EP cardiologist found cells too near to the AV node to risk ablation at the same time.

    Following continued arrhythmia in January & February, keeping me awake nights, he put me on Multaq & metoprolol, plus Eliquis, and agreed at my request — after I had extensively reviewed the MICRA AV — to a) ablate the AV node & b) install the trans catheter MICRA AV, scheduled for March 2.

    I have great faith in my EP cardiologist. He has 23 years in practice & was rated in the 92nd percentile for general electro physiology by HealthGrades. Our regional hospital is ranked in the top 50 for cardio by both US News & HealtGrades. My echo cardio gram puts my estimated ejection rate 55-60%. A lifelong runner & swimmer, I’m 81.

    I had initial phone conversation with Mayo Clinic’s cardio intake, which was positive, but my Aetna case manager says our regional EP group is just as good.

    I am blown away by Medtronic’s claim on it’s AV website: beyond being trans Cather installation, 99% implant success, leadless, extremely small, the MICRA integrated circuitry Accelerometer “detects mechanical atrial activity & uses this information to deliver AV synchronous ventricular pacing.”

    To me, it’s almost too good to be true. Could I in fact have a new lease on life & expect to be swimming again by June? What am I missing? What’s your experience, if any, with the MICRA AV?

  7. Hi Anthony, I’ve been following and enjoying your blogs for over 2 years now. Keep up the good work!

    This blog touches on a subject that is also dear to my heart: pseudo- or non-science.

    However, big pharma is a long way from being blameless in the situation we find ourselves. When you say: “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…” I would suggest that this statement should be qualified. As Ben Goldacre describes in his book “Bad Pharma”, the drug companies have been very guilty of all kinds of dubious practices, including, for example canning trials before they’re finished if they think it isn’t going to give them the result they want, and not publishing their data; or segmenting the data in a manner not envisaged when the trial was designed. So I believe we should be extra skeptical at least about efficacy claims, and if it’s really important for your health (life or death even) that the drug being prescribed does what it claims, investigate the evidence for its efficacy. Difficult for the unqualified, no doubt, but if your quality of life is really at stake…??? At least one could have a rational dialogue with one’s physician on what she/he knows about the data on which its efficacy claims are based.

  8. Avoid “Nighttime” teas or others sweetened with licorice root if you are hypokalemic or are taking loop diuretics. Docs know the Lasix/licorice admonition, but people don’t usually think about it in tea.

  9. Foxglove is so purty; I have a ridiculous postage-stamp of a garden in my back yard jammed with too many plants most of which my late wife insisted we plant (with zero organizing principle). Still intend to find a corner for some foxglove. I’ve heard it is self-propagating–wonder if that’s your experience. Oh, and I wouldn’t brew tea with cedar (although I might with slippery elm bark); but as a longtime mediocre guitar player I can attest to the ancient argument as to whether cedar or spruce makes a better soundboard.
    Loved the story of Withering and Gelert!

  10. Thanks for sharing! A quick look at the article in question shows evidence of referencing. In addition, and there seem to be a number of scholarly research articles confirming the positive effects of the melon-derived SOD. I am fairly new to scientific writing and lack experience in assessing research, and I wondered what led you to your belief that the original article was quackery. Are the references and research poor quality? Or is it simply that further research is required before the supplement could be recommended?

    Thanks again,

    Gill (Nutritional Science BSc student)

    • Gill,
      I evaluated the Life Extension site extensively in 2017. They do an excellent job of presenting the appearance of scientific support for their numerous unproven supplements. There are frequent links to very preliminary papers in very weak journals which present some evidence that the chemical/nutraceutical/supplement Life Extension is selling is useful. None of these links provide any evidence to prove benefit to human health. Often the links don’t even support the statements they are linked to.
      For any of these supplements to support a human health claim, much higher level of evidence is required. Unfortunately, since there is no regulation of the nutraceutical industry they continue to get away with this outrageous hucksterism.
      Dr P

  11. What would you recommend for someone who can’t take statens? I developed AIH when I was on them. Now I am very hesitant about taking anything.

    • For patients who require drug treatment to lower risk of atherosclerotic disease and can’t tolerate statins, the next step is typically ezetimibe followed by the PCSK9 inhibitors.


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