The “Science” and Ethics of “Natural Medicines” (and Nutrition) cont.

This is the continuation of a discussion concerning the explicit claim of “naturopathic physicians”* to being experts in the use of “natural medicines,” defined as “medicines of mineral, animal and botanical origin.” Last week’s post established that the cult has chosen to profit from the “retail selling of medications,” as evidenced by the relevant Position Paper of the American Association of Naturopathic Physicians (AANP) and by that organization’s having made a deal with a drug company to make profits for both itself and its members.

The Position Paper observes that such selling “could be construed as a conflict of interest on the part of the physician.” That is true, if embarrassingly understated: anyone representing himself as a physician, who both recommends and sells the same medications for a profit, has conflicting interests. The conflict undermines his claim to offering responsible advice regarding those medications, and as such is a breach of medical ethics.

The AANP’s deal with was even worse: by promoting such peddling in a formal, institutional fashion, NDs and their national organization went beyond the already widespread problem of practitioners hawking drugs. It is unclear whether the deal still exists, by the way: was a victim of the “dot com” bust of a few years ago. It has since been resurrected, but a quick perusal of its new website fails to reveal the old AANP relationship. Nevertheless, I have seen no evidence to suggest that the AANP has changed its view of that sort of deal.

Are NDs Truly “Learned Intermediaries” in the Use of “Natural Medicines?”

This entry discusses the other part of the claim of expertise: that, aside from their conflicting interests, NDs have real knowledge of “natural medicines.” It will become clear during the discussion that the purported naturopathic expertise in nutrition—another standard claim—is also under review. I will include or cite abundant evidence for my assertions, because I’ve found that a predictable response of representatives of the highest levels of “naturopathic medicine” is to flatly deny them. I apologize again for including excerpts from previously published material.

The AANP Position Paper

All by itself, the previously-mentioned AANP Position Paper on Sale of Medications by Physicians provides substantial evidence against a claim of expertise:

II. There are numerous references in the medical literature that document the existence of subclinical disease and the fact that the chances of anyone consuming a diet that meets the RDA for all nutrients is extremely unlikely.

III. There are numerous citations in the medical literature about the efficacy of homeopathic, botanical and other natural substances as medications to be used in the treatment of disease. It is common knowledge that many of the medications prescribed by Naturopathic Physicians (such as homeopathic and botanical medications as well as certain nutrient supplements) are not available elsewhere.

“Subclinical disease” certainly exists, but it is not those that are trumpeted by NDs: “chronic candidiasis,” bogus “food allergies,”  “leaky gut syndrome,” “toxin overload,” “weak immune system,” bogus “vitamin deficiencies,” “subclinical thryoid dysfunction” such as “Wilson’s Temperature Syndrome,” and more. It is categorically untrue that “the chances of anyone consuming a diet that meets the RDA for all nutrients is [sic] extremely unlikely.”

Although there may be “numerous citations in the medical literature about the efficacy of homeopathic, botanical and other natural substances as medications to be used in the treatment of disease,” (italics added), there are none that establish such efficacy for homeopathy (and never will be), and precious few that support the other substances in their “raw” states.

“Identifying Best Practices”: the Textbook of Natural Medicine

The Textbook of Natural Medicine (TNM), now in its 3rd edition, is co-edited by NDs Joseph Pizzorno and Michael Murray. Pizzorno is “Co-founder and past president of Bastyr University,” and is probably the most conspicuous ND in the public domain. Murray is a member of Bastyr’s board of trustees and presides over what appears to be an impressive conglomerate of on-line emporia selling snake oil and medical mis-information. A pitch on the Bastyr website for the 2nd edition of the TNM,[1] the one discussed here, proclaimed:

The 2nd edition of the Textbook of Natural Medicine … is the most comprehensive and widely-referenced text available on natural medicine. It covers a wide range of approaches for managing and treating over 100 conditions and health problems.

The first edition was reviewed in The Journal of Alternative Medicine as “the ultimate book on naturopathic medicine.”

The TNM itself asserts that

This Textbook, with some 10,000 research literature citations, provides well-documented standards of practice for natural medicine.

On its back cover is an endorsement by homeopath Wayne Jonas, the former Director of the NIH Office of Alternative Medicine:

The Textbook of Natural Medicine is the most comprehensive summary available of the actual practices and recommendations of naturopaths and complementary practitioners.

In a presentation to the Institute of Medicine in 2003, Timothy Birdsall, ND, representing the AANP, presented a slide with the heading “How do you identify best practices and communicate those practices to the field?” Immediately underneath was the first answer:

• Text and Reference Books

–Textbook of Natural Medicine, by Pizzorno & Murray

I’ve made a point of demonstrating that the TNM is representative of the tenets and practices of “naturopathic medicine” because, as mentioned above, each time I’ve quoted it or other representative treatises, I’ve been accused of misrepresenting what NDs really do. Well excuse me, but that will just not do. Such accusations, coming as they have from the highest levels of the cult, indicate a systematic dishonesty.

A Quasi-Scientific Study by Me

The 2nd edition of the TNM comprises about 1600 pages; about 500 are devoted to “Pharmacology of [~60] Natural Medicines,” and additional assertions about those and more are scattered generously throughout the book, including in each of the approximately 80 chapters devoted to “Specific Health Problems.” Having established the TNM as exemplary of the best practices of “educated naturopaths,” it is reasonable to examine what it has to say about those substances. When I was on the Massachusetts Special Commission, I compared the TNM’s assertions of safety and efficacy to those found in a source that bases its findings on peer-reviewed literature: the Natural Medicines Comprehensive Database (NMCD). This was the best source that I could find, even though it skims over problems inherent to “raw” botanicals, as does “herbal medicine” in general, and even though it ignores prior probability, as is the norm for Evidence-Based Medicine.

The NMCD ranks medicines for safety and efficacy, and discusses possible mechanisms of action, contraindications, and interactions with other drugs and disease states. Only the “effective” category suggests efficacy equivalent to FDA-approved drugs. The “likely effective” category suggests that the substance shows some promise. The “possibly effective” category suggests only that the substance might work. To continue the analogy with FDA-approved drugs, consider that the vast majority of “possibly effective” drugs would never win FDA approval.

The following table shows the results of comparing the two sources’ evaluations of 13 substances. All page numbers refer to the TNM, 2nd edition. [1] I chose a cross-section of “natural medicines”: a few based on general familiarity, others based on naturopathic claims for common medical problems, and still others reflecting the less-familiar categories of “animal and mineral origins.” I did not include every purported use for each substance. I chose the examples before making the comparisons (the reader will have to trust me about that), thus avoiding a bias for substances and uses with particularly large discrepancies between the two sources of evaluation. Nevertheless, the “study” cannot claim to have escaped the possibility of significant sampling error—although the subsequent discussion ought to convince readers that this is unlikely. A further limitation of this comparison is that it was made in 2001; subsequent information must alter some of its implications—to the further detriment, I suspect (because I haven’t looked at the 3rd, 2005 edition), of the claims of the TNM. The results:

Comparison of NDs’ “Best Practice” Claims for “Natural Medicines” with a Rigorous Standard (The Natural Medicines Comprehensive Database)

Substance Use by Naturopaths Effectiveness acc. to the TNM Effectiveness acc. to the NMCD Notes, including safety
Goldenseal UTIs Recommended: “Goldenseal is one of the most effective of the herbal antimicrobial agents” p. 1187 “Berberine from goldenseal is thought to concentrate in the bladder, so theoretically, it might have some activity against urinary pathogens; however, this has not been demonstrated in humans.”(see my correspondence) NMCD: Likely unsafe used long-term or in high doses (“cardiac damage, spasms, and death”), and in newborns. Unsafe in pregnant women. Unsafe for breast-feeding mothers.TNM: “not recommended for use during pregnancy and higher doses may interfere with vitamin B metabolism.” [p. 780] No other warnings. The recommended dose range in the TNM (2-4g dried root TID) [p. 780] overlaps with the toxic dose range given in the NMCD (as low as 8g of dry root, depending on the concentration). The TNM quotes the oral LD50 for berberine in rats as >1000 mg/kg body wt., “indicating that the toxicity is extremely low.” [p. 780] According to the NMCD, however, “The LD50 of the berberine constituent in humans is reported to be 27.5 mg/kg.”Note: the entire discussion of goldenseal in the TNM (ch. 91) is an exercise in sophistry. Sweeping clinical generalizations are based on simplistic reasoning and the slimmest of evidence. This is the real significance of the “10,000 scientific references” claimed for the entire textbook.
“Strep throat” “may be ideal in the treatment of ‘strep throat'” [p. 777]–based on a single in vitro study of adherence of bacteria to epithelial cells Not studied
Licorice “Viral infections (e.g., common cold, HIV and AIDS, viral hepatitis)” [p. 769] Common cold: “historical use is justified by its immune-enhancing and antiviral effects” [p. 769]HIV: several small, inconclusive studies cited [TNM p. 769]”impressive results in treating chronic hepatitis B” [p. 770] Possibly effective for upper resp. tract inflammation; insufficient reliable information for other claims. NMCD: Unsafe in pregnancy (abortifacient). Not recommended in lactating women. Contraindicated in multiple disease states, including: diabetes, heart disease, high blood pressure, several cancers, hypokalemia, renal (kidney) insufficiency, cholestatic liver disease and cirrhosis and male sexual dysfunction. Multiple drug interactions cited.TNM: No mention of pregnancy or lactation. Correctly states that main side effects due to aldosterone-like action, but suggests these can be avoided by a high potassium diet, “although no formal trial has been performed.” Says licorice should probably not be used in patients with a history of hypertension or renal failure or if on digitalis preparations. No mention of other contraindications.
Premenstrual syndrome “particularly useful” [p. 1509] Insufficient reliable information
“ulcerative conditions of the GI tract (e.g. peptic ulcers, canker sores, and inflammatory bowel disease) “Numerous clinical studies over the years have shown DGL (deglycyrrhizinated licorice) to be an effective anti-ulcer compound.” [p. 771] “Studies using DGL for ulcer treatment have been inconclusive”; insufficient reliable information for other claims.
Thymus extract Preventing recurrent URIs Effective [p. 332] Possibly effective Made from raw bovine thymus glands; potentially can transmit disease, including BSE (mad cow disease). No mention of this in the TNM. NMCD recommends against use in immunosuppressed states, incl. HIV, unless “certified pathogen-free.” No mention of this in the TNM. The prior probability of bovine thymus cells being effective treatments for immunosuppressed states in humans approaches zero.NMCD refers to real food allergies
Correcting “T-cell defects” in HIV Effective [p. 332] Insufficient reliable information
Restoring # of peripheral leukocytes in cancer patients with low WBC counts due to chemotherapy Effective[p. 332] Insufficient reliable information
Allergies, incl. asthma, hayfever, and food allergies in children Effective [p. 332] Possibly effective
Echinacea “General infectious conditions” “Proven efficacy” [p. 707] Insufficient reliable information NMCD warns against use in pregnant women. TNM makes no mention.
Influenza “Proven efficacy” [p. 707] Possibly effective
Colds, treatment “Proven efficacy” [p. 707] Possibly effective
Colds, prevention Implies efficacy: cites one obscure study in favor [p. 708] Possibly ineffective. Multiple negative studies cited.
Urogenital infections “Proven efficacy” [p. 707] Possibly effective for vaginal yeast infections only
“Other infectious conditions” “Proven efficacy” [p. 707] Insufficient reliable information
Snake bites Admits there are no studies, but still lists as “other application” [p. 708] Insufficient reliable information
Wound healing “Several uncontrolled studies have been reported to substantiate Echinacea’s wound healing activities.” [p. 708] Insufficient reliable information
Arthritis Echinacea’s anti-inflammatory activity has been shown in uncontrolled studies to be useful in rheumatoid arthrititis.” [p. 708] Insufficient reliable information
Cancer “Extracts have been shown to inhibit the growth of Walker carcinoma and lymphocytic leukemia in experimental studies.” [p. 708-The reference for this statement was an in vitro study for the Journal of Med Chem in 1972] Insufficient reliable information
Vitamin C Colds, treatment “Well-known effects” [p. 482] Possibly effective in modestly reducing the duration The TNM recommends vitamin C for virtually everything (see index). The vast majority of these claims have not been studied but are highly implausible, because vitamin C, like most vitamins, is a co-factor for enzymatic processes. What that means is that it is required in small concentrations and is not used up by the those processes. Thus it is unlikely on its face that megadoses will be superior to modest ones. Its only proven role, to prevent or cure scurvy, is entirely consistent with that biochemical fact.  The NMCD warns against doses higher than the RDA (70 mg/day) in pregnant women, which can lead to scurvy in newborns. The TNM mentions this, but advises an upper limit of 500 mg/day for pregnant women. [p. 1017] The NMCD lists several contraindications and potentially harmful drug interactions; these are not mentioned in the TNM.
Colds, prevention “Well-known effects” [p. 482] Possibly ineffective
Otitis media Recommended [p. 1456] Insufficient reliable information
Cancer prevention “Linked to a reduced risk of cancer of the cervix, stomach, colon and lung” [p. 836] Possibly ineffective
Male infertility Very effective [p. 1383] Insufficient reliable information
Magnesium and vitamin B6 (pyridoxine) Prevention of calcium oxalate kidney stones Recommended [p. 1367] Possibly effective:”There is some evidence that magnesium in combination with pyridoxine can decrease urinary oxalate levels in people with hyperoxaluria and who have previously had kidney stones. However, it’s unclear if this effect translates into a significantly reduced incidence of kidney stones.”  
Premenstrual syndrome Effective and recommended [pp. 1506-1508, 1510] Possibly effective
Diabetic neuropathy Effective and recommended [p. 1209] Likely ineffective
Turmeric Arthritis Effective and recommended [pp. 1448, 1530-31] Insufficient reliable information The TNM warns against aspirin and NSAIDS (such as ibuprofen): they “appear to accelerate the progression of osteoarthritis.” [p. 1443] This is false.
  • Angina
  • Maldigestion
  • Arthritis
  • Pancreatic insufficiency
  • Athletic injury
  • Phytobezoar
  • Bronchitis
  • Pneumonia
  • Burn Debridement
  • Scleroderma
  • Cellulitis
  • Sinusitis
  • Dysmenorrhea
  • Staphylococcal infection
  • Ecchymosis
  • Surgical trauma
  • Edema
  • Thrombophlebitis

–Table on p. 621

All: “Documented clinical efficacy” [p. 621] Possibly effective for osteoarthritis if taken “orally as a specific combination with trypsin and rutin”; possibly ineffective for myalgia (muscle pain); insufficient reliable information for knee pain, trauma, and ulcerative colitis. Other claims in TNM not mentioned. The NMCD warns against several interactions with supplements and pharmaceuticals; these are not mentioned by the TNM.A common claim of NDs, that “a digestive enzyme such as the popular bromelain, enters the bloodstream and clears out products that contribute to inflammation” [when taken orally] is highly implausible, because enzymes, which are proteins, are almost entirely broken down in the GI tract.
Vitamin E Menopausal syndrome; hot flashes Recommended, citing three papers from the 1940s. [p. 1392] “Supplemental vitamin E appears to have little effect on reducing hot flashes in women who have had breast cancer. There have been no clinical trials using vitamin E supplementation for postmenopausal symptoms.”  
St. John’s Wort Depression Recommended [pp. 800-802] Likely effective St. John’s wort is dangerous for HIV+ patients taking life-saving protease inhibitors, because it causes the liver to metabolize them to the point of ineffectiveness. This information was not yet available to the authors of the 2nd (1999) edition of the TNM, but it demonstrates the potential mischief that incautious, premature recommendations can cause. Moreover, although the drug interaction became known in 2000, the Bastyr website has continued to publish language that could easily lead an unwary HIV+ person to take SJW, because it misrepresents the issue: “many of these agents have yet to be systematically evaluated for…interactions with highly active antiretroviral therapy (HAART).”
AIDS Touts anti-retroviral activity [pp. 800, 803, 1287]; “highly recommends” St. John’s wort as an antidepressant for HIV+ patients. [p. 1287] Possibly ineffective
Colloidal Silver Opportunistic bacterial and yeast infections in AIDS patients Recommended: “Electrochemical Ag+ solutions exhibit antimicrobial effectiveness ” [p. 1292] The authors base this recommendation on an in vitro study of silver as a preservative. Insufficient reliable information This is a well-known, toxic heavy metal: “According to the FDA final rule, no over the counter products containing colloidal silver are generally recognized as safe”-NMCD
Garlic “Natural antibiotic,” “immune-enhancing effects,” anti-cancer effects, lowering cholesterol, lowering blood pressure, lowering blood sugar in diabetics, and more. All of these claims are exuberantly endorsed. [pp. 571-577] The chapter on AIDS claims that garlic is “effective against herpes virus, and cryptococcal, mycobacterial, and candidal organisms,” citing several in vitro studies. [p. 1292] Possibly effective in modestly reducing cholesterol and LDL, but no evidence that this translates to reduction in heart disease, and not nearly as effective as FDA approved “statin” drugs. The effect may disappear after six months.Possibly effective for modestly lowering blood pressure.Possibly effective for reducing some cancer risks, but studies are controversial.Possibly ineffective for diabetes.Insufficient reliable information for other uses. Like SJW, “Garlic can substantially decrease plasma concentrations of the protease inhibitor saquinavir. Since NNRTIs and protease inhibitors are metabolized through similar routes, NNRTIs might also be affected. Patients taking these medications should avoid using garlic.”-NMCD. In other words, garlic is contraindicated in HIV+ patients taking protease inhibitors, the very patients that the TNM recommends use garlic for its alleged antimicrobial effects. As was the case for SJW, this interaction wasn’t known until after the 1999 edition of the TNM was published; but again, it demonstrates the foolishness of premature recommendations, and again, the Bastyr website continues to post language that might persuade the unwary HIV+ individual to take garlic pills, by touting a human trial of “Garlic for hyperlipidemia caused by high active antiretroviral therapy (HAART)” that was apparently continued (but never completed) even after the investigators, including some from U Washington, had acknowledged this dangerous interaction.

The comparisons are not favorable to naturopathic claims. Only a few agents and indications that are highly touted by the Textbook of Natural Medicine received even a “possibly effective” rating by the NMCD. Some received a “likely ineffective” rating. For the vast majority, there was “insufficient reliable information” to come to any conclusion. An example is vitamin C. It is recommended for nearly one hundred non-standard indications in the TNM, but according to the NMCD is “possibly effective” for only one: modestly reducing the duration of the common cold. For the rest it is either “likely ineffective” or there is “insufficient reliable information” upon which to base any conclusion.

Most of the claims in the Textbook of Natural Medicine are grossly exaggerated and based not on human studies but on simplistic speculations occasionally supported by in vitro (“test tube”) studies or animal studies. Frequently, claims for vitamins are extrapolations from their role in reversing the classic vitamin deficiency states, but these aren’t applicable to patients who are not vitamin deficient. An example, in the Textbook’s discussion of glaucoma, is on p. 1250:

Of foremost importance in achieving collagen integrity are optimal tissue concentrations of ascorbic acid [vitamin C].

This is not strictly false, but is irrelevant unless the patient is suffering from scurvy, and it has nothing to do with the pathogenesis of glaucoma. To illustrate the point, consider that water is also “of foremost importance in achieving collagen integrity,” but more of it than usual will neither prevent nor treat glaucoma. Notice the implications of this, and of my comment in the table about how vitamins work, for naturopathic pretensions to expertise in nutrition.

Here is an instructive correspondence that I had at the time with one of the editors of the Natural Medicines Comprehensive Database:

From: “Kimball Atwood”
Subject: hydrastis canadensis
Date: Mon, Jan 29, 2001, 8:54 AM

According to the Textbook of Natural Medicine (Pizzorno and Murray, Churchill Livingstone, 1999), “Goldenseal is one of the most effective of the herbal antimicrobial agents. Its long history of use by herbalists and naturopathic physicians for the treatment of infections is well documented in the scientific literature.” Your monograph mentions only a suggestion of this in the “people use for” field, and nothing at all about it in the “effectiveness” field. Is the statement in the Textbook incorrect?

Kimball Atwood, M.D.

Hello Dr. Atwood,

We often find that our standards for suggesting a given natural product is effective or not are much higher than that typically found in the “naturopathic” literature. Often with the Textbook of Natural Medicine and other similar references, it is implied that products work for certain conditions based on in vitro or animal data. This is the case with goldenseal (Hydrastis canadensis). In some cases, studies with an isolated and purified constituent of goldenseal (berberine) have also been used to imply that goldenseal is effective.

Goldenseal is promoted for everything from viral infections to bacterial to fungal infections. Unfortunately, there is almost no clinical evidence that it works for any of these conditions. We do not make the leap from animal data and in vitro data to say that natural products work for a given condition. Furthermore, as you will see in our Mechanism of Action section, there is some evidence that the active constituent of goldenseal probably doesn’t reach serum levels adequate to have a clinically significant effect.

Take care,

Philip J. Gregory, Pharm.D.
Assistant Editor
Natural Medicines Comprehensive Database

The Natural Medicines Comprehensive Database also appears to use a “much higher” set of standards in discussing safety. Just as efficacy is exaggerated in the TNM, dangers are minimized. This is especially true for uses of agents in pregnant or breast-feeding women, which are rarely mentioned by the TNM but frequently cautioned by the NMCD.

The major safety issue having to do with largely ineffective “natural medicines,” of course, is their being substituted for other, truly effective, medicines. When this is done for patients with serious illness, disastrous outcomes can occur. The Textbook of Natural Medicine and other naturopathic treatises recommend such substitutions repeatedly, as exemplified in the links below.

More Examples and Expert Opinion

Can be found here. A review of the TNM by Arnold Relman, the emeritus editor of the New England Journal of Medicine, can be found here. More examples from the AANP Position Papers and the TNM, including language that would certainly lead to a recrudescence of now-rare rheumatic heart disease and a comprehensive look at the level of “evidence” that the TNM brings to bear for its claims about omega-3 fatty acids, can be found here. More discussion of the “research” collaboration between the NCCAM and Bastyr University, which includes several absurd and dangerous “natural medicines” studies, can be found here.


The common claim, made by “naturopathic physicians” and their apologists, that they are trustworthy experts in the use of “natural medicines” and “therapeutic nutrition,” is without basis in either medical ethics or science.

1. Pizzorno JE and Murray MT (eds.) Textbook of Natural Medicine (TNM), Churchill Livingstone, Edinburgh, 1999


*The Naturopathy Series:

  1. “CAL”: a Medico-Legal Parable
  2. Another State Promotes the Pseudoscientific Cult that is “Naturopathic Medicine.” Part 1
  3. Another State Promotes the Pseudoscientific Cult that is “Naturopathic Medicine.” Part 2
  4. Another State Promotes the Pseudoscientific Cult that is “Naturopathic Medicine.” Part 3
  5. Another State Promotes the Pseudoscientific Cult that is “Naturopathic Medicine.” Part 4
  6. Colorado is Nearer to Promoting Naturopathic Pseudomedicine—Aided by the Colorado Medical Society
  7. Naturopathy and Liberal Politics: Strange Bedfellows
  8. Open Letter to Dr. Josephine Briggs
  9. Smallpox and Pseudomedicine


Posted by Kimball Atwood