Reviews/Commentaries/Position Statements COMMENTARY

Complementary Medicine Its hidden risks

EDZARD ERNST, MD, PHD, FRCP (EDIN) and 9% were shown to openly oppose it (13). Many doctors also worry that CM providers might interfere with their pre- scriptions, and preliminary evidence omplementary medicine (CM) is treatments can cause harm. The most ob- from the U.S. suggests that this does in- popular; 1-year prevalence figures vious indirect risk is that complementary deed happen with some regularity (14). C range from 20% in the U.K. to 65% therapies are used as true alternatives to Further indirect risks of CM relate to in Germany (1). Increasingly, CM options conventional treatments for serious med- the diagnostic methods used by some are being discussed as treatments for dia- ical conditions. Numerous examples of practitioners. For instance, chiropractors betes (2,3). The Chair of the U.S. White diabetic patients harmed by advice to al- tend to overuse X-ray diagnoses, which House Commission on CM predicted that ter their medication have been published, might unnecessarily increase the cancer “within 5–10 years CM will be part of the albeit in the form of anecdotal evidence. risk as well as costs (15). Other therapists care in every major hospital and clinic We recently encountered a nonmedically frequently use diagnostic techniques that across the country” (4), and a U.S. ‘think qualified CM practitioner who noticed a are demonstrably invalid, e.g., tank’ estimated that “by 2010 at least two- pigmented lesion on her arm and self- (16), reflexology (17), applied kinesiol- thirds (of the US population) will be using medicated with homeopathic remedies ogy (18), and electrodermal testing (19). one or more of the approaches we now without consulting her doctor, even The obvious danger here lies in false- consider complementary or alternative” though the lesion increased in size. When positive and false-negative diagnoses. In (5). Such statements implicitly suggest she was finally seen by a physician, an particular, the latter scenario can be asso- that CM is safe. In fact, a recent report by advanced malignant melanoma was diag- ciated with missing the time window for a the U.K. House of Lords’ Science and nosed; tragically, she died shortly after- possible cure of a serious condition. Technology Select Committee stated, ward. Complementary therapists assure There are even less tangible risks as- “There is no doubt that CM therapies are us that such disasters almost never hap- sociated with CM use. We recently evalu- very safe” (6). But how sure can we be that pen, but I find this hard to believe. De- ated the recommendations of some of the this is true? spite the fact that underreporting of such (several thousand) lay books on CM and Some forms of CM are clearly not to- cases is probably close to 100% and that found evidence that diabetic patients tally devoid of risk: , for in- very little systematic research exists in this could suffer real, possibly life-threatening stance, has caused deaths and other area, similar cases are reported with de- harm if they adhered to the advice issued serious complications through infection pressing regularity (8,9). in such books (20). In separate analyses, and trauma; treatment has The theme of CM hindering access to we have demonstrated that seven of the done so through vertebral arterial dissec- effective treatments is, of course, not con- leading books on CM tend to recommend tion after upper spinal manipulation; and fined to cancer or other life-threatening everything for anything, with little con- herbal medicines have caused serious conditions. Surveys from several coun- sensus among authors and even less complications through hepato- and neph- tries have suggested that a sizeable pro- grounding in reliable evidence (21). The rotoxicity as well as herb-drug interac- portion of nonmedically qualified treatments these books recommended for tions (7). Such events are almost certainly homeopaths and chiropractors advise diabetes are listed in Fig. 1; it is notable rare, but their exact incidence is unknown their clients against immunization of their that none of these are supported by evi- at present. Thus, they represent an un- children (10). Such advice is potentially dence. Collectively, these seven authors known that needs accounting for when harmful not only to the individual in recommend 133 different complemen- asking the crucial question: Does a given question (11) but, if sufficiently wide- tary treatments for cancer. Other studies CM treatment do more good than harm? spread, to entire populations. In the U.K., have shown that breast cancer patients Other complementary therapies (e.g., it represents a leading cause for noncom- frequenting health food shops are put at , , reflexology, pliance with immunization programs serious risk through the advice provided and spiritual healing) might be judged as (12). In the U.S., the majority of homeo- in such premises (22). entirely free of direct risks. Yet even these paths do not recommend immunization, ●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●●● A further intangible risk lies with the mindset of the typical CM user. Survey From the Department of Complementary Medicine, School of Postgraduate Medicine and Health Sciences, University of Exeter, Exeter, U.K. data suggests that individuals would react Address correspondence and reprint requests to E. Ernst, Department of Complementary Medicine, less cautiously when experiencing a se- School of Postgraduate Medicine and Health Sciences, University of Exeter, 25 Victoria Park Road, Exeter vere adverse effect from a herbal as com- EX2 4NT, U.K. E-mail: [email protected]. pared with a conventional over-the- Received for publication 28 March 2001 and accepted in revised form 17 April 2001. Abbreviations: CM, complementary medicine. counter medicine (23). Perhaps the least A table elsewhere in this issue shows conventional and Syste`me International (SI) units and conversion tangible and most important indirect risk factors for many substances. associated with CM is an anti-science

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4. Jobst K: There are more things in medi- cine and science than are dreamt of in our paradigm, practice and policy. J Alt Compl Med 4:295–297, 2000 5. Institute For Alternative Futures: The Future of Complementary and Alternative Approaches in US Health Care. NCMIC In- surance Company, 1998 6. Complimentary and [article online], 2000. Available from http:// www.parliament.the-stationery-office.co. uk/pa/1d199900/1dselect/1dsctech/123/ 12301.htm. Accessed May 2001 7. Ernst E: Risks associated with comple- mentary therapies. In Meyler’s Side Effects of Drugs. 14th ed. Dukes MNG, Aronson JK, Eds. Amsterdam, Holland, Elsevier Science, 2000, p. 1649–1681 8. Coppes MJ, Anderson RA, Egeler RM, Wolff JEA: Alternative therapies for the treatment of childhood cancer. N Engl J Med 339:846, 1998 9. Oneschuk D, Bruera E: The potential dan- gers of complementary therapy use in a patient with cancer. J Palliative Care 15: 49–52, 1999 10. Ernst E: Attitude against immunisation within some branches of complementary medicine. Eur J Pediatr 156:513–515, 1997 11. Delaunay P, Cua E, Lucas P, Marty P: Ho- moeopathy may not be effective in pre- venting malaria (Letter). BMJ 321:1288, 2000 12. Simpson N, Lenston S, Randall R: Poten- tial refusal to have children immunized: extent and reason. BMJ 310:227, 1995 13. Lee ACC, Kemper KJ: Homeopathy and . Arch Pediatr Adolesc Med Figure 1—Numbers in parentheses describe the frequency of recommendation; no number means 154:75–80, 2000 the treatment was only recommended once. Most of these treatments were not recommended as a 14. Moddy GA, Eaden JA, Bhakta P, Sher K, substitute for antidiabetic drugs but as adjunctive therapies. Mayberry JF: The role of complementary medicine in European and Asian patients with inflammatory bowel disease. Public attitude that sometimes emerges from en- Without it, the currently powerful move- Health 112:269–271, 1998 thusiasts of CM. Not infrequently, this ment of integrating CM into routine 15. Ernst E: Chiropractors’ use of X-rays. Br J seems to be promoted and sustained by health care seems premature and some- Radiol 71:249–251, 1998 the media. Otherwise respectable British what nonsensical. We owe it to the in- 16. Ernst E: Iridology: not useful and poten- daily newspapers, for instance, tend to re- creasing number of our patients using CM tially harmful. Arch Opthalmol 118:120– 121, 2000 port significantly more favorably about to investigate this area more seriously 17. White AR, Williamson J, Hart A, Ernst E: matters relating to CM compared with than we have done in the past—first, do A blinded investigation into the accuracy those of conventional medicine (24). Re- no harm! of reflexology. Complement Ther Med markably, the above-mentioned Lords’ 8:166–172, 2000 report on CM recognizes that “the media 18. Garrow J S: Kinesiology and food allergy. and other unregulated sources have an un- Br Med J 296:1573–1574, 1988 due influence on opinion in the field” (6). References 19. Lewith GT, Kenyon JN, Broomfield J, The bottom line of all of this is that 1. Ernst E: The role of complementary med- Prescott PH, Goddard J, Holgate ST: Is even when CM is apparently risk-free, icine. BMJ 321:1133–1135, 2000 electrodermal testing as effective as skin 2. Ernst E: Plants with hypoglycemic activity this is not necessarily true. A demonstra- prick tests for diagnosing allergies? A in humans. Phytomedicine 4:73–78, 1997 double-blind, randomised block design bly favorable risk-benefit profile is an es- 3. Namdul T, Sood A, Ramakrishnan L, Pan- study. BMJ 322:131–134, 2001 sential requirement for CM, as it is for any dey RM, Moorthy D: Efficacy of Tibetan 20. Ernst E, Armstrong NC: Lay books on other form of medicine. Without it, issues medicine as an adjunct in the treatment of complementary/alternative medicine: a like regulation of and training in CM de- type 2 diabetes (Letter). Diabetes Care 24: risk factor for good health? Int J Risk Safety grade to mere window-dressing exercises. 176–177, 2001 Med 11:209–215, 1998

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21. Ernst E, Pittler MH, Stevinson C, White cer patients. Arch Fam Med 9:692–698, face interviews with 515 users of herbal AR, Eisenberg D: The desktop guide to com- 2000 remedies. Br J Clin Pharmacol 1998: 45: plementary and alternative medicine. Lon- 23. Barnes J, Mills S, Abbot NC, Willoughby 496–500 don, Mosby, 2001 M, Ernst E: Different standards for re- 24. Ernst E, Weihmayr T: UK and German 22. Cook Gotay C, Dumitriu D: Health food porting ADRs to herbal remedies and media differ over complementary medi- store recommendations for breast can- conventional OTC medicines: face-to- cine. BMJ 321:707, 2000

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