Yoga May Slow Age-Related Changes in Healthy Adult Men

by Baxter

The Three Ages of Men by Giorgione

I am always excited to have good news to share with my male students about how yoga can improve their health, and when recently I learned about a study done in India that looked at yoga’s potential beneficial effects on aging for healthy men, I decided to check it out! I first read about the study “Age-related changes in cardiovascular system, autonomic functions, and levels of BDNF of healthy active males: role of yogic practice” on a web site. (I’ll get to what BDNF is in minute!) The web site discussed the findings of the study, but only positive information about the study presented and there was no mention of any limitations of how the study was done or whether its design would allow for us to draw comparisons to large groups of adults doing yoga. To me, this was a bit of a red flag. On the one hand, I was excited to see a study done that was checking blood chemicals, EKGs, and other signs of stress related to aging. Because I wanted to know more about the study, such as the actual number of participants and how long they were followed and if there was any long term follow up, I went the source, the actual paper itself. (Although you can’t access the paper yourself, you can find the abstract here.)

The first sentences of the abstract for the study gave me a good starting point on why the researchers were doing the paper. My translations of the scientific language into more accessible terms are in brackets.

“Aging is associated with decline in cardiovascular, autonomic function, and brain-derived neurotropic factor (BDNF). [this is what we know from present research on aging] Reports are scanty regarding whether yoga can improve age-related degenerative changes in healthy active men. [this is what we don’t know yet] This study is designed to appraise the role of yoga in improving age-related degenerative changes in cardio-metabolic risk profile, autonomic function, stress, and BDNF. [this is what scientists plan to look at] 

And I have to say that these researchers checked a lot of stuff in the participants to assess their goals—quite impressive! But how did they choose the men in the study? These were their criteria:

“Inclusion criteria included (1) normal healthy and physically active male; (2) absence of disease which could have contributed to obesity, hypertension, and neurological disorders; (3) not on medication; (4) no prior knowledge of yoga; and (5) smokers, alcoholics, and tobacco eaters (in India, where the study was done, they eat tobacco!) were excluded from study.” 

This seems reasonable: healthy, active men who have not done yoga before. However, one immediate problem was the small number of men in the study, only 60 in total. The authors looked at three groups of healthy men, 20 in each group, with age ranges of 20-29, 30-39, and 40-49. This is a concern because the smaller the numbers of participants, the less compelling the results of any study are. 

In studying this group, the scientists checked a variety of data related to aging, including blood tests for quite a number of markers, such as cortisol, and a brain substance called BDNF, or brain-derived neurotropic factor, which normally drops as we age. (BDNF is a key mediator of neuronal plasticity in adult, adult neurogenesis, and brain aging.) “Blood samples were collected in the morning after overnight fasting before and after 3 months yogic practice for biochemical estimation.” And the results are quite encouraging! Heart-, metabolic-, and neurologic-related aging changes were better in their study group.

So how much yoga and what kind of practices were these men doing? I was curious about what the yoga practice looked like: was it a simple beginner practice, and was it well rounded in poses, breath work and meditation?

According to the paper, “In addition to their routine activities, participants practiced one hour of yoga for 3 months in the morning with ambient temperature under supervision of qualified yoga instructor.” And here is what they did:

Table 2 Details of yogic module

Cleansing processes (2 min)

Kapalbhati (Rapid shallow breathing) 

Yogasanas (yogic postures): Total of 40 minutes

Suryanamaskar (sun salutation in 12 different postures, 1 round)

Padmasana 

Yogamudra

Matsayasana

Suptapavanmuktasana

Pavanmuktasana

Paschimottanasana

Vajrasana

Suptavajrasana

Gomukhasana

Sarvangasana

Halasana

Karnapedasana

Bhujangasana

Shavasana (relaxed supine posture)

Pranayama (breathing exercises): Total of 10 minutes

Bhastrika (forceful expulsion of breathing)

Anulom-vilom (alternative nostril breathing)

Bhramri (producing buzzing sound of bee with closed ear and lips)

Meditation: Total of 8 minutes

Omkar meditation (Om Chant)

Total session 60 minutes.

Although this protocol includes poses, breath work and meditation—a good balance—I’m concerned about the poses they practices, which are all symmetrical poses and are either forward bends or backbends, with no twists or side bends included. And many of the poses are intermediate ones, which someone unfamiliar with yoga might have trouble with, such as full Lotus, Shoulderstand and variations, and Reclined Thunderbolt pose, to name the most obvious. This could limit the applicability of this particular practice for the general population. 

To their credit, the authors do cite some of the limitations of the study, including the lack of control group (a control group is a similar number of healthy active men that did not do yoga and were evaluated with the same tests-this study does not have one): 

“The present study suffers from some limitations that need to be acknowledged and addressed. One of these is the relatively small sample size in each group. An additional limitation is that this study is a single-arm study without any separate control group.” 

And their final conclusion is also fairly accurate: 

“Based on the results of the present study, it may be concluded that the aging process has an active role on degenerative changes in cardio-metabolic risk factors, autonomic functions, and monoamines as well as levels of BDNF, which may revert back towards normal or near-normal levels through yogic practice in healthy active males. (bold is mine)” 

But the limitation that they did not mention is that we only know what the effect was at the end of three months of practice. We don’t know if these beneficial findings would be persistent at 6 or 12 months, let alone after 1, 2, or even 5 years. And would there be any persistent benefits if someone lapsed in their yoga practice or only did yoga two times a week? As with almost any yoga study I read these days, I am on the one hand encouraged by the positive results of this one for giving healthy men some compelling reasons to take up yoga, and on the other hand am reluctant to sound the horns of triumph until larger follow-up studies support these initial findings. And that, sadly, costs a lot of money to do! Any billionaires out there looking to support some good works in the world?

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Got Salt? Yoga, the immune system, and the problem with some scientific studies

by Nina

Currents in Salty Water by Brad Gibson

So I’ve been seeing these articles about a particular scientific study circulating in the blogosphere that claimed the study was proof that yoga improved your immune system system. One example is from Can Yoga Boost Your Immune System? at salon.com, which claimed:

“This latest study confirms those findings, links them to the body’s immune system, and suggests this effect may be instantaneous.”

Naturally, as a dedicated yoga blogger, I decided I needed to check these articles out because I need to share the good news with our readers, too, right? But my initial readings left me scratching my head a bit (for example, “a comprehensive yoga program rapidly produces internal changes on a genetic level”), so I decided to consult with my handy scientist co-bloggers to find out more, specifically what the relationship is between changes in gene expression and the immune system.

Dr. Ram Rao put it this way:

“The article describes effects of Yoga on genes that influence the immune system. There are so many factors that affect gene expression (environment, diet, pollutants, stress etc) and so the authors looked to see if Yoga did the same.”

That makes sense, right? So far, so good. But Dr. Brad Gibson said it this way:

OK, what they were measuring was gene expression profile changes in PBMC.

"Right before and after each regimen, 20 ml blood was drawn, PBMCs were immediately isolated, total RNA was recovered and used in gene expression profiling experiments interrogating >47,000 independent transcripts in two hybridization runs"

First, PBMCS (according to Wikepedia) are "peripheral blood mononuclear cell (PBMC) is any blood cell having a round nucleus. For example: a lymphocyte, a monocyte or a macrophage. These blood cells are a critical component in the immune system to fight infection and adapt to intruders."

So, what they are suggesting is that the observed changes in the gene expression profiles in blood immune cells (PBMCs) in Yoga practioners is correlated with an improved immune function. However the second bit is pure speculation.  They see a change, but it's anybody's guess if this represents a better or healthy immune system.  They provide some guesses, but….

Okay, I admit it, that phrase “the second bit is pure speculation” was a bit disappointing. I’d just wasted my time (and theirs) on an idea for a blog post that I couldn’t really use because, after all, on this blog anyway, we try to back up our claims with good science. But a few days later I realized I actually had more of a contribution to make on the topic than some of the other blogs because while everyone else was simply parroting some kind of good news about yoga they didn’t really understand, I had an actual real-life scientist weighing in on the significance of the study and he said to take it with a giant BUCKET OF SALT.

However, before writing the post, I decided to do a bit more research by looking an the original scientific journal article that everyone was quoting from Rapid Gene Expression Changes in Peripheral Blood Lymphocytes upon Practice of a Comprehensive Yoga Program—you know, just in case. And here is the abstract from the study:

One of the most common integrative medicine (IM) modalities is yoga and related practices. Previous work has shown that yoga may improve wellness in healthy people and have benefits for patients. However, the mechanisms of how yoga may positively affect the mind-body system are largely unknown. Here we have assessed possible rapid changes in global gene expression profiles in the peripheral blood mononuclear cells (PBMCs) in healthy people that practiced either a comprehensive yoga program or a control regimen. The experimental sessions included gentle yoga postures, breathing exercises, and meditation (Sudarshan Kriya and Related Practices – SK&P) compared with a control regimen of a nature walk and listening to relaxing music. We show that the SK&P program has a rapid and significantly greater effect on gene expression in PBMCs compared with the control regimen. These data suggest that yoga and related practices result in rapid gene expression alterations which may be the basis for their longer term cell biological and higher level health effects.

Whoa, I’m thought, somehow we went straight from “wellness” and “benefits” to specific claims about the immune system. Then there were all those vague words like “suggest” and “may.” But, of course, I’m not scientist, so again, I consulted with Brad. Here is what he said: 

Look at their last sentence:
"These data suggest that yoga and related practices result in rapid gene expression alterations which may be the basis for their longer term cell biological and higher level health effects."

That is, they don't know whether the change in gene expression patterns they observed has anything to do with the yoga practice, let alone a more healthy immune system.  This is a general problem of small correlative studies of this type.  At best I would say this is an intriguing pilot study (low N, not really statistically significant enough to establish even correlation), which will need considerably more work to establish:
(1)  'causation' (i.e., yoga practice causes these genetic expression changes as opposed to some random or other variable that wasn't accounted for)
(2) 'benefit' (the expression changes that are observed are actually beneficial and lead to an improved immune system)
(3) 'mechanism' (why these gene changes lead to a more healthy or robust immune system).

My translation? The number studied was so low that correlation couldn’t be established. Causation definitely was not established. And then there was a bunch of speculation. So, yes, get out the salt everyone, and sprinkle liberally! (For you non-American readers out there, we have an expression “take it with a grain of salt” that means you should be skeptical about something. So I like to joke about buckets of salt, when I think a lot of skepticism is warranted. And, as much as we love yoga, this is not the first time we’ve looked at scientific studies of yoga that indeed warrant quite a bit of skepticism.)

Note: I’m pretty sure that yoga is good for the immune system, however. Stress compromises the immune system—this is known medical fact—and yoga reduces stress. Spending more time in Rest and Digest mode (where your body restores itself) rather than Fight or Flight mode (where your body depletes itself) is therefore good for your immune system.

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New Study Supports Our Personal Bias! Yoga is Good for Older Adults!

by Baxter

Baxter in My Yoga Room by Nina Zolotow

One of the benefits of our blog is that we get to keep up on all the latest developments in research on yoga and aging. Just the other day, Nina came across an abstract from the National Institutes of Health that piqued my fancy, which was titled “The effects of yoga on physical functioning and health related quality of life in older adults: a systematic review and meta-analysis.” Man, is that a mouthful! What the authors were interested in finding out was how yoga compared to other forms of physical activity. Well, let me have them tell you what their goal was:

“The goal was to review systematically the comparative effectiveness of yoga, compared with other exercise interventions, for older adults as shown on measures of health and physical functioning.”

Okay, so once again, researchers are limiting their look at yoga to the physical level of yoga asana, but to me, any advancement in acknowledging the benefits of yoga for aging is a step in the right direction.

So, how did they go about figuring out the answer to their question? Well, they scoured the studies that had already been done; in other words, they looked back to see what other folks had already done, instead of designing a new study of their own from scratch. This can be a helpful way of answering some questions, especially if you can find enough studies out there that meet your criterion to include in your analysis. In this case, they looked for studies published in English, done between 1950 and 2010, which were a certain kind of study that is considered more objective, and they looked in a variety of sources, including ones like PubMed. When all was sifted through, they found 18 studies that qualified and met their specific standards.

What their analysis of the data from these 18 studies yielded sounds pretty promising, with a few caveats where either the data was not so strong or just didn’t support yoga helping at all, like with cognitive issues such as Alzheimer’s Disease. Here’s what they found:

“[our analysis] suggested that the benefits of yoga may exceed (emphasis is mine) those of conventional exercise interventions for self-rated health status, aerobic fitness, and strength. However, the effect sizes were modest, and the evidence was mixed for yoga's effect on depression, sleep, and bone-mineral density. Studies did not find an effect on cognition.” 

As is almost always to case, they go on to say that while these findings are encouraging, what is needed is more studies, well-designed, with a lot more participants involved. Good news for future yoga therapists wanting to do research, but mixed news for the rest of us. But again, overall, any news like this is encouraging for those of us doing yoga regularly that our efforts do bear some good fruit. Perfect timing for this harvest season! And if we are lucky, Brad might lend us his scientific take on this study in a future post.

To read the abstract in its entirety, see here.
   

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Science, Aging, and Yoga

by Brad

Paris in the Rain by Brad Gibson 

So I promised I would get back to the question of how one would use science to study the effects of yoga on aging. As a starting point, let’s look at one highly publicized study that appeared a few years ago in Lancet Oncology (see here).

This work was collaboration between Elizabeth Blackburn, a prominent and highly respected biochemist at UCSF and recent Nobel Prize winner in Medicine, and Dean Ornish, a clinician at UCSF and well-known author of books and articles linking better nutrition to health and disease prevention, especially for coronary heart disease. The basic premise of their 2009 Lancet study was to examine whether relatively short-term lifestyle changes consisting of a low-fat diet, moderate exercise and yoga-based stress management could effect telomerase activity in circulating blood peripheral blood mononuclear cells (PBMCs) that are largely cells involved in immunity. 

The authors enrolled 30 men with a pre-diagnosed low-risk for prostate cancer for a three-month regimen. They measured telomerase activity, an enzyme present in certain class of replicating cells that maintains the length of telomeres. Telomeres are repetitive stretches of DNA at the ends of chromosomes that protect the integrity of chromosomes, and with each cell division gets shorter. Telomere shortening has been shown to negatively affect a cells capacity to replicate and general maintenance. Telomere shortening has been suggested as a biomarker of aging, acting as a type of clock for cellular aging. This so-called “telomere theory of aging” has gone out a favor among some scientists in recent few years, and its role in aging is controversial. Nonetheless, the basic premise underlying this study is that higher telomerase activity will lead to longer telomere lengths, which will set back the aging clock a bit in some way, or at least lead to healthier immune cells.

The author’s conclusions were as follows: “Comprehensive lifestyle changes significantly increase telomerase activity and consequently telomere maintenance capacity in human immune-system cells. Given this finding and the pilot nature of this study, we report these increases in telomerase activity as a significant association rather than inferring causation. Larger randomized controlled trials are warranted to confirm the findings of this study.”

What they mean here is that the number of patients in the study was low (N=30 is very small for a study of this type, and only 24 of these could actually be followed up the multiple times needed over this three-month period for technical reasons), the patients were pre-selected as having a clinical diagnosis of possible “low-risk prostate cancer” (that is, not a random group and probably motivated for a positive outcome), and that the results can at best be interpreted as an association and not necessarily a cause of the three-month lifestyle change (that is, just because thus group showed an increase in their telomerase activity, it doesn’t mean it resulted from the lifestyle intervention, but it could be the result of any one of a number of variables that were unaccounted for during this period, sometimes referred to as “confounders”).

But larger randomized properly controlled trials are expensive to run, and without a serious backer—the government or a drug company—don’t expect to see a follow-up any time soon. Just think about the large-scale trails of vitamin E that after many years and millions of dollars not only failed to establish a link but also showed a possible negative association. This is part in parcel of the tough love and art of large-scale clinical trials that are required if you want to prove something using rigorous scientific methods. 

So what did this study actually show? At minimum they showed what was needed for carrying out a larger study (power calculation) to actually determine a causal relationship. No mechanism was defined for why telomerase activity increased, although several were suggested (reduction in oxidative stress and inflammation, for example). Otherwise one shouldn’t draw too many conclusions from this study, especially since three independent variables were introduced (diet, exercise and yoga) and the study group was so small and biased. And one has to also keep in mind that the telomere length was not directly measured, as the authors themselves pointed out that telomere length changes would likely to be too small to measure in such a short time (three months). So I guess there’s another message to take home: some things take time.

Reports like these remind me of one of the reasons I have sympathy for the “N of 1” studies, that is, experimenting on yourself. Not real science, but you’ve got to try something. Take up yoga, improve your diet, have a walk everyday, and see what happens. 

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