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All, Bone health is a perennial topic of discussion for folks practicing CR. I'm not quite as personally concerned about bone health on CR as I used to be for several reasons: In both humans (Fontana et al. PMID: 20969721) and mice (PMID: 26572927), CR appears to result in lighter, but perhaps not more fracture-prone bones, particularly once body weight is factored in, as we discussed in this thread. I practice both weight bearing exercise (jogging & resistance training) which is known to help build or at least maintain bone health. I practice cold exposure to increase brown adipose tissue (BAT). The amount of BAT tissue a person has is positively and quite strongly correlated with their bone mineral density at all measurement sites, independent of their body weight (PMIDs 22259053 and 24140784) as discussed here. This is particularly encouraging for us skinny folks, since BMD is usually associated with higher weight, but BAT is generally much less prevalent in obese people - suggesting (but obviously not proving...) you can be skinny but still have strong bones as long as you've got BAT. Nevertheless, I still have lingering doubts about the potential negative impact of long-term CR on bone health for my own case and in general. Read this for a scary anecdotal perspective from a former CR practitioner whose osteoporosis made him quit CR and spend a few years in rough shape, trying to build back his bone health. While he acknowledges his diet wasn't optimal, it's still a somewhat troubling story. So with these lingering concerns in the back of my mind, I was quite interested to come across recent evidence on topic germane to bone health that we discussed (and some of us even practiced) many years ago on the CR list, namely vibration therapy. I actually (re)discovered whole body vibration (WBV) therapy accidentally, in my never-ending search for ways to boost BAT. Remarkably, it turns out that WBV boosts BAT levels in rats (PMID 26125027), mice (PMID 25317067) and people (PMID 23423629), as discussed here. It also appears to improve balance, boost leg muscle strength & power, and promote weight & visceral fat loss . But perhaps the most interesting and relevant effect of WBV is it's influence on indicators of bone health, specifically bone mineral density (BMD) - a metric whose relevance for CR folks is questionable (given our thinner but not necessarily weaker bones), but which serves as the gold standard for bone health in the medical community. Several individual studies  as well as systematic reviews [2-5] found that WBV builds bone mass, in some cases as well or better than exercise . There was a recent randomized (allegedly placebo controlled!?) trial  of WBV therapy in 174 elderly men and women, which only found a non-significant trend towards improved BMD after 24 months of WBV therapy for 10 minutes per day. I seems to me the likely explanation for the disappointing results of  tells us something interesting about the right protocol for effective WBV therapy for bone health and other benefits. But first, a little history. Anyone who recalls the ancient CR email list discussion of vibration therapy will remember that the only viable and affordable, DIY option for many of us at the time were massage seat covers like this one - which were really quite pitiful in terms of their ability to create any sort of significant, and therefore effective, vibration. The tiny eccentric rotating mass motors used in this type of massage seat just don't have the mass or the power to create a very strong vibration effect. They might feel soothing, but they aren't likely to build bone mass. So I gave up on this sort of vibrating seat massager as a bone-building therapy years ago. I suspect others did as well. And this sort of lack of vibration power appears to be the explanation for the failure of WBV therapy to result in improved BMD in . In particular  used a vibration frequency of 37 Hz, which is in the range shown in other studies to be efficacious, but used a very mild 0.3g vibration magnitude - which is really quite anemic. In fact, the weakness of the vibration may be why they could characterize their study as a placebo-controlled trial, since simply standing on the motionless vibration platform may have not felt much different from turning the machine on for the so-called "active" treatment! In contrast, studies where WBV has proven effective at improving strength, reducing BMI and building BMD used a much more vigorous vibration protocol. For example  used a similar, although slightly higher, vibration frequency (40-60hz), but the real difference was in the vibration amplitude. In , the vibration plate had a motion range of 2-5mm. That may not sound like much, but at 40-60 Hz, those tiny excursions result in pretty strong G-forces. For example, the manual for the vibration plate I'm now using (see below), says a 2mm, 40Hz vibration pattern results in an acceleration of 6.5g, and a 5mm, 40Hz vibration pattern results in 16.2g acceleration, which are 22x and 54x more vigorous, respectively, than the vibration protocol used in the failed RCT . At the higher end of the vibration frequency used in  (i.e. 60Hz rather than 40Hz), the acceleration forces would be even higher. Here are some other protocols detailed in  (full text - I highly recommend this paper for anyone interested in pursuing WBV further) that have proven effective: In a study by Verschueren et al. [ref], in which the subjects were exposed to vertical vibrations 3 times per week for 24 weeks (35-40 Hz; 1.7-2.5 mm; 2.28-5.09 g), reported an increase bone mineral density of the femur. [T]he study of the Von Stengel , which included 108 postmenopausal women randomly assigned to three groups: 1) pivotal vibration platform (PVT - 12.5 Hz; 12 mm [excursion]), 2) vertical vibration platform (VVT), which had three 15-minute treatments per week (both groups had a magnitude of vibration of 8 g) and 3) control/fitness group which had two low-intensity workouts per week. They came to the conclusion that bone density increased significantly when it comes to the lumbar spine (PVT + 0.7% ± 2.2% and VVT + 0.5% ± 2%), while, when it comes to the femur, progress which was recorded in both vibration groups (PVT + 0.3% ± 2.7% and VVT + 1.1% ± 3.4%) was not statistically significant. The control group’s bone mineral density was decreased in the lumbar spine (-0.4% ± 2%), whilst the femur bone mineral density was maintained at the same level (-0.0% ± 2.1%). The study of Ruan et al. [ref] showed the highest increase in bone mineral density. In fact, after 6 months of 10-minutes, 5 times per week, vibration training at a frequency of 30 Hz and amplitude of 5 mm (overall magnitude 18 g), on a sample of 116 postmenopausal women, these authors recorded an increase in bone mineral density at the lumbar spine by 6.2% and hip by 4.9%, compared to control (n = 50) group. Interestingly, also from , comes this encouraging analysis for us skinny folks: Also, noteworthy is that, in that same study, after a post hoc analysis, authors [ref] found statistically significant differences in women with low body weight (<65 kg) as opposed to the heavier ones, where difference was not statistically significant. These authors found that women with lower body weight, in this case, below 65kg, recorded the best effects. Namely, compared to the placebo group, they have achieved a relative benefit in bone mineral density values of 2.1% at femoral neck, 1.92% at trochanter and 3.35% in lumbar spine. Also from  comes this discussion of another failed WBV trial whose protocol was apparently too weak: The best proof that the correct determination of the frequencies and amplitudes can be very important can be found in a study by Rubin et al. [ref]. In their study, after 12-month treatment that included daily, 2x10 minutes, vibration training (30 Hz; 0.2 g; 0, 5 μm), authors  showed a decrease in bone mineral density in experimental (-0.69%) and placebo (-0.27%) group at femur (-0.69%; -0.27%), the trochanter (-0.07%; -0.19%) and the lumbar spine (-0.51%; -0.65%). Such small differences after this extensive treatment (12 months x 7 days x 2 x 10 min) can be found in the intensity that was not enough to, not only increase the anabolic effects, but also inhibit the resorptive ones. This can be primarily attributed to very small amplitude, which was less than one millimeter. So it looks like WBV therapy can be effective, even in skinny older folks, but at least several G's of acceleration are required for WBV therapy to work. Fortunately, the technology available to consumers at an affordable price today has improved dramatically since the early 2000s when I last pursued vibration therapy with a seat massager. In fact, thanks to Kenton's recommendation (thanks Kenton!), I'm now the proud owner of a vibration plate that hits the sweet spot of the effective WBV protocols described above. It cost $179 on Amazon but shipping from them was extra. So I actually bought it for a couple dollars more on ebay with the advantage of free shipping, saving more than $20 on overall cost. It shipped the same day I ordered it, and arrived quite quickly (3-4 days) considering it's large size - the box was almost 3'x3'x1' and weighed 30-40 lbs. I've been using it now for about a week and really like it. It's quite rugged and I expect it to last. Kenton says he's been using his everyday for about a year. Here is what it looks like based on the manufacturer's image posted to Amazon: It's hard to get a feel for just what it's like and how big it is, from these pictures, so here is one I took of myself standing on it in the posture I've been using: Notice the straps? I think they are designed to help maintain stability. It's quite a weird sensation, and I can imagine someone losing their balance and falling off, particularly if frail. But as a bonus, I find by holding the straps taut, they help to couple my shoulders and back to the vibration, rather than just my legs, thereby (hopefully) increasing the bone-building effects on my spine. As I alluded to, the specs on the machine put it directly in the sweet spot for the therapeutic vibration magnitude observed in the studies cited above. In fact, just like , it has an excursion range of either 2 or 5 mm (the 'soft' vs 'strong' settings) and an adjustable frequency of 5 to 42Hz. According to the manual, at 42Hz the plate generates a 7.1g vibration on the 'soft' setting and 17.8g on the 'strong' setting. Quite in line (if not a bit higher) than the studies I cited which found benefits. Subjectively, it's really quite vigorous and downright weird feeling, particularly on the max (17.8g) setting. It's nothing like the very gentle vibration you feel with the kind of seat massager I experimented with previously. I can well imagine this sort of stimulus could have physiological effects. I fact, I've been keeping the sessions brief - only 1-2 minutes once or twice a day. As I understand Kenton uses it in a similar fashion. The vibration is so vigorous in fact, it's worth considering contraindications. Again from review article : Contraindication factors for the use of vibration training, enlisted by the manufacturers themselves [refs] are: the existence of kidney or bladder stones, epilepsy, cancer, pacemaker, recent implantation or surgery, thrombosis, hernia, rheumatologic arthritis, migraine, some cardiovascular problems and spinal injuries. Slatkowska et al. [ref] stated that there is no risk of using vibration training, and that it represents a new, promising modality for improving the characteristics of the skeletal system in postmenopausal women, respectively, same authors stated that the whole body vibration training increases muscular strength and power and slows down bone mineral density loss. Also, Russo et al. [ref] reported that there were no adverse effects of vibration training for women in menopause and post-menopause. The only side effect that was observed was increased itching in the lower extremities, more specifically, 6 of 17 participants, who were included in high magnitude vibration training reported these side effects. Moawed and Mohammed [ref] have explained in their study that the itching that occurs during the first use of the vibrating stimulus is the result of an increase in skin blood flow. In addition, in that same study, knee pain was reported by two obese subjects diagnosed with osteoarthritis, but it withdrew after a few days allowing subjects to continue with the treatment. Besides that, it is noteworthy that some authors [ref] claimed that at frequencies above ~50 Hz severe muscle soreness and even hematoma may emerge in untrained subjects, but this hasn’t been empirically tested due to the ethics issue. Overall, I'm very satisfied with the purchase, and pretty optimistic based on the available evidence that the vibration therapy this machine delivers has the potential to be beneficial for building bones, brown/beige fat, and perhaps even muscle. I think this would be especially true for people who aren't already naturally as active as I am. I'm interested what others think. Kenton, I know you've been using this same machine for a while. Anything you would add? Exactly how are you using the machine (settings, frequency, duration etc)? TomB, I know you're interested in optimizing your time spent exercising. Maybe it would be worth adding a brief bout of vibration therapy to your protocol? James Cain, I asked you about vibration therapy when we were together (in the exercise room!) at the CR Conference. You expressed skepticism about its likely efficacy, but acknowledged you hadn't looked at it too carefully lately. Does any of the evidence presented above change your mind? --Dean ----------  Int J Med Sci. 2013;10(3):307-11. doi: 10.7150/ijms.5161. Epub 2013 Feb 2. Ten-week whole-body vibration training improves body composition and muscle strength in obese women. Milanese C(1), Piscitelli F, Zenti MG, Moghetti P, Sandri M, Zancanaro C. Free full text: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3575626/ This work explored the short-term effect of whole body vibration (WBV) training on anthropometry, body composition and muscular strength in obese women. Fifty obese women (age = 46.8 ± 7.81[sD]y; BMI = 35.1 ± 3.55 kg/m(2)) were assigned to a ten-week WBV training period, two times a week (in each session, 14 min vibration training, 5 min rest; vibration amplitude 2.0-5.0mm, frequency 40-60 Hz), with (n = 18) or without (n = 17) radiofrequency, or to a non-exercise control group (n = 15). Subjects were instructed not to change their habitual lifestyle. Before and after the ten-week experimental period, anthropometric measurements, dual-energy X-ray absorptiometry (DXA), and the leg press, leg curl and leg extension strength tests were carried out. All changes in the two groups of WBV training, with or without radiofrequency, were similar and these groups were combined in a single WBV intervention group. As compared to controls, subjects submitted to WBV training had significantly lower BMI, total body and trunk fat, sum of skinfolds and body circumferences. On the other hand, lower limb strength tests were increased in the WBV group. These preliminary results suggest that WBV training may improve body composition and muscular strength in obese women and may be a useful adjuvant to lifestyle prescriptions. PMCID: PMC3575626 PMID: 23423629 ------------  Disabil Rehabil. 2012;34(11):883-93. doi: 10.3109/09638288.2011.626486. Epub 2012 Jan 6. Efficacy of whole body vibration exercise in older people: a systematic review. Sitjà-Rabert M(1), Rigau D, Fort Vanmeerghaeghe A, Romero-Rodríguez D, Bonastre Subirana M, Bonfill X. Author information: (1)Blanquerna School of Health Science, Universitat Ramon Llull, Barcelona, Spain. email@example.com PURPOSE: The aim of this study was to perform a systematic review of the literature on whole body vibration programs in older population and a meta-analysis of randomized controlled clinical trials. METHOD: A search was conducted in MEDLINE, EMBASE, CENTRAL, CINAHL and PsychINFO databases. We included randomized controlled trials evaluating the efficacy and safety of whole body vibration training in older populations compared to conventional exercise or control groups that assessed balance, muscle strength, falls, bone mineral density and adverse events. RESULTS: Sixteen trials met the inclusion criteria. Comparing the vibration and the control group, we found that vibration significantly improved knee muscle isometric strength (18.30 Nm, 95% CI 7.95-28.65), muscle power (10.44 W, 95% CI 2.85-18.03) and balance control (Tinetti test: 4.5 points, 95% CI 0.95-8.11). Comparison with a conventional exercise showed that the only significant difference was bone mineral density in the femoral neck (0.04 g/cm(-2), 95% CI 0.02-0.07). There were no serious complications in most of studies. CONCLUSION: Whole body vibration training may improve strength, power and balance in comparison with a control group, although these effects are not apparent when compared with a group that does conventional exercise. PMID: 22225483 -----------  Sportverletz Sportschaden. 2014 Sep;28(3):125-31. doi: 10.1055/s-0034-1366545. Epub 2014 May 14. [Does muscle activation during whole-body vibration induce bone density improvement in postmenopausal women?--A systematic review]. [Article in German] Calendo LR(1), Taeymans J(2), Rogan S(2). Author information: (1)Fachhochschule Südschweiz, Departement Graubünden, Landquart, Schweiz. (2)Berner Fachhochschule, Fachbereich Gesundheit, Disziplin Physiotherapie. BACKGROUND: Whole body vibration training (WBV) stimulates muscles by mechanical vibrations. The resulting muscle activity and bone deformation may provoke an increase in bone density. The aim of this systematic review was to evaluate whether muscle activation and muscle strengthening caused by vibration training has an effect on bone density in postmenopausal women. METHODS: This systematic review was conducted according to the guidelines of the PRISMA statement for meta-analyses and systematic reviews. The literature search was conducted in several electronic databases (PubMed und CINAHL) and Google Scholar. The literature search was conducted between June 2012 and August 2013. The methodological quality of the included studies was assessed using the Cochrane risk of bias tool by two independent persons. RESULTS: A total of 246 studies was found. In this present analysis three studies with vertical and two studies with side-alternating WBV were included, totalling 368 participants with an age range between 60.7 and 79.6 years. From those 132 participants trained on vertically while 67 participants trained on side-alternating WBV engines. The included study shows a moderate to high risk of bias. The selected frequencies ranged from 12.0 Hz to 40.0 Hz for vertical WBV and 12.5 Hz for side-alternating WBV. The amplitude ranged between 1.7 and 12.0 mm with an acceleration from 0.1 to 10.0 g. CONCLUSION: This systematic review showed significant influences on the isometric maximal voluntary contraction (IMVC) between 15.1 and 16.5 % and on dynamic maximal strength (DMS) between 7.9 to 16.5 % after vertically WBV (frequencies: 30.0 to 40.0 Hz; 3 sessions per week; 15 minutes per session) and on IMV with 26.6 % (frequency: 12.5 Hz; 3 sessions per week; 15 minutes per session). This increased muscle activity resulted in an improved bone density in the lumbar spine between 0.5 % to 0.7 % and the hip between 0.8 % to 0.9 % in postmenopausal women. These clinically significant findings should be confirmed by a large high-quality randomised controlled trial and reported following the CONSORT Statement guidelines. © Georg Thieme Verlag KG Stuttgart · New York. PMID: 24828509 ---------  J Osteopor Phys Act 3:150. (2015) doi:10.4172/2329-9509.1000150 Whole Body Vibration Training Effects on Bone Mineral Density in Postmenopausal Osteoporosis: A Review. Abazovic E, Paušic J, Kovacevic E Free full text: http://www.esciencecentral.org/journals/whole-body-vibration-training-effects-on-bone-mineral-density-inpostmenopausal-osteoporosis-a-review-2329-9509-1000150.php?aid=58099 Abstract Objective: Evaluate long term whole body vibration training effects on bone mineral density in postmenopausal osteoporosis. Background: Osteoporosis has been defined as a skeletal system disease characterized by low bone density and deterioration of bone microarchitecture which results in increased risk for fracture occurrence and predisposes the person to injury. Whole body vibration therapy showed positive effects on Bone mineral density. Materials and methods: Literature and scientific papers review of was conducted through the use of several databases: Science Direct, Web of Science, SCIdirect, PubMed, Taylor and Francis Online, Springer Link, SAE publications, JAMA Pediatr Idea: drexler e-repository and archives, Google Scholar and City Library Marko Marulic Split University Library in Split Online catalog. Conclusion: Whole body vibration training is a relatively new and promising non-pharmacological method for bone mineral density decline prevention. ------  Osteoporos Int. 2010 Dec;21(12):1969-80. doi: 10.1007/s00198-010-1228-z. Epub 2010 Apr 21. Effect of whole-body vibration on BMD: a systematic review and meta-analysis. Slatkovska L(1), Alibhai SM, Beyene J, Cheung AM. Author information: (1)Osteoporosis Program, University Health Network/Mount Sinai Hospital, Toronto, ON, Canada. SUMMARY: Our systematic review and meta-analysis of randomized controlled trials (RCTs) examining whole-body vibration (WBV) effect on bone mineral density (BMD) found significant but small improvements in hip areal BMD (aBMD) in postmenopausal women and in tibia and spine volumetric BMD in children/adolescents, but not in other BMD measurements in postmenopausal women and young adults. INTRODUCTION: Animal experiments report anabolic bone changes in response to WBV, but data in humans are limited. Our objective is to conduct a systematic review and meta-analysis of RCTs examining WBV effect on BMD. METHODS: Eligible RCTs included randomized or quasi-randomized trials, with follow-up of ≥ 6 months, examining WBV effects on BMD in ambulatory individuals without secondary causes of osteoporosis. The weighted mean differences between WBV and control groups in absolute pre-post change in spine and hip aBMD, and in spine and tibia trabecular volumetric BMD (vBMD) were calculated. RESULTS: eight RCTs in postmenopausal women (five RCTs), young adults (one RCT), and children and adolescents (two RCTs) were included. The regimens were heterogeneous, study durations were relatively short, and available data was mostly per-protocol. In postmenopausal women, WBV was found to significantly increase hip aBMD (0.015 g cm(-2); 95% confidence interval (CI), 0.008-0.022; n = 131) versus controls, but not spine aBMD (n = 181) or tibia trabecular vBMD (n = 29). In young adults, WBV did not increase spine or hip bone mineral content, or tibia trabecular vBMD (n = 53). In children and adolescents, WBV significantly increased spine (6.2 mg cm(-3); 95% CI, 2.5-10.0; n = 65) and tibia (14.2 mg cm(-3); 95% CI, 5.2-23.2; n = 17) trabecular vBMD. CONCLUSIONS: We found significant but small improvements in BMD in postmenopausal women and children and adolescents, but not in young adults. WBV is a promising new modality, but before recommendations can be made for clinical practice, large-scale long-term studies are needed to determine optimal magnitude, frequency, and duration. PMID: 20407890 ----------  J Osteoporos. 2014;2014:702589. doi: 10.1155/2014/702589. Epub 2014 Jun 18. Effects of whole body vibration and resistance training on bone mineral density and anthropometry in obese postmenopausal women. Zaki ME(1). Free full text: http://www.hindawi.com/journals/jos/2014/702589/ Objective. The aim of this study was to evaluate the impact of two exercise programs, whole body vibration and resistance training on bone mineral density (BMD) and anthropometry in obese postmenopausal women. Material and Methods. Eighty Egyptian obese postmenopausal women were enrolled in this study; their age ranged from 50 to 68 years. Their body mass index ranged (30-36 kg/m(2)). The exercise prescription consisted of whole body vibration (WBV) and resistance training. Bone mineral density (BMD) and anthropometrical parameters were measured at the beginning and at the end of the study. Changes from baseline to eight months in BMD and anthropometric parameters were investigated. Results. BMD at the greater trochanter, at ward's triangle, and at lumbar spine were significantly higher after physical training, using both WBV and resistive training. Moreover, both exercise programs were effective in BMI and waist to the hip ratio. Simple and multiple regression analyses showed significant associations between physical activity duration and BMD at all sites. The highest values of R (2) were found for the models incorporating WBV plus BMI. Conclusion. The study suggests that both types of exercise modalities had a similar positive effect on BMD at all sites in obese postmenopausal women. Significant association was noted between physical activity and anthropometric variables and BMD measures at all sites. PMCID: PMC4086652 PMID: 25136473 ------------  J Bone Miner Res. 2015 Jul;30(7):1319-28. doi: 10.1002/jbmr.2448. Low-Magnitude Mechanical Stimulation to Improve Bone Density in Persons of Advanced Age: A Randomized, Placebo-Controlled Trial. Kiel DP(1,)(2,)(3), Hannan MT(1,)(2,)(3), Barton BA(4), Bouxsein ML(3,)(5), Sisson E(6), Lang T(7), Allaire B(5), Dewkett D(1), Carroll D(1), Magaziner J(8), Shane E(9), Leary ET(10,)(11), Zimmerman S(12), Rubin CT(13). Nonpharmacologic approaches to preserve or increase bone mineral density (BMD) include whole-body vibration (WBV), but its efficacy in elderly persons is not clear. Therefore, we conducted the Vibration to Improve Bone in Elderly Subjects (VIBES) trial, a randomized, placebo-controlled trial of 10 minutes of daily WBV (0.3g at 37 Hz) in seniors recruited from 16 independent living communities. The primary outcomes were volumetric BMD of the hip and spine measured by quantitative computed tomography (QCT) and biochemical markers of bone turnover. We randomized 174 men and women (89 active, 85 placebo) with T-scores -1 to -2.5 who were not taking bone active drugs and had no diseases affecting the skeleton (mean age 82 ± 7 years, range 65 to 102). Participants received daily calcium (1000 mg) and vitamin D (800 IU). Study platforms were activated using radio frequency ID cards providing electronic adherence monitoring; placebo platforms resembled the active platforms. In total, 61% of participants in the active arm and 73% in the placebo arm completed 24 months. The primary outcomes, median percent changes (interquartile range [iQR]) in total volumetric femoral trabecular BMD (active group (2.2% [-0.8%, 5.2%]) versus placebo 0.4% [-4.8%, 5.0%]) and in mid-vertebral trabecular BMD of L1 and L2 (active group (5.3% [-6.9%, 13.3%]) versus placebo (2.4% [-4.4%, 11.1%]), did not differ between groups (all p values > 0.1). Changes in biochemical markers of bone turnover (P1NP and sCTX) also were not different between groups (p = 0.19 and p = 0.97, respectively). In conclusion, this placebo-controlled randomized trial of daily WBV in older adults did not demonstrate evidence of significant beneficial effects on volumetric BMD or bone biomarkers; however, the high variability in vBMD changes limited our power to detect small treatment effects. The beneficial effects of WBV observed in previous studies of younger women may not occur to the same extent in elderly individuals. © 2015 American Society for Bone and Mineral Research. PMCID: PMC4834704 [Available on 2016-07-01] PMID: 25581217
Bone health is a concern for CR practitioners, since CR practitioners have been shown to have less bone mass (along with less fat and lean mass) than the general population, both in a one-year randomized control trial , and more significantly in a study of a number of us long-term CR practitioners by Luigi Fontana et al. . Fortunately, bone quality does not appear to be compromised in us long-term practitioners . Due to our lower total body mass (hence less force when we fall / crash) but also less fat mass (hence less padding when we fall / crash), it's not clear what the net effect of our thinner but structurally-sound bones is on our risk of fracture. So it was interesting to see that two new meta-analyses in this month's British Medical Journal by the same group of New Zealand researchers addressed the relationship between dietary and supplemental calcium (with or without vitamin D) on bone mineral density (BMD)  and fracture risk . After looking at all the available epidemiological and randomized control trials of the effects of calcium intake on BMD and fracture risk, the authors conclude that: Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD, which are unlikely to lead to a clinically significant reduction in risk of fracture.  and: Dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures. Evidence that calcium supplements prevent fractures is weak and inconsistent.  While  did find supplemental calcium was associated with a small reduction in total and vertebral fractures, there was no reduction in hip or wrist fractures, and some of the included studies were suspect / low quality. When they included only the four most well-conducted randomized control trials in their analysis (which included 44,500 subjects), supplemental calcium didn't reduce total fractures or fractures at any specific site. Overall, it doesn't appear that either dietary or supplemental calcium (with or without vitamin D) will improve our odds of avoiding fractures. At the same time bisphosphonates and other BMD boosting medications have a checkered track record and sometimes serious side effects . So interventions like exercise , maintaining our coordination & balance via activities like yoga and sports, and minimizing risk of traumatic injuries (e.g. by wearing seat belts when driving, helmets when biking, holding handrails when climbing stairs etc.) appear to be the best strategies for keeping our bones safe. --Dean -----------  BMJ 2015; 351 doi: http://dx.doi.org/10.1136/bmj.h4183(Published 29 September 2015) Cite this as: BMJ 2015;351:h4183 Calcium intake and bone mineral density: systematic review and meta-analysis Vicky Tai, William Leung, Andrew Grey, Ian R Reid, Mark J Bolland Abstract Objective To determine whether increasing calcium intake from dietary sources affects bone mineral density (BMD) and, if so, whether the effects are similar to those of calcium supplements. Design Random effects meta-analysis of randomised controlled trials. Data sources Ovid Medline, Embase, Pubmed, and references from relevant systematic reviews. Initial searches were undertaken in July 2013 and updated in September 2014. Eligibility criteria for selecting studies Randomised controlled trials of dietary sources of calcium or calcium supplements (with or without vitamin D) in participants aged over 50 with BMD at the lumbar spine, total hip, femoral neck, total body, or forearm as an outcome. Results We identified 59 eligible randomised controlled trials: 15 studied dietary sources of calcium (n=1533) and 51 studied calcium supplements (n=12 257). Increasing calcium intake from dietary sources increased BMD by 0.6-1.0% at the total hip and total body at one year and by 0.7-1.8% at these sites and the lumbar spine and femoral neck at two years. There was no effect on BMD in the forearm. Calcium supplements increased BMD by 0.7-1.8% at all five skeletal sites at one, two, and over two and a half years, but the size of the increase in BMD at later time points was similar to the increase at one year. Increases in BMD were similar in trials of dietary sources of calcium and calcium supplements (except at the forearm), in trials of calcium monotherapy versus co-administered calcium and vitamin D, in trials with calcium doses of ≥1000 versus <1000 mg/day and ≤500 versus >500 mg/day, and in trials where the baseline dietary calcium intake was <800 versus ≥800 mg/day. Conclusions Increasing calcium intake from dietary sources or by taking calcium supplements produces small non-progressive increases in BMD, which are unlikely to lead to a clinically significant reduction in risk of fracture. -------------  BMJ 2015; 351 doi: http://dx.doi.org/10.1136/bmj.h4580(Published 29 September 2015) Cite this as: BMJ 2015;351:h4580 Calcium intake and risk of fracture: systematic review Mark J Bolland, William Leung, Vicky Tai, Sonja Bastin, Greg D Gamble, Andrew Grey, Ian R Reid Abstract Objective To examine the evidence underpinning recommendations to increase calcium intake through dietary sources or calcium supplements to prevent fractures. Design Systematic review of randomised controlled trials and observational studies of calcium intake with fracture as an endpoint. Results from trials were pooled with random effects meta-analyses. Data sources Ovid Medline, Embase, PubMed, and references from relevant systematic reviews. Initial searches undertaken in July 2013 and updated in September 2014. Eligibility criteria for selecting studies Randomised controlled trials or cohort studies of dietary calcium, milk or dairy intake, or calcium supplements (with or without vitamin D) with fracture as an outcome and participants aged >50. Results There were only two eligible randomised controlled trials of dietary sources of calcium (n=262), but 50 reports from 44 cohort studies of relations between dietary calcium (n=37), milk (n=14), or dairy intake (n=8) and fracture outcomes. For dietary calcium, most studies reported no association between calcium intake and fracture (14/22 for total, 17/21 for hip, 7/8 for vertebral, and 5/7 for forearm fracture). For milk (25/28) and dairy intake (11/13), most studies also reported no associations. In 26 randomised controlled trials, calcium supplements reduced the risk of total fracture (20 studies, n=58 573; relative risk 0.89, 95% confidence interval 0.81 to 0.96) and vertebral fracture (12 studies, n=48 967. 0.86, 0.74 to 1.00) but not hip (13 studies, n=56 648; 0.95, 0.76 to 1.18) or forearm fracture (eight studies, n=51 775; 0.96, 0.85 to 1.09). Funnel plot inspection and Egger’s regression suggested bias toward calcium supplements in the published data. In randomised controlled trials at lowest risk of bias (four studies, n=44 505), there was no effect on risk of fracture at any site. Results were similar for trials of calcium monotherapy and co-administered calcium and vitamin D. Only one trial in frail elderly women in residential care with low dietary calcium intake and vitamin D concentrations showed significant reductions in risk of fracture. Conclusions Dietary calcium intake is not associated with risk of fracture, and there is no clinical trial evidence that increasing calcium intake from dietary sources prevents fractures. Evidence that calcium supplements prevent fractures is weak and inconsistent. -------------  Aging Cell. 2011 Feb;10(1):96-102. doi: 10.1111/j.1474-9726.2010.00643.x. Epub 2010 Nov 15. Reduced bone mineral density is not associated with significantly reduced bone quality in men and women practicing long-term calorie restriction with adequate nutrition. Villareal DT(1), Kotyk JJ, Armamento-Villareal RC, Kenguva V, Seaman P, Shahar A, Wald MJ, Kleerekoper M, Fontana L. Author information: (1)Division of Geriatrics and Nutritional Science, Washington University School of Medicine, 660 S. Euclid Avenue, St. Louis, MO 63110, USA. Calorie restriction (CR) reduces bone quantity but not bone quality in rodents. Nothing is known regarding the long-term effects of CR with adequate intake of vitamin and minerals on bone quantity and quality in middle-aged lean individuals. In this study, we evaluated body composition, bone mineral density (BMD), and serum markers of bone turnover and inflammation in 32 volunteers who had been eating a CR diet (approximately 35% less calories than controls) for an average of 6.8 ± 5.2 years (mean age 52.7 ± 10.3 years) and 32 age- and sex-matched sedentary controls eating Western diets (WD). In a subgroup of 10 CR and 10 WD volunteers, we also measured trabecular bone (TB) microarchitecture of the distal radius using high-resolution magnetic resonance imaging. We found that the CR volunteers had significantly lower body mass index than the WD volunteers (18.9 ± 1.2 vs. 26.5 ± 2.2 kg m(-2) ; P = 0.0001). BMD of the lumbar spine (0.870 ± 0.11 vs. 1.138 ± 0.12 g cm(-2) , P = 0.0001) and hip (0.806 ± 0.12 vs. 1.047 ± 0.12 g cm(-2) , P = 0.0001) was also lower in the CR than in the WD group. Serum C-terminal telopeptide and bone-specific alkaline phosphatase concentration were similar between groups, while serum C-reactive protein (0.19 ± 0.26 vs. 1.46 ± 1.56 mg L(-1) , P = 0.0001) was lower in the CR group. Trabecular bone microarchitecture parameters such as the erosion index (0.916 ± 0.087 vs. 0.877 ± 0.088; P = 0.739) and surface-to-curve ratio (10.3 ± 1.4 vs. 12.1 ± 2.1, P = 0.440) were not significantly different between groups. These findings suggest that markedly reduced BMD is not associated with significantly reduced bone quality in middle-aged men and women practicing long-term calorie restriction with adequate nutrition. PMCID: PMC3607368 PMID: 20969721 ---------------  Arch Intern Med. 2006 Dec 11-25;166(22):2502-10. Bone mineral density response to caloric restriction-induced weight loss or exercise-induced weight loss: a randomized controlled trial. Villareal DT(1), Fontana L, Weiss EP, Racette SB, Steger-May K, Schechtman KB, Klein S, Holloszy JO. Author information: (1)Division of Geriatrics and Nutritional Sciences, Department of Medicine, Washington University School of Medicine, St Louis, MO 63110, USA. firstname.lastname@example.org Erratum in Arch Intern Med. 2007 Mar 12;167(5):452. BACKGROUND: Bone loss often accompanies weight loss induced by caloric restriction (CR), but whether bone loss accompanies similar weight loss induced by exercise (EX) is unknown. We tested the hypothesis that EX-induced weight loss is associated with less bone loss compared with CR-induced weight loss. METHODS: Forty-eight adults (30 women; 18 men; mean +/- SD age, 57 +/- 3 years; and mean +/- SD body mass index, 27 +/- 2 kg/m2) were randomized to 1 of 3 groups for 1 year: CR group (n = 19), regular EX group (n = 19), or a healthy lifestyle (HL) control group (n = 10). Primary outcome measure was change in hip and spine bone mineral density (BMD). Secondary outcomes were bone markers and hormones. RESULTS: Body weight decreased similarly in the CR and EX groups (10.7% +/- 6.3% [-8.2 +/- 4.8 kg] vs 8.4% +/- 6.3% [-6.7 +/- 5.6 kg]; P = .21), whereas weight did not change in the HL group (-1.2% +/- 2.5% [-0.9 +/- 2.0 kg]). Compared with the HL group, the CR group had decreases in BMD at the total hip (-2.2% +/- 3.1% vs 1.2% +/- 2.1%; P = .02) and intertrochanter (-2.1% +/- 3.4% vs 1.7 +/- 2.8%; P = .03). The CR group had a decrease in spine BMD (-2.2% +/- 3.3%; P = .009). Despite weight loss, the EX group did not demonstrate a decrease in BMD at any site. Body weight changes correlated with BMD changes in the CR (R = 0.61; P = .007) but not in the EX group. Bone turnover increased in both CR and EX groups. CONCLUSIONS: CR-induced weight loss, but not EX-induced weight loss, is associated with reductions in BMD at clinically important sites of fracture. These data suggest that EX should be an important component of a weight loss program to offset adverse effects of CR on bone. PMID: 17159017 ----------------  Acta Medica (Hradec Kralove). 2012;55(3):111-5. Bisphosphonate-related osteonecrosis of the jaws. A severe side effect of bisphosphonate therapy. Janovská Z(1). Author information: (1)Department of Dentistry, Charles University in Prague, Faculty of Medicine and University Hospital, Hradec Králové, Czech Republic. email@example.com Bisphosphonates (BP) are potent inhibitors of bone resorption used mainly in the treatment of metastatic bone disease and osteoporosis. By inhibiting bone resorption, they prevent complications as pathological fracture, pain, tumor-induced hypercalcemia. Even though patient's benefit of BP therapy is huge, various side effects may develop. Bisphosphonate-related osteonecrosis of the jaws (BRONJ) is among the most serious ones. Oncologic patients receiving high doses of BP intravenously are at high risk of BRONJ development. BPs impair bone turnover leading to compromised bone healing which may result in the exposure of necrotic bone in the oral cavity frequently following tooth extraction or trauma of the oral mucosa. Frank bone exposure may be complicated by secondary infection leading to osteomyelitis development with various symptoms and radiological findings. In the management of BRONJ, conservative therapy aiming to reduce the symptoms plays the main role. In patients with extensive bone involvement resective surgery may lead to complete recovery, provided that the procedure is correctly indicated. Since the treatment of BRONJ is difficult, prevention is the main goal. Therefore in high risk patients dental preventive measures should be taken prior to bisphosphonate administration. This requires adequate communication between the prescribing physician, the patient and the dentist. PMID: 23297518