As I traveled the country lecturing about the evidence-based principles of chiropractic care, it quickly dawned on me: The chiropractic research has been portrayed in a distorted, biased way. Heavy on one side, and woefully light on the other, if the current paradigm continues, the world will think that chiropractors are only able to help with headaches and back pain, though nothing could be further from the truth.
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Chiropractic Research “Proving” Health Benefits
Two Internet marketing service companies, ChiroHosting and ChiroNexus, published a follow-up to their very popular Top 10 Chiropractic Studies of 2013 with a new 2014 edition. According to their team, the Top 12 Chiropractic Studies of 2014 were: (1)
- Chiropractic Adjustments Boost Antioxidant Levels (2)
- Chiropractic Care Keeps Seniors Mobile and Active (3)
- Chiropractic is Safe and Effective for Back Pain During Pregnancy (4)
- Chiropractic Reduces Herniated Disc Pain (5)
- Chiropractic Eases Back-Related Leg Pain (6)
- Benefits of On-Site Chiropractic Care for Workers (7)
- Spinal Manipulation Alters Pain and Stress Hormones (8)
- Chiropractic Less Expensive than Medical Care
- Chiropractic Safer than Medical Care for Elderly (9)
- Chiropractic Effective for Patients with Spinal Degeneration (10)
- Chiropractic Relieves Neck Pain in Senior Citizens (11)
- Chiropractic Helps Athletes Jump Higher After Ankle Injury (12)
This is an interesting list … but I have a slight problem with it.
Dr. B.J Hardick (13) puts it best, “The problem that I have with the 2014 list – as well as the 2013 Top 10 – is that it is unusually biased in its presentation.”
Besides three studies – one discussing the cost-effectiveness of chiropractic, one about the potential immune boosting capability of a specific adjustment, and one concerning the enhancement in athletic performance after an ankle injury – all of these studies are musculoskeletal based.
I must admit that a great number patients come into chiropractors’ offices with neck and back complaints. And, yes, DCs regularly help them live a pain free life, but that’s just the gateway experience for most patients. The fascinating thing about chiropractic care is the wonderful testimonials that come from people who suffer from “seemingly unrelated” complaints that spontaneously resolve after getting adjusted.
Because DCs see these results day in and day out, these experiences are the basis for my personal Top 10 List of Chiropractic Research Studies.
A Note About Anecdotal Evidence
Oftentimes criticized as not being true science, case studies and personal testimonials are referred to as “anecdotal evidence,” and naturally, many in the research field stick their noses up in the air to the “chiropractic miracles” in research journals. Granted, a case study is not a rigorous piece of research as a 20-year long cohort study, but it does have merit. (Just ask the person whose life was changed!)
Before I list my Top 10 chiropractic studies of all time, we need to call out the elephant in the room. Being a profession based on non-surgical and non-pharmaceutical protocols, the funding for chiropractic studies is greatly lacking. The majority of the research done in the medical community is funded by pharmaceutical companies.
Because of this, most of the chiropractic research has been restricted to case studies and editorials/theory papers. Although, a fair number of clinical trials have been performed, it should come as no surprise that drug companies do not fund a lot of chiropractic studies.
Epidemiology 101 teaches Public Health students that case studies are a vital part of the research pyramid. It’s really all about justifying the necessity and safety of approving a particular intervention. In response to the horrible Nazi and Tuskegee syphilis experiments, the entire discipline of bioethics was birthed.
To prevent any more atrocities to human research subjects, the National Institute of Health requires that a governing body – known as the Institutional Review Board (IRB) – from a university, non-profit or research-oriented organization “approve” a study; basically, verifying that it is a safe and worthwhile project to perform on people.
In most “evidence pyramids” you see research ranked as follows (with 1 being the top of the pyramid): (14)
- Systematic Reviews – a rigorous, systemic approach to evaluate ALL the relevant data on a particular study.
- Randomized Control Trials – experimental studies referred to as the “gold standard” of research where the test subject and/or the person perform the test is blinded to the details of the intervention (e.g. a medication) to prevent bias.
- Cohort Studies – observational studies where a group of people without a disease is evaluated over time until a particular disease or outcome of interest occurs.
- Case Studies – a much quicker study where a group of people already with a disease is questioned to determine what may have caused the illness.
- Case Reports – a write up of an individual person’s experience with a disease or invention. They are referred to as “anecdotal evidence” because they are simply stories that are subject to bias and misrepresentation.
- Editorials, Expert Opinions – papers written with the purpose of sharing one’s knowledge of the scientific literature or experience in a clinical setting to shed light on a particular topic.
- Animal Studies – studies performed on mammals with the intention to test overall mammalian safety.
- In Vitro Studies – test tube studies where human or animal cells are tested in a petri dish to get a baseline level of understanding of how an intervention may affect the body.
Before we discard something valuable along with something not wanted, let’s give credit where credit is due, and elevate case studies to their rightful spot on the research hierarchy.
Having said that, here’s my list:
My Top 10 Chiropractic Research Papers
It was a REAL challenge to narrow down all my favorite research chiropractic studies to just 10, but this list does my beloved profession well-deserved justice.
1. Chiropractic adjustment has the same effect as two blood pressure lowering medications.
Published in the world-renown Journal of Human Hypertension (15) in 2007, the landmark study finally proved what tens of thousands of patients have experienced for 100 years: gentle, specific upper cervical chiropractic adjustments can lower blood pressure! (16)
The double blind, placebo-controlled study took 50 patients with Stage 1 hypertension who were never exposed to blood pressure medication and randomized them into two groups: one to receive a National Upper Cervical Chiropractic (NUCCA) chiropractic adjustment, and one to receive a sham procedure. After just one adjustment, the patient’s systolic blood pressure was evaluated over a course of time, and the researchers discovered that a 17-point drop was sustained after 8 weeks.
2. Chiropractic adjustments can normalize blood pressure BOTH ways.
In 2012, the Journal of Upper Cervical Chiropractic Research reported the results of a study that took 42 patients and recorded arterial blood pressure (ABP) for the following groups: Hypotensive, Normotensive, Pre-Hypertensive, Stage One Hypertensive, and Stage Two Hypertensive. Fascinatingly, “Pre-Hypertensive, Stage One Hypertensive, and Stage Two Hypertensive groups had a statistically significant decrease in ABP.
There was an increase in ABP in the Hypotensive group” as well. Thus showing how “realignment of the atlas does not simply lower ABP, but may also be part of a systemic homeostatic mechanism not yet completely understood. The same adjustment that decreased hypertensive ABP measurements also increased hypotensive ABP measurements to more normal levels.” (17)
3. Chiropractic adjustments can help children with autism.
A case study published in the Annals of Vertebral Subluxation in 2013 outlined a most fascinating case of how simple spinal correction can help peel away the onion of a child suffering from autism and related symptoms one layer at a time. (18) In the case, a 3-year old girl suffered from:
- Acid reflux
- Being birthed by a mother under the influence of narcotics
- Intermittent headache
- Premature birth
After a course of chiropractic visits, the little girl started to improve literally one symptom at a time. First the headaches vanished, then the seizures. After a while, the acid reflex subsided, which helped with vomiting and sleeplessness. Last of all, the mental and emotional challenges she experienced with autism systematically went away. This little girl, completely unable to speak at the age of 3 and averse to making eye contact with people, uttered “Mama” for the first time and gave her adopted parents hope that she could live a “normal” life!
Kids respond well to chiropractic care, and it is safe for children of all ages.
4. Chiropractic adjustments help HIV/AIDS patients.
This study is a classic from the late chiropractic researcher Dr. John D. Grostic. Completed in 1994, Dr. Grostic and his team of Life University researchers evaluated CD4 counts (a type of white blood cell that fights infection ad is a measure of how strong the immune system is) in HIV/AIDS patients before and after chiropractic adjustments and discovered that they were increased once vertebral subluxations were corrected. (19)
A subluxation, defined as neurological interference due to a misalignment in the spinal column, has widespread effects on the human body as a result of the spinal structure’s influence over the function of the nerves which extend from it to organs of the body. Like this study suggests, organ function can and will be affected if the nervous system is impeded in any way.
5. Models of vertebral subluxation.
Any Top 10 list of chiropractic studies has to include something by Dr. Christopher Kent, Esq. I have known Dr. Kent for 10 years, and admired and followed his work since I was in undergrad. Dr. Kent is arguably the most brilliant mind in the profession today and, although isn’t a “researcher” in a lab-coat-evaluating-petri-dishes kind of way, he has been a thought-leader in developing theories and expert opinions in the profession for decades. I could have chosen any one of Dr. Kent’s editorials to be included in my list, but I have to go with his classic, “Models of vertebral subluxation: A review.” (20)
In this 1996 paper, Dr. Kent outlines in his characteristically eloquent and ingenious way the various ways that vertebral subluxations can be hazardous to our health. As Dr. Kent points out,
“As a consequence, biomechanical dysfunction [of the spine] may result in an alteration in normal nociception and/or mechanoreception. Aberrated afferent input to the CNS may lead to dysponesis. To use the contemporary jargon of the computer industry, ‘garbage in—garbage out.’ Appreciation of these processes begins with an understanding of the neuroanatomy of the tissues of the intervertebral motion segment.”
Simple as that.
6. Objective instrumentation to test for vertebral subluxation proven reliable and effective.
In 2011, PloS One published what may be the most important clinical trial to support the effectiveness of paraspinal thermography, a tool that chiropractors use every day to substantiate the presence and removal of a vertebral subluxation. (21)
According to the researchers who conducted the inter- and intra-reliability study:
“Alterations in skin temperature patterns are thought to be associated with aberrations in the function of the sympathetic nervous system innervating the skin vascular beds. Autonomic nervous system control of the organs, glands, and blood vessels is responsible for thermoregulatory control of the person to the dynamics of the outside world. When the outside environment is cool, the body will attempt to conserve heat, resulting in constriction of the arterioles in the skin. Conversely, when the outside environment is hot, the body seeks to eliminate heat through vasodilation of the arterioles in the skin.
Thermal readings have been used to detect right-left differences in paraspinal skin temperature since the 1920’s.
The theory is that in a healthy patient, skin temperature patterns will change with thermoregulatory control but remain symmetrical across body regions as the body adapts to the environment. For clinicians managing spinal disorders it is argued that segmental or global distortions result in thermal right-left asymmetries and certain fixed patterns may exist as a result.” (11)
Personally, I can attest to this, having studied thermography for over a decade. It is one of the most objective tools that we have in the profession for testing purposes.
7. Seventy-five year old research archives.
Not just because he’s my eponym, but the 1998 article about “The Resurrection of the B.J. Palmer Clinic Research” highlights just how innovated and profound early chiropractic research was. (22) What Dr. Palmer did back in the early to mid 20th century was truly well ahead of its time.
8-10. Chiropractic boosts immune activity.
Like we saw with the HIV/AIDS patients study above, removing neurological interference from the human body can have dramatic effects on the immune systems of all sorts of ill and healthy people. These studies show just how widespread this can be. If you’ve ever heard that going to a chiropractor will help you from getting sick, or assist with health during flu season, this is why:
- Enhance production of immunoregulatory cytokine IL-2 and the production of immunoglobulins. (23, 24)
- Promote the production of white blood cells. (25, 26)
- Reduce the production of pro-inflammatory cytokines. (27)
My list of the Top 10 Chiropractic Research Papers, a solid combination of clinical trials and case studies, in addition to historical and theoretical papers, paints a beautiful picture of the extensive advantages people will continue to receive at the hands of chiropractors around the world for years to come.