Apr 02 2018

Science and Pseudoscience of the Interstitium

Recently scientists published a study in which they present evidence for a new possible organ called the interstitium. The science here is interesting – the interstitium is a distributed system of fluid filled cavities in the connective tissue. The fluid is lymph, which means that these cavities likely play an important role in the immune system. They also give the skin and connective tissue a spongy structure, which would make them more flexible and durable.

It is also interesting how the existence of the interstitium was missed for so long. It was an artifact of the methods used to prepare tissue for slides. Fixing the tissue with chemicals would dry out the tissue, causing the cavities to collapse. It was therefore thought that these connective tissue layers were solid.

The science here seems solid, and will likely lead to further discoveries that might inform our understanding of certain diseases. However, the authors of the study decided to spread some pseudoscience along with the science.

Neil Theise, professor of pathology at NYU School of Medicine, and Rebecca Wells, professor of medicine and bioengineering at University of Pennsylvania, on a segment of Science Friday where they discuss their study, said that the interstitium might explain how acupuncture works. Some news outlets even decided to lead with the acupuncture angle. In an article for The Cut Theise digs deeper:

“Acupuncture has no anatomical correlate,” says Theise. “There’s no vein; there’s no artery; there’s no nerve corresponding to the meridian [the map of acupuncture points on the body].” Without any anatomical correlate, it’s been difficult for researchers to explain why a localized therapy like acupuncture could have such far-reaching effects. Knowing that the interstitium is filled with fluid could change that. “This is the layer of skin the acupuncture needle goes into,” says Theise. “There’s fluid in there. When you put the needle [into an accu-point], maybe the collagen bundles are arranged into a channel through which fluid can flow.” Studies show that “sham” acupuncture, or acupuncture in which needles are placed a centimeter off the meridian, doesn’t provide the same kind of pain relief that true acupuncture does: Sham accu-points may reduce pain in the immediate, local vicinity, but won’t have the widespread effects that true accu-points do. If accessing true accu-points allows interstitial fluids to travel throughout the body, that might account for the difference.

That link is to a news report of one dubious study involving carpal tunnel syndrome, “electroacupuncture” and functional MRI scanning, as if that establishes the reality of meridians and acupoints.

What is going on here is that acupuncture is one of the greatest medical scams of the last half century. The degree to which acceptance of acupuncture has penetrated into mainstream medicine, despite the double lack of plausibility and lack of credible scientific evidence, is amazing and disheartening. It reveals, in my opinion, all of the weaknesses of our current scientific infrastructure. Acupuncture, essentially, is the poster child for all the scientific flaws I write about frequently here, from p-hacking to publication bias.

In 2013 I wrote a thorough review of acupuncture, along with David Colquhoun, which I think convincingly showed through the published research that acupuncture does not work for anything. There have been several thousand studies of acupuncture, and after all that research we can make several very confident conclusions:

  • acupoints and meridians do not exist.
  • it does not matter where or even if you stick the needles
  • acupuncture is nothing more than an elaborate placebo

Since then I have kept up with the acupuncture literature and nothing has changed, except perhaps the overall quality of acupuncture studies has gotten worse. That’s right – worse. Researchers have mostly abandoned the highest quality studies, because they were frustratingly negative, and have shifted to more preliminary and practical designs that don’t really test efficacy. It seems that now they are just going for the headlines, not doing real science.

For example, I just did a search in PubMed for “acupuncture” and “review” to see what comes up. Here are relevant studies in order, without skipping any:

Acupuncture as Add-On Treatment of the Positive, Negative, and Cognitive Symptoms of Patients with Schizophrenia: A Systematic Review. 

Conclusion: “Limited evidence was found for the use of acupuncture as add-on therapy in the treatment of patients with schizophrenia; however, positive results were found in the treatment of sleep disorders, but this result needs to be confirmed in large, randomized, controlled trials.”


Acupuncture in the emergency department: a systematic review of randomised controlled trials.

Conclusion: “There is a lack of high-quality evidence to support the use of acupuncture in the ED. Multicentre RCTs with rigorous designs are warranted.”


Findings and methodological quality of systematic reviews focusing on acupuncture for pregnancy-related acute conditions.

Conclusion: “Acupuncture might be an option for alleviating pain during labour, for correcting breech presentation, and for managing pelvic and back pain during pregnancy. More studies are needed to confirm the effects of acupuncture for other pregnancy-related acute conditions.”


Risk of bias and methodological issues in randomised controlled trials of acupuncture for knee osteoarthritis: a cross-sectional study.

Conclusion: “The overall risk of bias was high among published RCTs testing acupuncture for KOA. Methodological limitations were present in many important aspects of design, conduct and analyses. These findings inform the development of evidence-based methodological guidance for future trials assessing the effect of acupuncture for KOA.”


Acupuncture for depression.

Conclusion: “The reduction in severity of depression was less when acupuncture was compared with control acupuncture than when acupuncture was compared with no treatment control, although in both cases, results were rated as providing low-quality evidence.”


After decades of doing acupuncture research we are stuck (pun intended) with wishy-washy preliminary sounding low quality evidence. Why?

Notice how many completely different conditions are allegedly treated with acupuncture. How can sticking needles in the skin reverse a breech presentation and treat schizophrenia? The idea that the existence of the interstitium adds any plausibility to this is ridiculous. That is often a red flag for quackery and pseudoscience, the panacea. It is a good rule of thumb that any treatment alleged to treat everything probably treats nothing.

That so many scientists and reporters (even science reporters) fall for the acupuncture scam relates largely to the fact that they do not understand how to truly interpret the scientific literature. In order to know if a phenomenon is real (or in medicine, that a treatment works) you have to look at the arc of the research over years.

Preliminary studies are most positive, and mostly wrong. Their purpose is just to see if something is worth pursuing with more definitive studies, and also to inform later study design. If something is real, then we would expect the positive results to hold up with more rigorous designs. The phenomenon should also lead to further discoveries pertaining to basic science, mechanism of action, etc.

Pseudosciences do not make such progress. Rather, they are stuck in the preliminary phase chasing their tails. This still generates lots of positive studies, but they tend to be low quality and high bias studies. Acupuncture is particularly prone to bias because of its cultural significance. In fact a review found that essentially 100% of acupuncture studies from China are positive. Let that sink in – that is not possible without bias, even with a treatment that actually works. The fact that Chinese acupuncture studies are 100% positive means that they are 100% unreliable, and yet they contaminate the acupuncture literature still, including the systematic reviews I linked to above.

We have had over 40 years and thousands of studies, and still researchers are unable to show that acupuncture is a real thing. The simplest explanation for this fact is that acupuncture is not a real thing. This also conforms nicely to everything we know about biology and physiology – magical meridian lines do not exist.

We can add another common feature of pseudoscience, the argument from ignorance. Every time something new is discovered, acupuncture apologists proclaim – this is the missing mechanism for acupuncture. The interstitium is just the latest claim. Of course, there is never any reason to connect the new real phenomenon with acupuncture.

Acupuncture is a perfect example of pseudoscience. The reason it has gotten so far in mainstream medicine is because its proponents are biased, and everyone else is not looking closely enough. Only those dedicated to science-based medicine seem to recognize the blatant features of pseudoscience.

It is unfortunate that an interesting study has been hijacked by pseudoscience, but in this case the authors themselves are too blame. They are tainting their own research.

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