Edzard Ernst’s prolific output continues. In his latest book Chiropractic: Not All That It’s Cracked Up to Be he takes on one of the most popular SCAMS (So-Called Alternative Medicines). It is an even-handed review of the history and claims of chiropractic, examining the totality of the published evidence. He addresses what he sees as “a scandalous amount of misinformation”, and tries to set the record straight. Rather than advising against chiropractic, he asks readers to make up their own minds and make reasonable decisions based on the evidence.
The book begins with this quotation from Fontanarosa and Lundberg:
There is no alternative medicine. There is only scientifically proven, evidence-based medicine supported by solid data or unproven medicine, for which scientific evidence is lacking.
He starts by describing the origin and early history of chiropractic, providing many details that were new to me. D. D. Palmer claimed to have invented it on September 18, 1895, when he adjusted the spine of deaf janitor Harvey Lillard and allegedly restored his hearing. He then extrapolated to conclude that 95% of illness was a result of displaced spinal vertebrae interfering with nerve function (the other 5% was due to subluxations of other bones). Elsewhere he claimed to have obtained his chiropractic knowledge during a séance from the ghost of a doctor. He later tried to claim that chiropractic was a religion, in an attempt to evade charges of practicing medicine without a license.
Palmer was anti-science. He claimed that smallpox was not a contagious disease but was caused by subluxations that could be corrected. He was violently anti-vaccine, a position that is perpetuated in the anti-vaccine attitudes of a majority of today’s chiropractors.
Chiropractic is said to be hugely popular, but the evidence shows that its popularity is variable and usually modest (he cites the numbers), and it is illegal in 12 countries (Argentina, Austria, Colombia, Egypt, Estonia, Greece, Hungary, Lebanon, Republic of Korea, Taiwan, Turkey, and Ukraine).
Palmer’s theories contradicted elementary anatomical facts and established scientific knowledge. The concept of a chiropractic subluxation was nebulous and doubtful (and should not be confused with an orthopedic subluxation, a painful partial dislocation of a joint which is easily viewed on an x-ray). Chiropractic subluxations are alleged bony displacements that could not be verified by x-ray, and the definition had to be changed several times. Some chiropractic schools have abandoned the term, but it remains widely accepted and is used as an excuse for chiropractors to do what they are best known for doing: spinal manipulation therapy (SMT).
SMT itself is suspect. Ernst describes the studies chiropractors have relied on to demonstrate the effectiveness of SMT and shows how they are all flawed in various ways. None of the studies controlled for placebo effects. For acute low back pain, the average patient can expect a 50/50 chance of up to a 20% improvement in pain and function, but more than 50% will report harms such as increased pain and muscle stiffness. A new drug with that risk/benefit ratio would not be approved for marketing. For chronic low back pain, the evidence shows that the treatment of choice is exercise and continued normal activity. For neck pain, the evidence is too weak to recommend SMT for routine use. One analysis showed that 31-66% of patients using chiropractic for back or neck pain also took opioids, a sad commentary on the effectiveness of chiropractic.
The majority of chiropractic visits are for back and neck pain and other musculoskeletal problems. 39% are for general wellness or disease prevention, indications that are not supported by any evidence. Chiropractors don’t live as long as medical doctors, or even as long as the general population. D. D. Palmer claimed that chiropractors could treat bunions, syphilis, peritonitis, cholera, strokes, and many other diverse conditions and could even “correct abnormalities of the intellect”. Today, some chiropractors use SMT for non-musculoskeletal conditions where SMT is not evidence-based or even plausible, such as ear infections, asthma, and infertility. 42% of UK chiropractors believe SMT is effective for high blood pressure; the evidence shows that it isn’t. Today’s chiropractors use a variety of adjustment techniques that have never been compared to each other or even tested for efficacy. 39% of US chiropractors treat children; skeptical chiropractor Samuel Homola calls that child abuse.
One chapter covers bogus alternative therapies and diagnostic procedures that have been adopted by many chiropractors, including homeopathy, acupuncture, cupping, applied kinesiology, electrodermal testing machines like Vega Test, energy healing, detox, chelation, and untested dietary supplements.
Adverse effects of treatment are not mentioned or are under-reported in the chiropractic literature. The most reliable data show that 50% or more of patients experience adverse effects. In Finland, adverse events were reported by 81% of women and 66% of men.
Does SMT cause strokes? Ernst devotes a whole chapter to that question. His assessment is fair. He describes the evidence and admits that questions remain and that the risk can’t be quantified. But the circumstantial evidence is worrisome, to say the least; and since the benefit is small to nonexistent, the risk of SMT, especially of neck manipulation, is hard to justify.
Ernst covers ethical considerations, what constitutes true informed consent, and the risk of indirect harms in addition to direct harms. He explains what constitutes good evidence. He discusses the poor quality of most chiropractic research, including frequent use of trials that compare standard treatment alone to standard treatment plus SMT, a design that is guaranteed to make SMT look better than it is.
The book is published by Springer Nature Switzerland. They did not serve Ernst well. Every two pages were attached together along the outer edge, prepared for easy separation but requiring the reader to do the separating in order to read the book. And there were many typos that should have been caught by any competent proofreader. For example, the country Colombia is mis-spelled “Columbia”. And a 4-item list of complications lists “spastic quadriparesis” twice.
Conclusion: An excellent reference
This book is an excellent, comprehensive reference for all things chiropractic. It provides solid facts to correct widespread misinformation. It provides evidence that should answer any question a reader might come up with. It doesn’t tell readers what to think, but it provides the tools to help them think clearly for themselves. Thank you, Edzard, for once again sharing your wisdom, knowledge, and experience with the world.
This article was originally published in the Science-Based Medicine Blog.