Cover story articleHerbal supplement

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St. John's wort
Against allopathy

Alternative medicine

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Herbal supplements are non-pharmaceutical,[1] non-food substances marketed to improve health. Herbalism (herbal medicine, botanical medicine) is the use of plant-derived substances, and sometimes other environmental substances, to treat or cure medical conditions. Herbalism recognizes that pre-industrial cultures had a great deal of practical medical knowledge, most of it botanical, and seeks to make use of this. Definitions are problematic. There are no unified practices, no enforceable standards for strength or purity, and relatively few guidelines for practitioners.[2] Also, there is no clear definition of what an "herbal remedy" is. A large number of currently available drugs are originally plant-derived, which means herbalism is basically pharmacology's petulant, stubborn little brother.

Contents

History

Humans have used botanicals for medicinal purposes as far back as archaeological evidence exists. About 30% of all FDA-approved drugs are derived from botanical sources.[3] Examples include aspirin (from willow bark) and digoxin (from the foxglove plant). Molecular biology has allowed for more directed drug development. For instance, the active ingredient in a plant extract can be identified, isolated, and replicated. The molecule can also be modified to add desired effects or eliminate undesired effects. Sometimes molecules are altered in order to develop a drug just different enough from the old medication to allow a new patent to be issued. "Reverse" development is also done, where a receptor in the body is identified, and computers assist in identifying molecules to fit these receptors. In sum, many modern medicines started as plant extracts and were refined to improve the medicinal characteristics, including reducing toxicity.

Currently, approximately 12-25% of Americans use an herbal remedy yearly.[4] Despite their popularity, these substances, advertised as medically active, are regulated as dietary supplements, rather than as medicines by the FDA. This means that there is very little regulation of the manufacturing or content of these substances. In Canada every natural product must apply for a natural product number (NPN) and are now governed under the Natural Health Product Regulations, which include provisions on adverse reaction reporting, labelling, and site and product licencing.[5]

Americans, however, often perceive herbals as "safer", "more natural", and "more holistic" than conventional medications. Also, many are suspicious of the profit motive of the pharmaceutical industry. Herbal medications do, of course, represent an enormous financial interest. Echinacea alone has annual sales of about $300 million in the U.S.[6]

Effectiveness

Many studies have been done of herbal medications. Unfortunately they often lack good documentation, quality, and suffer from not having analyzed the substance studied.[7][8] Because of the lack of quality control and regulation, it is difficult to assess what the effect of many herbs is, or even what people may be taking, given the label often fails to match the content.

Given these limitations, a summary of studies of some popular supplements is listed below:[9]

  • Milk Thistle seems to have proven results in reducing liver inflammation in children undergoing chemotherapy[10][11]
  • Ginkgo is sold as a "memory aid" and a treatment for Alzheimer's disease. Studies show mixed results, with a possibility of it being better than placebo
  • Saw palmetto: marketed as a treatment for benign prostate disease in men, studies show some effect greater than placebo, at least in the short term
  • St. John's Wort: used for depression, data show short-term efficacy over placebo for mild to moderate depression.
  • Ginseng: many different types, insufficient data
  • Echinacea: marketed for the common cold, no good, consistent studies have been done.
  • Evening primrose oil: for PMS, studies show no benefit
  • Ginger: insufficient data, though used as a classic stomach ache cure.
  • Garlic: insufficient data, claimed to help with heart health. If nothing else, it will repel vampires.
  • Kava-Kava (or just Kava): marketed for anxiety, some improvement over placebo, side effects
  • Valerian root: for insomnia: does nothing[12]
  • Cranberry juice: for prevention of Urinary Tract Infections: well demonstrated and well documented efficacy[13][14]
  • Rose Hips: Good for getting an extra dose of Vitamin C, but unproven for anything else.

For a more detailed description see Herbs and Spices (List)

Potential harms

Much of the time, herbal remedies are used without consulting a physician about the condition in question. This may lead to delay or failure of diagnosis of important medical conditions. For example, a man who takes saw palmetto for his urinary problems may have all the signs and symptoms of prostate cancer, but if he feels better after taking the saw palmetto, he may not be diagnosed until it is too advanced for treatment. Herbs can also interfere with conventional medications.

As herbs have become more popular, and as more have become available with globalization, more toxic effects are being seen. Herbal preparations may or may not resemble the traditional cure from which it was derived, and are often used in a different context. For instance, small amounts of Mahuang may exist in certain Chinese medicines, but is used in much higher concentrations in the West. Many common herbs can be quite toxic, and may exist in supplements without clear labeling. For example, Mahuang can cause serious cardiac disturbances and Kava can injure the liver. New reports come out regularly about liver failure caused by herbal remedies. Herbal remedies from outside the U.S. are sometimes contaminated with lead and other heavy metals.

Many herbal medicines can interfere with traditional medications. For example, St. John's Wort is a potent inducer of the cytochrome P450 System. This can increase the rate at which the liver metabolizes drugs, leading to a dangerously low level of drug in the body.[15]

Some typical woo

"Experienced wine drinkers can tell the difference in taste between an expensive and inexpensive wine, but chemical analysis would probably not indicate much of any difference. In the same way an herbal tincture that is well prepared from whole plants by a knowledgeable person provides a medicine that is not able to be chemically analyzed as different, but is far superior to anything standardized on the basis of an ingredient that may not even be active."[16]

That chuckling sound you hear distantly to the east is Hervé This[17] laughing his ass off at the above assertion.

Safety

It is interesting to note that organisations selling herbal remedies will almost always make a statement along the lines of "natural is safe". This statement takes many different forms, but is usually directed as a slur to the pharmaceutical industry claiming that OTC and prescription drugs are secretly harmful but because their products are naturally derived, no ill effects can be possible. Basic knowledge of toxicology will quickly refute this generalised claim, as almost all of the most toxic substances on earth are natural in derivation.[18]

Summary

Many herbal remedies have significant medical effects. Labeling may not correctly describe the contents of the medication. The preparations available are not well-regulated or well-studied. As such, they are often wasteful, or even toxic. When there is a measurable effect, it is often more modest than the available conventional medicines.[19] Many companies are doing large scale testing of botanicals to look for biologically active substances. Older remedies, and new ones, as discovered, should be subject to the same scrutiny as any other medication. There is no reason to believe that herbal remedies have any "natural" advantage over conventional ones. Randomized controlled trials can distinguish good medicines from bad, independent of the source.

See also

External links

Footnotes

  1. The term "supplement" allows them to avoid medical laws, while still allowing "health benefits" to be promoted.
  2. The United Kingdom has a National Institute of Medical Herbalists, who have a code of ethics
  3. Sardesai, Vishwanath M. Herbal medicines: poisons or potions?. Journal of Laboratory & Clinical Medicine. 139(6):343-8, 2002 Jun.
  4. Bent, Stephen. Ko, Richard. Commonly used herbal medicines in the United States: a review. American Journal of Medicine. 116(7):478-85, 2004 Apr 1.
  5. About Natural Health Product Regulations; Health Canada webiste
  6. Bent, Stephen. Ko, Richard. Commonly used herbal medicines in the United States: a review. American Journal of Medicine. 116(7):478-85, 2004 Apr 1.
  7. Gagnier, Joel J. DeMelo, Jaime. Boon, Heather. Rochon, Paula. Bombardier, Claire. Quality of reporting of randomized controlled trials of herbal medicine interventions. American Journal of Medicine. 119(9):800.e1-11, 2006 Sep.
  8. Wolsko, Peter M. Solondz, David K. Phillips, Russell S. Schachter, Steven C. Eisenberg, David M. Lack of herbal supplement characterization in published randomized controlled trials. American Journal of Medicine. 118(10):1087-93, 2005 Oct.
  9. De Smet, Peter A G M. Institution. Herbal remedies. New England Journal of Medicine. 347(25):2046-56, 2002 Dec 19.
  10. http://www3.interscience.wiley.com/journal/123211007/abstract?CRETRY=1&SRETRY=0
  11. http://www.medpagetoday.com/HematologyOncology/Leukemia/17506
  12. Taibi DM, Landis CA, Petry H, Vitiello MV. "A systematic review of valerian as a sleep aid: safe but not effective." Sleep Med Rev. 2007 Jun;11(3):209-30.
  13. How Cranberry Juice Can Prevent Urinary Tract Infections, ScienceDaily, 25 July 2008
  14. Cranberry juice reduces recurrent urinary tract infection, British Medical Journal, 30 June 2001
  15. Wang Z, Gorski JC, Hamman MA, Huang SM, Lesko LJ, Hall SD. The effects of St John's wort (Hypericum perforatum) on human cytochrome P450 activity. Clin Pharmacol Ther. 2001 Oct;70(4):317-26.
  16. http://natureworksbest.com/herbalmedicine
  17. Hervé This, author of Molecular Gastronomy (or its much better French title, "Saucepans and Test Tubes") is a French research chemist who is considered the founder of molecular gastronomy as a science. He should be on your cookbook shelf right next to Corriher, Brown, Wolke, and McGee.
  18. Examples include Boltulinum Toxin, Ricin, Strychnine, Atropine, Cyanide, and Amatoxins
  19. Koretz, Ronald L. Is alternative medicine alternative science? Journal of Laboratory & Clinical Medicine. 139(6):329-33, 2002 Jun.
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