The Placebo Effect May Not Be as Powerful as We Think

by Chris Centeno, MD /

Receive a Regenexx® Patient Info Packet by email and learn why it's a superior regenerative solution.

The entire structure of evidence-based medicine rests on the foundation of one idea, the placebo. Meaning that if a placebo treatment is not as powerful as we think, then countless high-level studies are garbage and the bedrock of modern medical science is built on quicksand. Hence, when someone publishes something about how the placebo effect may have its limitations, it should be a big deal.

What Is a Placebo?

A placebo is typically an inert, or inactive, treatment given to subjects to act as a control against an actual treatment. For example, to determine the effects of glucosamine and chondroitin on arthritis in one randomized control trial (RCT), the test group was given glucosamine and/or chondroitin while the control group was given pills that are made to look like the supplements but actually contain no glucosamine or chondroitin (i.e., the placebo). So what are the placebo treatments made from? Typically starch, saline, or some other nonmedicinal, or neutral, substance.

Surgical experiments can also involve placebo, or fake or sham, surgery. For example, one group of participants in a study, the test group, may receive the actual procedure, while a second group, the control group, receive the same approach to the surgery but not the actual surgery. A good example of this is a study I recently shared on vertebroplasty, where the test group received the vertebroplasty (the injection of bone cement into fractured backbones) and the control group only received the same approach with a simulated bone cement injection, but no actual bone cement was used.

You will often see RCTs (randomized controlled trials) described as “blind” or “double-blind,” and this simply means that the participants in either group (single-blind), and often even the investigators (double-blind), have no idea whether they are in the test group or the placebo group. Why? To key is to eliminate any potential bias in the study.

What Is a Placebo Effect?

A placebo effect is the subject’s response to the placebo treatment be it negative or positive. For example, participants who received the sham surgery (the control group) in the vertebroplasty study I mentioned above reported significant relief of their pain, almost as much relief as the vertebroplasty participants (the test group). This would be considered a placebo effect.

While some might be tempted to say the placebo effect must be all in the head, a new study may change this way of thinking. Let’s review.

How the Brain Reacts to Placebo Treatments

The neurologic pain signal (NPS) is a measure of how the brain responds to pain from a stimulus (called nociceptive pain), such as a burn, fracture, wound, and so on. Nociceptors are nerve receptors located throughout the body, and when an injury occurs, these nociceptors relay the information via our nervous system to our brain. Our brain then tells us that burn we received while pulling a casserole out of the oven hurts.

The purpose of the new study was to investigate how the brain processes pain following placebo treatments. The study, an aggregate of 20 studies consisting of over 600 participants, found that while placebo treatments moderately affect the patients’ reports of pain, there was very limited effect to the patients’ neurologic pain signal, or how the brain actually responded to nociceptive pain.

So the placebo effect is not impacting central pain states in the brain. Meaning, the placebo effect is not as powerful as previously reported, as it’s not changing how pain is registered in the brain. This means if there is a “placebo effect” type of response, the impact is likely happening elsewhere, not via the main nociceptor-brain pathway. Where? The answer to that wasn’t within the scope of this study.

The upshot? The concept of a placebo may have its limitations. Meaning, the effect isn’t changing brain activation in ways we would expect. So why the big placebo effect? First, other studies have raised questions about whether the placebo effect is significant. In addition, for some research investigations, it’s more likely the placebo is an actual therapy itself. For example, we’ve seen this in disc studies against things like platelets and stem cells. Here, it’s likely that the saline used in the disc washes away noxious chemicals, so patients report relief. Hence, the placebo effect may not be all we think. Which is a VERY, VERY big deal.

Leave a Reply

Your email address will not be published. Required fields are marked *

1 thought on “The Placebo Effect May Not Be as Powerful as We Think

  1. Sam

    Very informative! Thanks!

Chris Centeno, MD

Regenexx Founder

Chris Centeno, MD is a specialist in regenerative medicine and the new field of Interventional Orthopedics. Centeno pioneered orthopedic stem cell procedures in 2005 and is responsible for a large amount of the published research on stem cell use for orthopedic applications.
View Profile

Get Blog Updates by Email

Get fresh updates and insights from Regenexx delivered straight to your inbox.

Regenerative procedures are commonly used to treat musculoskelatal trauma, overuse injuries, and degenerative issues, including failed surgeries.
Select Your Problem Area
Shoulder

Shoulder

Many Shoulder and Rotator Cuff injuries are good candidates for regenerative treatments. Before considering shoulder arthroscopy or shoulder replacement, consider an evaluation of your condition with a regenerative treatment specialist.

  • Rotator Cuff Tears and Tendinitis
  • Shoulder Instability
  • SLAP Tear / Labral Tears
  • Shoulder Arthritis
  • Other Degenerative Conditions & Overuse Injuries
Learn More
Cervical Spine

Spine

Many spine injuries and degenerative conditions are good candidates for regenerative treatments and there are a number of studies showing promising results in treating a wide range of spine problems. Spine surgery should be a last resort for anyone, due to the cascade of negative effects it can have on the areas surrounding the surgery. And epidural steroid injections are problematic due to their long-term negative impact on bone density.

  • Herniated, Bulging, Protruding Discs
  • Degenerative Disc Disease
  • SI Joint Syndrome
  • Sciatica
  • Pinched Nerves and General Back Pain
  • And more
Learn More
Knee

Knees

Knees are the target of many common sports injuries. Sadly, they are also the target of a number of surgeries that research has frequently shown to be ineffective or minimally effective. Knee arthritis can also be a common cause for aging athletes to abandon the sports and activities they love. Regenerative procedures can be used to treat a wide range of knee injuries and conditions. They can even be used to reduce pain and delay knee replacement for more severe arthritis.

  • Knee Meniscus Tears
  • Knee ACL Tears
  • Knee Instability
  • Knee Osteoarthritis
  • Other Knee Ligaments / Tendons & Overuse Injuries
  • And more
Learn More
Lower Spine

Spine

Many spine injuries and degenerative conditions are good candidates for regenerative treatments and there are a number of studies showing promising results in treating a wide range of spine problems. Spine surgery should be a last resort for anyone, due to the cascade of negative effects it can have on the areas surrounding the surgery. And epidural steroid injections are problematic due to their long-term negative impact on bone density.

  • Herniated, Bulging, Protruding Discs
  • Degenerative Disc Disease
  • SI Joint Syndrome
  • Sciatica
  • Pinched Nerves and General Back Pain
  • And more
Learn More
Hand & Wrist

Hand & Wrist

Hand and wrist injuries and arthritis, carpal tunnel syndrome, and conditions relating to overuse of the thumb, are good candidates for regenerative treatments. Before considering surgery, consider an evaluation of your condition with a regenerative treatment specialist.
  • Hand and Wrist Arthritis
  • Carpal Tunnel Syndrome
  • Trigger Finger
  • Thumb Arthritis (Basal Joint, CMC, Gamer’s Thumb, Texting Thumb)
  • Other conditions that cause pain
Learn More
Elbow

Elbow

Most injuries of the elbow’s tendons and ligaments, as well as arthritis, can be treated non-surgically with regenerative procedures.

  • Golfer’s elbow & Tennis elbow
  • Arthritis
  • Ulnar collateral ligament wear (common in baseball pitchers)
  • And more
Learn More
Hip

Hip

Hip injuries and degenerative conditions become more common with age. Do to the nature of the joint, it’s not quite as easy to injure as a knee, but it can take a beating and pain often develops over time. Whether a hip condition is acute or degenerative, regenerative procedures can help reduce pain and may help heal injured tissue, without the complications of invasive surgical hip procedures.

  • Labral Tear
  • Hip Arthritis
  • Hip Bursitis
  • Hip Sprain, Tendonitis or Inflammation
  • Hip Instability
Learn More
Foot & Ankle

Foot & Ankle

Foot and ankle injuries are common in athletes. These injuries can often benefit from non-surgical regenerative treatments. Before considering surgery, consider an evaluation of your condition with a regenerative treatment specialist.
  • Ankle Arthritis
  • Plantar fasciitis
  • Ligament sprains or tears
  • Other conditions that cause pain
Learn More

Is Regenexx Right For You?

Request a free Regenexx Info Packet

REGENEXX WEBINARS

Learn about the #1 Stem Cell & Platelet Procedures for treating arthritis, common joint injuries & spine pain.

Join a Webinar

RECEIVE BLOG ARTICLES BY EMAIL

Get fresh updates and insights from Regenexx delivered straight to your inbox.

Subscribe to the Blog

FOLLOW US

Copyright © Regenexx 2019. All rights reserved. | Privacy Policy

*DISCLAIMER: Like all medical procedures, Regenexx® Procedures have a success and failure rate. Patient reviews and testimonials on this site should not be interpreted as a statement on the effectiveness of our treatments for anyone else.

Providers listed on the Regenexx website are for informational purposes only and are not a recommendation from Regenexx for a specific provider or a guarantee of the outcome of any treatment you receive.