The tour of the sausage factory is starting, here’s your brochure telling you’ll see.
A recent review has received a lot of attention with it being used for claims that mind-body interventions have distinct molecular signatures that point to potentially dramatic health benefits for those who take up these practices.
What Is the Molecular Signature of Mind–Body Interventions? A Systematic Review of Gene Expression Changes Induced by Meditation and Related Practices. Frontiers in Immunology. 2017;8.
Few who are tweeting about this review or its press coverage are likely to have read it or to understand it, if they read it. Most of the new agey coverage in social media does nothing more than echo or amplify the message of the review’s press release. Lazy journalists and bloggers can simply pass on direct quotes from the lead author or even just the press release’s title, ‘Meditation and yoga can ‘reverse’ DNA reactions which cause stress, new study suggests’:
“These activities are leaving what we call a molecular signature in our cells, which reverses the effect that stress or anxiety would have on the body by changing how our genes are expressed.”
“Millions of people around the world already enjoy the health benefits of mind-body interventions like yoga or meditation, but what they perhaps don’t realise is that these benefits begin at a molecular level and can change the way our genetic code goes about its business.”
[The authors of this review actually identified some serious shortcomings to the studies they reviewed. I’ll be getting to some excellent points at the end of this post that run quite counter to the hype. But the lead author’s press release emphasized unwarranted positive conclusions about the health benefits of these practices. That is what is most popular in media coverage, especially from those who have stuff to sell.]
Interpretation of the press release and review authors’ claims requires going back to the original studies, which most enthusiasts are unlikely to do. If readers do go back, they will have trouble interpreting some of the deceptive claims that are made.
Yet, a lot is at stake. This review is being used to recommend mind-body interventions for people having or who are at risk of serious health problems. In particular, unfounded claims that yoga and mindfulness can increase the survival of cancer patients are sometimes hinted at, but occasionally made outright.
This blog post is written with the intent of protecting consumers from such false claims and providing tools so they can spot pseudoscience for themselves.
Discussion in the media of the review speaks broadly of alternative and complementary interventions. The coverage is aimed at inspiring confidence in this broad range of treatments and to encourage people who are facing health crises investing time and money in outright quackery. Seemingly benign recommendations for yoga, tai chi, and mindfulness (after all, what’s the harm?) often become the entry point to more dubious and expensive treatments that substitute for established treatments. Once they are drawn to centers for integrative health care for classes, cancer patients are likely to spend hundreds or even thousands on other products and services that are unlikely to benefit them. One study reported:
More than 72 oral or topical, nutritional, botanical, fungal and bacterial-based medicines were prescribed to the cohort during their first year of IO care…Costs ranged from $1594/year for early-stage breast cancer to $6200/year for stage 4 breast cancer patients. Of the total amount billed for IO care for 1 year for breast cancer patients, 21% was out-of-pocket.
Coming up, I will take a skeptical look at the six randomized trials that were highlighted by this review. But in this post, I will provide you with some tools and insights so that you do not have to make such an effort in order to make an informed decision.
Like many of the other studies cited in the review, these randomized trials were quite small and underpowered. But I will focus on the six because they are as good as it gets. Randomized trials are considered a higher form of evidence than simple observational studies or case reports [It is too bad the authors of the review don’t even highlight what studies are randomized trials. They are lumped with others as “longitudinal studies.]
As a group, the six studies do not actually add any credibility to the claims that mind-body interventions – specifically yoga, tai chi, and mindfulness training or retreats improve health by altering DNA. We can be no more confident with what the trials provide than we would be without them ever having been done.
I found the task of probing and interpreting the studies quite labor-intensive and ultimately unrewarding.
I had to get past poor reporting of what was actually done in the trials, to which patients, and with what results. My task often involved seeing through cover ups with authors exercising considerable flexibility in reporting what measures were they actually collected and what analyses were attempted, before arriving at the best possible tale of the wondrous effects of these interventions.
Interpreting clinical trials should not be so hard, because they should be honestly and transparently reported and have a registered protocol and stick to it. These reports of trials were sorely lacking, The full extent of the problems took some digging to uncover, but some things emerged before I got to the methods and results.
The introductions of these studies consistently exaggerated the strength of existing evidence for the effects of these interventions on health, even while somehow coming to the conclusion that this particular study was urgently needed and it might even be the “first ever”. The introductions to the six papers typically cross-referenced each other, without giving any indication of how poor quality the evidence was from the other papers. What a mutual admiration society these authors are.
One giveaway is how the introductions referred to the biggest, most badass, comprehensive and well-done review, that of Goyal and colleagues.
That review clearly states that the evidence for the effects of mindfulness is poor quality because of the lack of comparisons with credible active treatments. The typical randomized trial of mindfulness involves a comparison with no-treatment, a waiting list, or patients remaining in routine care where the target problem is likely to be ignored. If we depend on the bulk of the existing literature, we cannot rule out the likelihood that any apparent benefits of mindfulness are due to having more positive expectations, attention, and support over simply getting nothing. Only a handful of hundreds of trials of mindfulness include appropriate, active treatment comparison/control groups. The results of those studies are not encouraging.
One of the first things I do in probing the introduction of a study claiming health benefits for mindfulness is see how they deal with the Goyal et al review. Did the study cite it, and if so, how accurately? How did the authors deal with its message, which undermines claims of the uniqueness or specificity of any benefits to practicing mindfulness?
For yoga, we cannot yet rule out that it is better than regular exercising – in groups or alone – having relaxing routines. The literature concerning tai chi is even smaller and poorer quality, but there is the same need to show that practicing tai chi has any benefits over exercising in groups with comparable positive expectations and support.
Even more than mindfulness, yoga and tai chi attract a lot of pseudoscientific mumbo jumbo about integrating Eastern wisdom and Western science. We need to look past that and insist on evidence.
Like their introductions, the discussion sections of these articles are quite prone to exaggerating how strong and consistent the evidence is from existing studies. The discussion sections cherry pick positive findings in the existing literature, sometimes recklessly distorting them. The authors then discuss how their own positively spun findings fit with what is already known, while minimizing or outright neglecting discussion of any of their negative findings. I was not surprised to see one trial of mindfulness for cancer patients obtain no effects on depressive symptoms or perceived stress, but then go on to explain mindfulness might powerfully affect the expression of DNA.
If you want to dig into the details of these studies, the going can get rough and the yield for doing a lot of mental labor is low. For instance, these studies involved drawing blood and analyzing gene expression. Readers will inevitably encounter passages like:
In response to KKM treatment, 68 genes were found to be differentially expressed (19 up-regulated, 49 down-regulated) after adjusting for potentially confounded differences in sex, illness burden, and BMI. Up-regulated genes included immunoglobulin-related transcripts. Down-regulated transcripts included pro-inflammatory cytokines and activation-related immediate-early genes. Transcript origin analyses identified plasmacytoid dendritic cells and B lymphocytes as the primary cellular context of these transcriptional alterations (both p < .001). Promoter-based bioinformatic analysis implicated reduced NF-κB signaling and increased activity of IRF1 in structuring those effects (both p < .05).
Intimidated? Before you defer to the “experts” doing these studies, I will show you some things I noticed in the six studies and how you can debunk the relevance of these studies for promoting health and dealing with illness. Actually, I will show that even if these 6 studies got the results that the authors claimed- and they did not- at best, the effects would trivial and lost among the other things going on in patients’ lives.
Fortunately, there are lots of signs that you can dismiss such studies and go on to something more useful, if you know what to look for.
Some general rules:
- Don’t accept claims of efficacy/effectiveness based on underpowered randomized trials. Dismiss them. The rule of thumb is reliable to dismiss trials that have less than 35 patients in the smallest group. Over half the time, true moderate sized effects will be missed in such studies, even if they are actually there.
Due to publication bias, most of the positive effects that are published from such sized trials will be false positives and won’t hold up in well-designed, larger trials.
When significant positive effects from such trials are reported in published papers, they have to be large to have reached significance. If not outright false, these effect sizes won’t be matched in larger trials. So, significant, positive effect sizes from small trials are likely to be false positives and exaggerated and probably won’t replicate. For that reason, we can consider small studies to be pilot or feasibility studies, but not as providing estimates of how large an effect size we should expect from a larger study. Investigators do it all the time, but they should not: They do power calculations estimating how many patients they need for a larger trial from results of such small studies. No, no, no!
Having spent decades examining clinical trials, I am generally comfortable dismissing effect sizes that come from trials with less than 35 patients in the smaller group. I agree with a suggestion that if there are two larger trials are available in a given literature, go with those and ignore the smaller studies. If there are not at least two larger studies, keep the jury out on whether there is a significant effect.
Applying the Rule of 35, 5 of the 6 trials can be dismissed and the sixth is ambiguous because of loss of patients to follow up. If promoters of mind-body interventions want to convince us that they have beneficial effects on physical health by conducting trials like these, they have to do better. None of the individual trials should increase our confidence in their claims. Collectively, the trials collapse in a mess without providing a single credible estimate of effect size. This attests to the poor quality of evidence and disrespect for methodology that characterizes this literature.
- Don’t be taken in by titles to peer-reviewed articles that are themselves an announcement that these interventions work. Titles may not be telling the truth.
What I found extraordinary is that five of the six randomized trials had a title that indicating a positive effect was found. I suspect that most people encountering the title will not actually go on to read the study. So, they will be left with the false impression that positive results were indeed obtained. It’s quite a clever trick to make the title of an article, by which most people will remember it, into a false advertisement for what was actually found.
For a start, we can simply remind ourselves that with these underpowered studies, investigators should not even be making claims about efficacy/effectiveness. So, one trick of the developing skeptic is to confirm that the claims being made in the title don’t fit with the size of the study. However, actually going to the results section one can find other evidence of discrepancies between what was found in what is being claimed.
I think it’s a general rule of thumb that we should be careful of titles for reports of randomized that declare results. Even when what is claimed in the title fits with the actual results, it often creates the illusion of a greater consistency with what already exists in the literature. Furthermore, even when future studies inevitably fail to replicate what is claimed in the title, the false claim lives on, because failing to replicate key findings is almost never a condition for retracting a paper.
- Check the institutional affiliations of the authors. These 6 trials serve as a depressing reminder that we can’t go on researchers’ institutional affiliation or having federal grants to reassure us of the validity of their claims. These authors are not from Quack-Quack University and they get funding for their research.
In all cases, the investigators had excellent university affiliations, mostly in California. Most studies were conducted with some form of funding, often federal grants. A quick check of Google would reveal from at least one of the authors on a study, usually more, had federal funding.
- Check the conflicts of interest, but don’t expect the declarations to be informative. But be skeptical of what you find. It is also disappointing that a check of conflict of interest statements for these articles would be unlikely to arouse the suspicion that the results that were claimed might have been influenced by financial interests. One cannot readily see that the studies were generally done settings promoting alternative, unproven treatments that would benefit from the publicity generated from the studies. One cannot see that some of the authors have lucrative book contracts and speaking tours that require making claims for dramatic effects of mind-body treatments could not possibly be supported by: transparent reporting of the results of these studies. As we will see, one of the studies was actually conducted in collaboration with Deepak Chopra and with money from his institution. That would definitely raise flags in the skeptic community. But the dubious tie might be missed by patients in their families vulnerable to unwarranted claims and unrealistic expectations of what can be obtained outside of conventional medicine, like chemotherapy, surgery, and pharmaceuticals.
Based on what I found probing these six trials, I can suggest some further rules of thumb. (1) Don’t assume for articles about health effects of alternative treatments that all relevant conflicts of interest are disclosed. Check the setting in which the study was conducted and whether it was in an integrative [complementary and alternative, meaning mostly unproven.] care setting was used for recruiting or running the trial. Not only would this represent potential bias on the part of the authors, it would represent selection bias in recruitment of patients and their responsiveness to placebo effects consistent with the marketing themes of these settings.(2) Google authors and see if they have lucrative pop psychology book contracts, Ted talks, or speaking gigs at positive psychology or complementary and alternative medicine gatherings. None of these lucrative activities are typically expected to be disclosed as conflicts of interest, but all require making strong claims that are not supported by available data. Such rewards are perverse incentives for authors to distort and exaggerate positive findings and to suppress negative findings in peer-reviewed reports of clinical trials. (3) Check and see if known quacks have prepared recruitment videos for the study, informing patients what will be found (Serious, I was tipped off to look and I found that).
- Look for the usual suspects. A surprisingly small, tight, interconnected group is generating this research. You could look the authors up on Google or Google Scholar or browse through my previous blog posts and see what I have said about them. As I will point out in my next blog, one got withering criticism for her claim that drinking carbonated sodas but not sweetened fruit drinks shortened your telomeres so that drinking soda was worse than smoking. My colleagues and I re-analyzed the data of another of the authors. We found contrary to what he claimed, that pursuing meaning, rather than pleasure in your life, affected gene expression related to immune function. We also showed that substituting randomly generated data worked as well as what he got from blood samples in replicating his original results. I don’t think it is ad hominem to point out a history for both of the authors of making implausible claims. It speaks to source credibility.
- Check and see if there is a trial registration for a study, but don’t stop there. You can quickly check with PubMed if a report of a randomized trial is registered. Trial registration is intended to ensure that investigators commit themselves to a primary outcome or maybe two and whether that is what they emphasized in their paper. You can then check to see if what is said in the report of the trial fits with what was promised in the protocol. Unfortunately, I could find only one of these was registered. The trial registration was vague on what outcome variables would be assessed and did not mention the outcome emphasized in the published paper (!). The registration also said the sample would be larger than what was reported in the published study. When researchers have difficulty in recruitment, their study is often compromised in other ways. I’ll show how this study was compromised.
Well, it looks like applying these generally useful rules of thumb is not always so easy with these studies. I think the small sample size across all of the studies would be enough to decide this research has yet to yield meaningful results and certainly does not support the claims that are being made.
But readers who are motivated to put in the time of probing deeper come up with strong signs of p-hacking and questionable research practices.
- Check the report of the randomized trial and see if you can find any declaration of one or two primary outcomes and a limited number of secondary outcomes. What you will find instead is that the studies always have more outcome variables than patients receiving these interventions. The opportunities for cherry picking positive findings and discarding the rest are huge, especially because it is so hard to assess what data were collected but not reported.
- Check and see if you can find tables of unadjusted primary and secondary outcomes. Honest and transparent reporting involves giving readers a look at simple statistics so they can decide if results are meaningful. For instance, if effects on stress and depressive symptoms are claimed, are the results impressive and clinically relevant? Almost in all cases, there is no peeking allowed. Instead, authors provide analyses and statistics with lots of adjustments made. They break lots of rules in doing so, especially with such a small sample. These authors are virtually assured to get results to crow about.
Famously, Joe Simmons and Leif Nelson hilariously published claims that briefly listening to the Beatles’ “When I’m 64” left students a year and a half older younger than if they were assigned to listening to “Kalimba.” Simmons and Leif Nelson knew this was nonsense, but their intent was to show what researchers can do if they have free reign with how they analyze their data and what they report and . They revealed the tricks they used, but they were so minor league and amateurish compared to what the authors of these trials consistently did in claiming that yoga, tai chi, and mindfulness modified expression of DNA.
Stay tuned for my next blog post where I go through the six studies. But consider this, if you or a loved one have to make an immediate decision about whether to plunge into the world of woo woo unproven medicine in hopes of altering DNA expression. I will show the authors of these studies did not get the results they claimed. But who should care if they did? Effects were laughably trivial. As the authors of this review about which I have been complaining noted:
One other problem to consider are the various environmental and lifestyle factors that may change gene expression in similar ways to MBIs [Mind-Body Interventions]. For example, similar differences can be observed when analyzing gene expression from peripheral blood mononuclear cells (PBMCs) after exercise. Although at first there is an increase in the expression of pro-inflammatory genes due to regeneration of muscles after exercise, the long-term effects show a decrease in the expression of pro-inflammatory genes (55). In fact, 44% of interventions in this systematic review included a physical component, thus making it very difficult, if not impossible, to discern between the effects of MBIs from the effects of exercise. Similarly, food can contribute to inflammation. Diets rich in saturated fats are associated with pro-inflammatory gene expression profile, which is commonly observed in obese people (56). On the other hand, consuming some foods might reduce inflammatory gene expression, e.g., drinking 1 l of blueberry and grape juice daily for 4 weeks changes the expression of the genes related to apoptosis, immune response, cell adhesion, and lipid metabolism (57). Similarly, a diet rich in vegetables, fruits, fish, and unsaturated fats is associated with anti-inflammatory gene profile, while the opposite has been found for Western diet consisting of saturated fats, sugars, and refined food products (58). Similar changes have been observed in older adults after just one Mediterranean diet meal (59) or in healthy adults after consuming 250 ml of red wine (60) or 50 ml of olive oil (61). However, in spite of this literature, only two of the studies we reviewed tested if the MBIs had any influence on lifestyle (e.g., sleep, diet, and exercise) that may have explained gene expression changes.
How about taking tango lessons instead? You would at least learn dance steps, get exercise, and decrease any social isolation. And so what if there were more benefits than taking up these other activities?