Osteoporosis, Balance and Yoga

by Brad

A couple weeks ago, I attended a very interesting seminar on “Bone Marrow Adiposity:  An Age-Associated Phenotype; What's between bone and fat?  New insights into age-related osteoporosis” by Dr. Clifford Rosen, MD.  Dr. Rosen is the Director of the Center for Clinical and Translational Research at the Maine Medical Center Research Institute in Scarborough.  His talk was fairly technical and had to do with the regulation of fat in bone and how it increases slowly with age, as well as being affected by other environmental and genetic factors. His data showed that as fat accumulates in bone with age, it appeared to be related to a decrease in bone density, and therefore could be a driver of osteoporosis in both men and woman. He also stated that the clinical manifestation of osteoporosis is bone breakage, and therefore as your bone density decreases, it is the fall and inevitable bone fracture that typically turns people into patients. Avoiding a fall in the first place is possibly the best and for some the only way to avoid the adverse effects of this age-related decline in bone density.

After his seminar, I had a chance to talk with him after his research and asked him whether yoga might help by decreasing the risk of falling. He immediately said yes, and added that the yoga and tai chi were the two things that he knew that had been shown to have the greatest benefits in reducing this falling and bone fractures (see, for example, the Mayo Clinic web site's Exercising with osteoporosis: Stay active the safe way by choosing the right form of exercise and the New York Times article Ancient Moves for Orthopedic Problems). He implied that this was primarily through an increase in balance as opposed to strength. Indeed, while there is plenty of evidence that strength training is important, an increase in balance and flexibility can make all the difference between a stumble or misstep and a full-fledged fall.

As I sit on my flight to Seattle, I am reminded of how much variation exists in flexibility and balance among adults. Squeezing out of an aisle seat to make your way to the restroom or retrieving a suitcase from the overhead bin can easily become an awkward and precarious—and at times dangerous—act. And it is often not the oldest passengers, but the middle-aged and muscle-bound adults who induce serious cringing from neighboring passengers. Imagine how much more agile they would be if they all practiced yoga!

And for those of us who already do yoga, this is yet another compelling argument that working on balance is critical as we age. So if you haven't done so already, check out Shari's post last week about how to create a yoga practice to improve your balance (see Planning a Practice for Improving Balance).

Caloric Restriction: Comment and Response

by Nina and Brad

Brad’s post on caloric restriction (see Caloric Restriction and Longevity) prompted an interesting comment from Kathleen Summers MD PhD that I thought it worthwhile to share with you. Rather than having Brad respond in the comments section (I'm not sure how many of you actually read the comments), I asked him to reply to her comment at the end of this post. So have a look! This debate is a very good example of how little scientists currently understand about the aging process (a theme we return to periodically) and provides a hint of some of the many issues surrounding the controversy regarding the best diet for healthy aging.

Posted by Kathleen Summers MD PhD to YOGA FOR HEALTHY AGING

The biggest lesson here is that an excess of energy intake brings disease, disability, and early death. Restricting intake protects against cancer - and also diabetes, arthritis, and heart disease to some degree, although the numbers in the latest study didn't reach significance for the latter (potentially due to limited sample size). Teasing out just what the optimal amount of intake is takes time and research. And it's complicated - there's nutritional, environmental, mental/emotional health, and genetics among other factors playing a role.

The monkeys in both groups of the Wisconsin study ate more and weighed more than the NIH monkeys. The researchers used different sources for their proteins, fats, and carbs as well as a different approach to vitamin and mineral supplementation.

We have one primate study showing extended life span with calorie restriction and one not showing the same but yet other positive results. Let's not jump to absolute conclusions about what the latter study means.

Response from Brad Gibson PhD

Kathleen,

You make some good points, and I agree that this most recent NIA caloric restriction study needs to be considered within the context of other published work. There are undoubtedly many nuances in experimental design and interpretation that future experiments will need to address. That said, my major point is that the data for CR in primates is weak at best.  Many of my colleagues were very critical of the earlier Wisconsin study on two counts: the fact that they fed the control group a fairly high caloric diet and that they removed animals from their final analysis on the basis that they died from non age-related reasons. The removal of animals in the final statistical analysis was a very dubious call. And, as it was pointed out in the NYT article—and by many critics of the Wisconsin study—if those animals were included there was no difference in longevity between the two primate groups. Combined with other studies on more diverse genetic backgrounds in mice that show very mixed effects of CR, one really has to wonder how much traction the CR models has left in it, at least in mammals. Oddly, the data on other model organisms (flies, worms etc.) remain strong.  But one can only push these conserved evolutionary arguments so far.

While there may be benefits in a CR diet as you indicate (e.g., cancer and heart disease), one needs to make a distinction between a low calorie diet and caloric restriction. Many years ago a very prominent scientist in the field of aging who practiced the CR diet stated at the end of his seminar that "we scientists" needed to make a case to the public about the benefits of CR. I challenged him on this assertion, saying that American's relationship to food is so screwed up as it is, that to send a message that food is your enemy is not good advice. There is no evidence that CR in humans is beneficial. In contrast, there's plenty of evidence that a sound, balanced, healthy, low-to-moderate caloric diet (especially one that limits or avoid meat and dairy) is good for you. I suspect we are in agreement on that point.

I also agree that we are still far from drawing a final conclusion on the benefits of CR on human longevity. I was a bit flippant on this point in my last blog post. Guilty as charged. And there is little doubt that there will be more NIH studies examining CR and longevity in various mammalian and primate models as there is still compelling and interesting evidence that needs to be sorted when all animal models of CR and longevity are considered. However, I for one, will be placing my bets elsewhere.

Probability, Aging and a Pain in the Neck....

by Brad

It seems appropriate to discuss "probability" as I wait in my seat for takeoff on my flight to Vancouver on a sunny day in San Francisco in mid-may.  First probability calculation: what’s the likelihood that it will be sunny in Vancouver, a city a thousand miles north but also on the Pacific Coast? Better than the average expectation, but probably not by much given the low correlation between weather in the Pacific Northwest with that of the Bay Area, especially in late spring and summer.

Vancouver's Chinese Garden in the Rain by Nina Zolotow

I’m not sure how many calculations of this type most people make in a day, but I tend to think this way a lot (probability calculation #2: am I an outlier in this regard, say in the 5% fringe, or is this more common that I imagine?).  The reason to bring up probability with respect to aging is that most people don’t think about probabilities and randomness in looking at their future health—or their present state for that matter—and how it might change, for better or worse.  Or more to the point, how do changes you make right now influence your health, both in the near term as well as 10 or 20 years out (probability calculation #3: I expect to live say another 25 years or so to about 85, but 90 or so seems considerably more uncertain, even with a exercise, yoga and a good diet). 

Several months ago I was aghast to read a letter to the editor in the New York Times from a woman who couldn’t understand why she unable to get pregnant in her late thirties since she had been taken care of herself, had been eating well, and practiced yoga daily.  She apparently believed that her (good) behavior would insure health and fertility through her thirities.  Probability calculation #4: what is the likelihood that a woman in her late thirities can get pregnant relatively easily, and how much is this is improved if she's in relatively good health? I suspect the answer is that the improvement is small, despite what one might expect. This is just one of thousands of puzzling, fascinating, and at times callous probabilities that govern our lives in a world governed by processes that are themselves inherently random. Try as we might to make rational decisions that we believe will influence our present and future selves in predictable ways, this is clearly not the full story. 

The birth of modern quantum physics over one hundred years ago taught us that even the most basic particles that make up our universe—electrons, protons, light, etc.—are governed by rules that are probabilistic.  Einstein’s famous lament that “God doesn’t play dice with universe” was a last stand against the onslaught of quantum weirdness and other concepts that now dominate our thinking on the physical laws of the universe.  But biology is also subject to these same probabilities, such as the underlying molecular principles of random DNA mutations in evolutionary theory.  Biological aging also has many random elements, or stochastic processes. Indeed, some theorists have resisted any notion of programmed aging or defined biological process of aging per se, and rather believe that aging is inherently driven by the sum of hundred and thousands of random events every second that ultimately contribute to the overall aging process. As Yogi Berra once said, “If you see a fork in the road, take it.”

So as I sit in my airplane seat waiting for this trip to start, I also feel the pain in my neck that hasn’t gone away after a 23-day stretch of 10-12 hour days in front of computer working on grants and papers.  Oddly, I’ve done this many times before in my academic career, but hadn’t any neck pain that didn’t take more than a day or two go away. But I’m 59 now, and this time is different.  Probability calculation #6: if I just ignore this and take some ibuprophen for a few days, will it go away on its own?  As it turned out, no such luck….  It had seemed a reasonable bet since I had done nothing I hadn’t done many time before in the last 30 years.  But of course I hadn’t factored in the "aging" component in this calculation, or the probability that this behavior was now going to come at a price.  So now I’m looking at how I can change my yoga practice to help alleviate this new and unwanted development.  Calculation #7: what’s the chance that if I spend 20-30 minutes a day in a few key poses (Downward-Facing Dog with a wall, Standing Forward Bend, a passive backbend over a rolled blanket ) that my neck pain will improve or, better yet, heal completely?  I’ll let you know in a few weeks.

And one last thing, the weather in Vancouver was beautiful when we arrived, but was followed by five days of overcast skies and intermittent rain. It was a great trip.

Stressed Mind, Stressed Cells?

by Brad

Last Friday I attended a talk by Dr. Elissa Epel called “Telomeres, telomerase and mental states: Stressed mind, stressed cells?” According to the abstract Dr. Epel supplied in advance of her seminar:

"I will discuss our UCSF research on the telomere/telomerase maintenance system and relationships to stress and other psychological states and lifestyle factors. The length of our telomeres is a predictor of health status – early disease and mortality, and may serve as an index of biological aging. We now know from 8 years of research that shorter telomere length is related to states of suffering—anxiety, depression, trauma exposure, and chronic stress. Just how much can people stabilize their telomere length through interventions such as exercise and meditation? I will discuss initial findings, suggesting that this marker appears somewhat malleable."

Dr. Epel is an Associate Professor in the Department of Psychiatry at UCSF.  She is also a co-founder of Telome Health, Inc., a relatively new company located in the Bay Area to promote the use of telomere testing as a measure of biological age and overall health status. The basic idea that Dr. Epel was promoting is that chronic stress has a negative impact on telomere length, and that stress reduction through diet, exercise, and possibly other lifestyle changes can have preserve telomere length.

You may remember I posted a piece on this subject a couple months ago that discussed telomeres, yoga and aging ("Science, Aging and Yoga"). As a recap, telomeres are sequence of nucleotides or base pairs at the ends of your DNA that serve cap off and protect DNA integrity. One of the theories of aging asserts that decreased telomere length resulting from the failure of certain cell type in the body (immune cells, stem cells, etc.) to properly renew their telomere length after rounds of cell division via the action of telomerases (enzymes that add back lost telomere DNA) can lead to cellular senescence (a terminal, not dividing state) that could play a role in aging, acting as a sort of molecular clock. The question as to whether a reduction or low telomere length is responsible human aging or diseases is still hotly debate (see NY Times article here), despite many studies showing a correlation of shortened telomeres with cancer, diabetes, osteoporosis, Alzheimer’s and other chronic diseases of aging.

Ferns by Joan Webster

Personally, I found much of the data presented by Dr. Epel not especially convincing, as it was mostly correlative, and did not provide much if any mechanistic insight. However, I was intrigued by her attempt to link the physical and mental state of “stress” that we experience daily (you know, “I’m so stressed out”) to cellular stress and damage (alteration in the physiological state of cells or tissues that can lead to damage at the molecular and cellular level). Although we are all familiar with the former use of the term “stress,” this second usage of the term “stress” is quite different, and its effects can remain hidden until it manifests into a pathological or disease state.

It is well known that emotional stress can lead to an increase in cortisol and insulin levels, as well as increases in catecholamines and inflammatory cytokines. What is less clear is how these signals are integrated at the cellular and tissue level, especially under chronic stress, some of which are not at all obvious. Most studies measuring telomere length are on carried out on immune cells present in blood, as these cells are relatively easy to collect and originate from actively dividing cells. 

The notion that chronic stress could alter telomerase activity in these proliferating immune cell types, resulting in the shortening of the telomeres and causing these cells to lose their capacity to divide (“Immunosenescence”) is certainly an interesting hypothesis. Indeed, immunosenescence is increasingly being seen as a new target for drugs and/or biologics therapy by both pharmaceutical and biotech companies. According to data presented by Dr. Epel, one group of people that apparently has a statistically significant decrease in telomere length are long-term primary caregivers, a group that is regarded as suffering from chronic stress. People with long-term depression apparently also have a similar phenotype.

And as I have discussed in an earlier post, meditation and mindfulness practices have been proposed as ways to ward off the presumed negative effects of telomere shortening. (I say presumed, because it’s still not clear to what extent shortened telomeres are by definition a bad thing, or how much shortening of telomeres is required for any negative consequences.) The science on all this is still in the very early days. It may turn out that telomere length will be one more false lead in the ongoing search for biochemical measures of biological aging. And I would be extremely wary of any company advertising to measure your telomere length or that suggests that taking supplements to increase telomere length makes any sense at all. Unfortunately, there are a growing number of companies out there they do indeed make such claims. (To their credit, Telome Health appears to be considerably more circumspect in their claims and services than most.)

I suppose what interested me the most from Dr. Epel’s seminar is that it once again reminded me of the many avenues of medical research that are converging on the notion that chronic stress is a negative factor in human health and possibly a driver in premature or accelerated aging. While the details of how this actually happens is unclear, it is interesting to consider that one of the main, if not primary, benefits of practicing yoga might be to reduce stress.  Who knows, maybe it will turn out that yoga reduces stress at both the psychological and cellular level? Too early to tell, but stay tuned….

Successful Aging and the Thinking-Moving-Feeling Triad

by Brad

Early this month I attended a symposium sponsored by the Longevity Consortium at the Buck Institute for Research on Aging on “Environmental, Developmental, and Genetic Factors in Aging and Longevity.” There were lots of interesting presentations, especially on the search for genetic determinants for longevity, or what we call genome wide association studies (GWAS). It turns out that almost nothing survives rigorous statistical scrutiny at this level, suggesting that the genetic factors for long life are very complex and highly dependent on a host of environmental factors.

However, there was one talk on a very different subject that was of particular interest. Dr. Dilip Jeste from UCSD gave a lecture on the meaning of successful aging, and why almost no one asks patients directly to assess their views of their own aging experience.  Almost all definitions of successful aging (and again, many prefer the term “healthy aging”, although they are often used interchangeably) are based largely on the absence of age-associated physical disabilities, such as cardiovascular disease, diabetes, neurodegenerative disease, etc. Dr. Jeste made a compelling case that self-assessment of one’s physical and psychological well-being at advanced age is critical for a better determination of what constitutes “successful aging.” Interesting concept, and one that may be more in sync with the yogic idea of the mind-body connection and mindfulness.

Larch Tree in Autumn by Philip Amdal

Intrigued by this, I went on to look at some of Dr. Jeste’s publications on these topics, and came across a very recent editorial published last year in BMJ titled, “Promoting successful aging through integrated care” (see here). I was struck the following statement:

“Another way of dealing with physical and mental health comorbidity may be through use of interventions that simultaneously increase physical activity, cognitive stimulation, and positive affect, thereby affecting all three components of the thinking-moving-feeling triad implicated in poor health related quality of life.”

As I read this I thought this is a pretty good definition of yoga, a “thinking-moving-feeling triad.” Maybe not an especially elegant summation, but pretty succinct. But what followed next took me back a bit:

An example of such an approach is the use of “exergames”—entertaining video exercise games. If such approaches were specifically adapted to the needs of older people, they could conceivably affect obesity, diabetes, heart disease, and depression simultaneously.”

Exergames? Not exactly sure what the meaning of this is (I confess to a horrible vision of a group of seniors playing bingo while clapping their hands to a Lady Gaga video), but if that's the best example they can come up with then something is wrong. Is yoga still met with such suspicion in the medical and academic community that such an obvious and natural connection is not made here? Is it going to take another generation for the current (and aging) yoga practitioners to retire before this can go more mainstream?

As I wrote in my last blog entry, one of the main reason I started practicing yoga at the age of 50 was that I was looking for a more age-appropriate exercise routine that would provide me with more flexibility, balance and core strength without exposing me to injuries. Sounds to me like yoga would be a much better fit here addressing all three of these goals (“thinking-moving-feeling triad”) in a much more integrated and natural fashion….

Does Yoga Wreck Your Body? A Scientist's Perspective

by Brad

There’s been a lot of buzz after the Sunday Times article on yoga and injuries, "How Yoga Can Wreck Your Body." My own take on this is that this is pretty shoddy journalism. The writer should have looked no further than the New York Times own Science Times format for Q&A.  Maybe a question like “Does yoga cause more injuries than similar exercise regimens?” would have been more appropriate? I suspect the answer would have been “no.”

In any case what’s the control here? No exercise at all, running, or lifting weights at the gym? All of these have both intended and unintended consequences on your physical well-being and injury status, especially as you get older. When I was a graduate student at MIT, I remember one of my professors invoking his own law to explain missteps in some scientific papers: “if you think you know the answer beforehand, you will undoubtedly find it.”  He used this to explain why some scientists misinterpreted their results by either overly fitting data to some preconceived notion, or ignoring or explaining away other types of information that was inconsistent. Makes for a good story, but this is not good science. Not good reporting, either.

My own experience with yoga suggests a different perspective on this question. I started yoga when I turned 50 because I thought that it would be more age-appropriate and not lead to as many injuries. In my case (Caution! N=1), I never injured myself in nine years of practice.  One reason was I had a good teacher (Baxter Bell), who did not push his students too far, and who also paid attention to preexisting injuries to tailor their practice. He was also well-trained and knew about anatomy and physiology. Not all yoga teachers have the appropriate training, so this is one of the most important first decisions in your practice:  choose a good teacher.  Finally, I did not push myself beyond what I thought was appropriate (if it hurts, back off a bit—you're not trying to prove anything to the teacher or other students).

A Crow by Philip Amdal

While I did not injure myself in yoga these last nine years, I can’t say the same about other activities. I have suffered from tennis elbow injury (overzealous gardening and foosball), heel pain (bad shoes as a kid leading to something called Haglund’s deformity), and lower back pain (digging all day with a shovel a year ago to clear a section of the yard).  What’s interesting is how yoga has helped to alleviate and moderate these injuries. Downward Dog and other similar poses have helped stretch my Achilles heel and tendon, considerably reducing my foot pain. I use a strap around my arms now for various positions, and this has seemed to both strengthen and better align my arms and elbows. And, lastly, I have noticed that my lower back feels better after a yoga practice than before—as long as I don’t overdo things.  So, at least in my case, I can honestly say that yoga has helped alleviate injuries, not caused them. Maybe someone should write a follow up article, “How Yoga can Help You Recover from Injuries?” Not as sensational, but....

And speaking of shoddy journalism, Dr. Timothy McCall tells us that although he was quoted in the article, he was not actually interviewed by the author and that the quote from him was taken out of context, from an old article. To read his rebuttal and his advice about practicing headstand, see his website http://www.drmccall.com/ and read the article "How to Not Wreck Your Body Doing Yoga or, How I Really Feel about Headstand" on the home page.

Okay. Back to Aging.

by Brad

Okay. It’s been a while, as I’ve been busy with writing NIH grants and papers, as well as traveling. So it's time to get back to one of the central points of this blog: what is aging? It turns out this is no more clear than trying to define yoga. When I joined the Buck Institute for Research on Aging some 11 years ago, I was surprised and a little chagrined to discover how unsettled and wide open this central question of aging biology was.

This was not my original field of study, but as a chemist and structural biologist working at a major teaching university, I saw a prime opportunity to make a career shift by joining the Buck Institute and using my skill to elucidate molecular mechanisms of aging. But I had no idea how many competing theories existed on this subject, ranging from rather oblique terms like ”antagonistic pleotrophy” to more familiar ones—at least to a chemist—like “entropy” and “free radical damage.” So the other day when there was some news coverage in the New York Times of a breakthrough in aging research (see NY Times article here), I saw this as a chance to tackle this subject. The article, titled “In Body’s Shield Against Cancer, a Culprit in Aging May Lurk,” came out of the Mayo Clinic and looked at the role of senescent cells in aging (see original research here).

When cells reach a point of pathological state, either through telomere shortening or some other aberration or damage, a sequence of events are put into place that either sends these cells into a cell death pathway, or into a state of senescence, a kind of limbo non-dividing state. One reason this occurs is to avoid the formation of a cancerous cell, which the organism obviously wants to avoid. Cells that become senescent were usually thought of as sequestered cells that no longer posed a problem to the organism, but were also no longer productive. However, what this new study showed is that these senescent cells appear to have more damaging effects on neighboring cells and tissues, possibly through a secreted inflammatory signal.

Manzanita by Brad Gibson

By constructing a mutant mouse strain where the researchers could target and kill these senescent cells without harming the healthy cells, researchers found that it had a significant beneficial effect on the health of the mice, and that they lived longer. There is a lot of follow-up work to be done to confirm these studies in “normal mice” as well as in humans. In any case, the data are highly intriguing. It is also worth pointing out that when asked whether this would cure aging, the scientists were much more cautious, as they clearly understood that this is probably only one of many mechanisms that are contributing to aging. Nonetheless, it is interesting to see how inflammation comes up repeatedly as a cause or at least a driver of many age-related disease, from Alzheimer’s disease to diabetes.

One question that I would like to get back to is: what can we do as individuals to influence this process? What are the conditions that lead to cellular senescence versus cell death, for example, and what are the physiological and environmental determinants that cause as a cell to enter this critical state in the first place? If we knew the answers to these questions and as well other questions of this type, we might be able to critically examine how we can influence are own rate of aging. This question is related but separate from how we can reduce and/or cope with various age-related losses and pathologies as they emerge. Both questions will be critical to answer to reach an understanding on the practice of healthy aging.  How yoga might be a part of that practice is what we are trying to address here….

What is a Yoga Practice?

by Brad

A year or so ago I was talking with a colleague about a genomics study he was planning that was going to look at exercise and aging. Previously, he and his colleagues had shown that resistance exercise training had a significant effect on the genes that were transcribed in muscle tissue, and that the older people undergoing this training had gene transcription profiles that resembled much younger people. This time around they were planning a more nuanced study and would look at several exercise regimens, including yoga. I remembered asking him what type of yoga practice they planned to use, and was met with a slightly confused look. He wasn’t sure, but thought it was a “standard practice” involving some stretching and aerobic components. When I inquired further about whether it was Iyengar style or one of those high-energy aerobic practices (like Ashtanga Vinyasa), I realized that our discussion had reached a dead end. He had no idea what I was talking about.

Photo from Yoga: The Poetry of the Body by Yee and Zolotow

So when I ran across another article today on Yoga for Back Pain that was mentioned in the Science Times section of this weeks NY Times (see here), I decided to take a little closer look at what the actual practice was. I also looked back at the Ornish and Blackburn study I discussed a couple weeks ago (see here), as well as a few other studies I had run across. I was interested in seeing how well the practice was described and whether it made in sense.

I was surprised to find that the most high profile of these studies, the 2008 Ornish and Blackburn study (see here), had the least detail. What they described as yoga for stress management consisted of “gentle yoga-based stretching, breathing, meditation, imagery, and progressive relaxation techniques 60 min/day, 6 days/week”. In contrast, a study published this summer by Dr. Fishman on osteoporosis and yoga (see here ) was considerably more comprehensive, listing all 10 yoga poses by both Anglicized and Indian names, e.g., “Upward and Downward Dog poses (Adho Mukha Svanasana and Urdhva Mukha Svanasana),” as well providing an appendix of 13 figures illustrating each poses. It should be pointed out that the lead author of this study was extremely familiar with yoga, having practiced it in India for three before attending medical school.

Another group that was fairly thorough in their description was Sherman et al. which just appeared on-line a couple days ago (see here) in their study of chronic low back pain, where they describe a viniyoga practice consisting of 5-11 poses (with pictorial diagrams referenced from earlier 2005 paper by this same group (see here). Interestingly, these authors also provided the credential for the teachers as “instructors with at least 500 hours of viniyoga training, 5 years of teaching experience, and familiarity with the selected postures and who were briefed by our yoga consultant.” This paper also gave a defense of their yoga style (viniyoga), as “a therapeutically oriented style of yoga that emphasizes safety and is relatively easy to learn.” 

Iyengar-style yoga was used in another study examining stress and inflammation by Kiecolt-Glaser, et al (see here) because it ”emphasizes the use of props to help students achieve precise postures safely and comfortably according to their particular body types and need”. In this latter study, the 12 poses and timing of each were well described and was constant, and apparently selected “based on their purported relationship to immune function and/or restorative effects.”

Obviously not everyone is going to agree with what is a good or best yoga practice for stress, back pain, osteoporosis or whatever. But what is clear is that these studies need to provide a through description of the regimen (time, poses, teacher qualifications) and their overall rationale, so that if someone wanted to reproduce this study or compare it with another, they shouldn’t be in the dark as to what the yoga practice was. In the end, it’s you who is going to have to decide on what to believe, as the standards for comparing these practices, pose sequences, and yoga styles are confusing at best. Maybe Nina and Baxter can comment on this, as I’m not an expert.

CLARIFICATION: AGING, YOGA, AND SCIENCE

by Brad

Today’s post is largely in response to the question: How would one go about investigating the effects of yoga on aging scientifically? Before tackling this question—which I will get to in the next week or two—I will first attempt to define or at least discuss a few key terms and assumptions. The reasons for this will hopefully become clear.

In the broadest the terms, “aging” applies to how systems or entities change with time. To inanimate objects, such as your new car or jacket, this begins right after it’s manufactured or, more relevantly, after you bought it.  This process of aging can be rapid or slow (weeks, months, or years), and depends a lot on what the object is and what it was designed for.  In biological systems (including us), we typically think of aging as starting after development, or post-puberty in our case.  We also tend to associate aging with a decline and/or loss of functions, both physical and mental.  However, aging can include more positive properties or phenotypes, such as increased knowledge and skill sets, and it isn’t all that hard to name a few that fit into this category. But in most biological scientific studies of aging, we refer to aging mostly in the former sense, i.e., an accumulation of mostly pathological properties, such memory loss, frailty, neurodegenerative diseases, bone loss, muscle loss, and so on. Surprisingly there are quite a few competing theories of basic aging, such as error accumulation, telomere shortening, antagonistic pleiotrophy, free-radical theory, and entropy, just to name a few. What all (or most) of these theories seek to address is the underlying molecular and physiological event that drives these largely negative processes. 

Winter Trees by Brad Gibson

The term “successful aging” is more recent, having come into wide use in the last few decades. If you want to read more about this concept, I found the first chapter in the book Successful Aging: Perspectives from the Behavioral Sciences by Paul and Margaret Baltes quite useful (for information see Cambridge ebooks). 

Even last week as I read the science section of the New York Times (see NY Times), I came across a short review of a just-published study on “Alcohol Consumption at Midlife and Successful Ageing in Women: A Prospective Cohort Analysis in the Nurses Health Study” (see PLOS).  In this prospective correlative study, researchers at Harvard demonstrated that a modest increase in successful aging for women who consumed small, but regular amount of alcohol at mid-life. (Maybe a glass of wine after yoga class isn’t such a bad idea after all?). Here they defined "successful aging" in a more precise manner: "as being free of 11 major chronic diseases and having no major cognitive impairment, physical impairment, or mental health limitations." Of course, this more operational definition to successful aging made it easier to make clear and objective distinctions among the woman in this group, typical of population based epidemiological studies. 

When we chose the term ‘healthy aging’ for this blog, the purpose was to provide information not on just how practicing yoga might help to avoid or reduce your chances of acquiring one or more of these age-related losses, but also to better manage and minimize their impact when they occur. Indeed, this is the position most of us are in, whether is through the vagaries of our genetic background, chance, past behavior, or whatever. (This reminds me of the joke: Q: What’s the best thing you can do to insure a long life? A: Choose your parents well.) So as I go back and reconsider the original question on how science can study the relationship of yoga and aging, I will reframe this question a bit: How can science study the effects of yoga on our overall physical and mental health as we age? I’ll tackle this question next time….  But as a preview, there are few good places to start, including the 2009 pilot study in Lancet on comprehensive lifestyle changes and telomere length (a biomarker of aging and cellular senescence) and several recently funded NIH studies examining yoga’s effects on depression, fatigue, and menopause. 

And please leave any questions for the Friday Q&A in the comments.

FULL DISCLOSURE

by Brad Gibson

Okay, so it took me ten years to finally listen to my wife Nina and take up yoga. I may be slow, but I’m not an idiot.  So what was the epiphany? There were actually several. 

The first was listening to my wife Nina and Rodney Yee at a book signing in Los Angeles talk about how restricted most of us are in using and exploring our bodies. As adults we typically sit, stand up, walk, and lie down.  That’s pretty much it. Compare this to our younger selves, where we rolled down hills on our bellies, spun ourselves so we were so dizzy we crumpled to the ground, and did handstands on the lawn.  And all that just for the fun of it.

The second was attending a seminar given by a well-regarded scientist from the University of California San Francisco.  Here I learned about the startling plasticity of the human brain, and its ability to rewire and reorganize itself based on various environmental and behavioral stimuli. One particular example struck me: that the regions in the brain that control movements to our fingers are spatially distinct and this spatial resolution and control can be lost if the hand is constrained in motion over long periods of time. These regions then shrink and become partially fused, resulting in the inability to use the hand in a way we are accustomed, and more like a paw. The good news was that this is largely reversible if the constraint is removed.  The brain—along with the slow recovery of the hand —can then restore these neural connections. The significance to our aging brain and body was clear, both in a negative and positive sense. We must actively fight against the restricted physical activity that we impose on ourselves, as well as the loss of dexterity that is the result of this behavior. Otherwise, this can become a vicious cycle as we react to our aging bodies by imposing further restrictions to our movements, and our brain’s ability to control and balance these movements becomes diminished as a result. 

The Light on the Water (from Muir Beach) by Brad Gibson

My third epiphany was a bit more vain, but important to me nonetheless. As I was attending a party in the Berkeley hills on a warm summer evening, I was struck by how many beautiful women were there. Now this party was not one of the faculty or science-type parties that I usually attend, but one made up of by yoga practitioners of many stripes and ages. But as I pondered this—admittedly over a few glasses of very good vodka and some really delicious food—I realized that these people held their bodies in a posture and poise that I was not generally accustomed to. They were not just physically fit, but healthy and vibrant. Okay, my wife did point out the next morning as I told this story that I not only didn’t have my glasses on, but was also pretty drunk by this point. Fair enough. But over the years—and under more sober conditions—I have found this observation to hold up pretty well. 

So as a scientist who studies the biology of aging and the many disease that are associated with aging, I have come to my own personal conclusions on the importance of practicing a mind/body discipline like yoga. And as I approach my 59^th birthday, the immediate realities of physical and mental loss become more apparent. And I am not one of those people who think I can avoid this. I do believe, however, that we have the capacity to regain some of theses age-related losses, and if not, at least slow down their progression. Regaining or maintaining a higher level of balance, physical dexterity, and cognitive function and resolution is therefore something that is attainable and has the capacity to make huge impacts on the quality of our lives. The aging component that works against all this and drives these declines, however, is scientifically and mechanistically poorly understood. This is what makes my scientific life and work so interesting. But as far as I can tell, the basic processes underlying human aging are largely inescapable, at least as we currently understand them. That doesn’t mean we can’t intervene or we have to give up, nor that some of the losses we associate with aging can’t be mitigated.  We probably need to practice both acceptance and active engagement as we confront our own aging—part of the underlying philosophy of yoga that I am still struggling with. In any case, it can’t hurt to strive to feel better and think more clearly. There are few things that I would consider more important.

My primary interest in participating in this ongoing discussion on “yoga for healthy aging” is to examine evidence on how practicing yoga might intervene and in some cases reverse some aspects of the mental and physical decline we think of as normal aging. In doing so I have to first acknowledge that there is a lot of crap out there, and as a scientist I would want to bring rigorous and critical thinking to the process of evaluating these claims. Most published studies or claims just don’t stand up to rigorous scientific and statistical scrutiny because of poor study design, small sample size or the lack of good controls. But I also I don’t want to fall into the trap of constantly seeking to debunk or ridicule studies that attempt to establish a connection between yoga (or other related disciplines) and possible beneficial effects on aging or limiting age-related diseases. Rather, I’m more interested in trying to extract whatever useful information I can from these aging studies and see if it can be applied to improving one’s yoga practice.

And lastly, a full disclosure: I’m a firm believer in science.  I am also a believer in western medicine, although with some qualifications.  My concern with western medicine is that it can overreach itself at times and rely on vastly incomplete scientific knowledge in coming to diagnosis or treatments.  Or worse yet, it can incorporate many cultural biases. That said, it’s by far the best and most successful form of medical practice that we have. I am also aware of limitations in the scientific method. Not so much as a philosophy or discipline, but rather from the standpoint of recognizing the difficulty of scientific inquiry in tackling highly complex phenomena or systems. And as complex biological systems go, humans are at the top. This makes it exceedingly difficult for scientists to predict, investigate or fully understand how we respond to various environmental, temporal and behavioral changes. And yes, yoga would fall under these latter categories, as would aging itself.

Despite all this, I believe there are important things that we can do that can impact and alter our aging status and overall health, and that yoga has the potential to be a key player in this process. Indeed, some reasonable information already exists on how yoga might lower blood pressure, or reduce muscle atrophy (sarcopenia), stress, or cognitive decline.  These and other such topics will be ones that my colleagues and I will try and tackle.

Do any of you have questions for our scientist?