Potassium salts aid bone health and limit osteoporosis risk, new research finds
Latest research from the University of Surrey has found that the potassium salts (bicarbonate and citrate) plentiful in fruit and vegetables, play an important part in improving bone health. For the first time, the results also showed that these potassium salts reduce bone resorption, the process by which bone is broken down, therefore increasing their strength.
The study, published in the journal Osteoporosis International, also revealed that high intake of potassium salts significantly reduces the excretion of calcium and acid in urine.
“This means that excess acid is neutralised and bone mineral is preserved,” said lead author Dr Helen Lambert from the University of Surrey.
“Excess acid in the body, produced as a result of a typical Western diet high in animal and cereal protein, causes bones to weaken and fracture. Our study shows that these salts could prevent osteoporosis, as our results showed a decrease in bone resorption.”
Although bone resorption and bone formation is a natural process, allowing bones to grow, heal and adapt, in osteoporosis the balance is shifted so that more bone is broken down than is built up, leading to fragility and fractures.
The debilitating disease affects almost three million people in the UK. One in two women and one in five men over the age of 50 will break a bone because of poor bone health.
This study shows that eating more fruits and vegetables could be a way to improve the strength of our bones and prevent osteoporosis.
University of Surrey
Support of joint function, range of motion, and physical activity levels by consumption of a water-soluble egg membrane hydrolyzate
This study evaluated the effects of consumption of hydrolyzed water-soluble egg membrane (WSEM) on joint
function in an otherwise healthy population experiencing chronic pain. A randomized, double-blind, placebo-controlled crossover study included two 4-week periods of placebo and WSEM consumption, separated by a 4-week washout period. Twenty-five study participants were randomized to either the ‘‘placebo-first’’ or ‘‘WSEM first’’ sequence in the crossover trial, and 22 participants completed the study requirements. Range of motion (ROM) was assessed using digital inclinometry for joints associated with vertical weight bearing from neck to knees and for shoulders. Pain at rest and when physically active was scored for the same anatomical areas using visual analog scales (VAS). Physical functioning was tracked using questionnaires with VAS. Consumption of WSEM was associated with improved ROM for neck, spine, hips, and knees, with ROM for the neck and right knee being significantly improved during WSEM consumption compared to placebo (P < .05). ROM improvement for the dominant shoulder was highly significant during WSEM consumption (P< .01). Physical activity levels were significantly higher after WSEM than after placebo consumption (P < .05). Many aspects of physical functioning as part of daily living improved. Subgroup analysis showed rapid improvement of lower back pain after 5 days of WSEM consumption compared to placebo consumption (P < .05) in subjects who participated in the study during the winter season. Daily consumption of 450mg WSEM was associated with improved joint function, comfort during daily activities, and increased physical activity.
Gitte S. Jensen et al., J Med Food 18 (9), 1042–1048 (2015), DOI: 10.1089/jmf.2015.0041
Sleep problems may impact bone health
The daily rhythm of bone turnover is likely important for normal bone health, and recent research suggests that sleep apnea may be an unrecognized cause of some cases of osteoporosis. Sleep apnea's effects on sleep duration and quality, oxygen levels, inflammation, and other aspects of health may have a variety of impacts on bone metabolism.
It's important to determine the relationship between these two increasingly common diseases and to understand the biological processes that may connect them, experts note in a Journal of Bone and Mineral Research review.
"There are strong indications that daily rhythms are an intrinsic and important element of bone biology," said senior author Dr. Eric Orwoll. "If sleep disorders like obstructive sleep apnea affect bone metabolism, they may have diagnostic and therapeutic implications for many patients, including those affected by sleep apnea in their early, bone modeling years," added lead author Dr. Christine Swanson.
Swanson, C. M., et al., (2015), Obstructive Sleep Apnea and Metabolic Bone Disease: Insights Into the Relationship Between Bone and Sleep. J Bone Miner Res, 30: 199–211. doi: 10.1002/jbmr.2446
Product differences in intra-articular hyaluronic acids for osteoarthritis of the knee
Knee osteoarthritis (OA) is a common and often disabling joint disorder among adults that may result in impaired activity and daily function. A variety of treatment options are currently available and prescribed for knee OA depending on the severity of the disorder and physician preference. Intra-articular hyaluronic acid (IA-HA) injection is a treatment for knee OA that reportedly provides numerous biochemical and biological benefits, including shock absorption, chondroprotection, and anti-inflammatory effects within the knee. Clarity is needed as to whether the available IA-HA products should be considered for therapy as a group or whether there are significant differences in the products that need to be considered in treatment of OA of the knee.
A comprehensive literature search of the Medline, EMBASE, and PubMed databases was conducted for all existing randomized trials of IA-HA. The primary outcome measure analyzed was the mean pain score at the reported follow-up nearest to 26 weeks after injection. Pooled efficacy and safety results were recorded for subgroupings of HA product characteristics.
A total of 68 studies were included for analysis. Products with an average molecular weight ≥3000 kDa provided favorable efficacy results when compared with products of an average molecular weight <3000 kDa. Products with a molecular weight ≥3000 kDa demonstrated significantly fewer discontinuations due to treatment-related adverse events than did ≤1500 kDa counterparts, while trial discontinuation rates were similar between biological fermentation-derived HA products and avian-derived HA. The results did not demonstrate a significant difference in the occurrence of effusion across molecular weight subgroups. Additionally, biological fermentation-derived HA had a significantly smaller incidence of effusion than did avian-derived HA. Biological fermentation-derived HA demonstrated fewer acute flare-ups at the injection site than did avian-derived HA products, while high-molecular-weight products demonstrated the highest rate of injection site flare-up.
Despite similarities, IA-HA products should not be treated as a group, as there are differences in IA-HA products that influence both efficacy and safety. In the available literature, IA-HA products with a molecular weight ≥3000 kDa and those derived from biological fermentation relate to superior efficacy and safety-factors that may influence selection an IA-HA product for OA of the knee.
Altman RD et al., Am J Sports Med., 2015, pii: 0363546515609599
The effects of Chamaecyparis obtusa essential oil on pain-related behavior and expression of pro-inflammatory cytokines in carrageenan-induced arthritis in rats
Chamaecyparis obtusa essential oil (COE) has been widely used to treat allergic diseases and was suggested to exert anti-inflammatory, antioxidant, and antimicrobial effects. This study evaluated the effects of COE on pain-related behavior and pro-inflammatory cytokines in rats with carrageenan (CGN)-induced arthritis. Reduced dynamic weight load on inflamed joint in voluntarily walking rats was used as the behavior test for arthritic pain; 10% COE-treated group was significantly attenuated pain (6-8 h post-CGN injection) compared to VEH (mineral oil)-treated group. In addition, the protein levels of interleukin (IL)-1b, tumor necrosis factor-a, IL-6 (6-8 h), and cyclooxygenase (COX)-2 (8 h) within the synovial membrane, as well as IL-1b, COX-2 (6-8 h), and IL-6 (5-7 h) within the meniscus, of 10% COE-treated group were significantly reduced. The current results implicate that COE has anti-inflammatory and anti-nociceptive effects on arthritis in rats.
Suh HR et al., Biosci Biotechnol Biochem, 19, 1-7, 2015
A low-fat yoghurt supplemented with a rooster comb extract on muscle joint function in adults with mild knee pain: a randomized, double blind, parallel, placebo-controlled, clinical trial of efficacy
Preliminary results suggested that oral-administration of rooster comb extract (RCE) rich in hyaluronic acid (HA) was associated with improved muscle strength. Following these promising results, the objective of the present study was to evaluate the effect of low-fat yoghurt supplemented with RCE rich in HA on muscle function in adults with mild knee pain; a symptom of early osteoarthritis. Participants (n = 40) received low-fat yoghurt (125 mL d(-1)) supplemented with 80 mg d(-1) of RCE and the placebo group (n = 40) consumed the same yoghurt without the RCE, in a randomized, controlled, double-blind, parallel trial over 12 weeks. Using an isokinetic dynamometer (Biodex System 4), RCE consumption, compared to control, increased the affected knee peak torque, total work and mean power at 180° s(-1), at least 11% in men (p < 0.05) with no differences in women. No dietary differences were noted. These results suggest that long-term consumption of low-fat yoghurt supplemented with RCE could be a dietary tool to improve muscle strength in men, associated with possible clinical significance. However, further studies are needed to elucidate reasons for these sex difference responses observed, and may provide further insight into muscle function.
Solà R. et al., Food Funct., 6(11), 3531-9, 2015. doi: 10.1039/c5fo00321k
Management of osteoarthritis with avocado/soybean unsaponifiables
Osteoarthritis (OA) is a painful and life-altering disease that severely limits the daily activity of millions of Americans, and is one of the most common causes of disability in the world. With obesity on the rise and the world's population living longer, the prevalence of OA is expected to increase dramatically in the coming decades, generating burdensome socioeconomic costs. This review summarizes current pharmaceutical, non-pharmaceutical, and prospective new treatments for OA, with primary focus on the dietary supplement Avocado/Soybean Unsaponifiables (ASU). ASU modulates OA pathogenesis by inhibiting a number of molecules and pathways implicated in OA. Anticatabolic properties prevent cartilage degradation by inhibiting the release and activity of matrix metalloproteinases (MMP-2,3,13) and increasing tissue inhibitors of these catabolic enzymes (TIMP-1). ASU also inhibits fibrinolysis by stimulating the expression of plasminogen activator inhibitor (PAI-1). Anabolic properties promote cartilage repair by stimulating collagen and aggrecan synthesis via inhibition of inflammatory cytokines such as IL1, IL6, IL8, TNF, ERK, and PGE2. Chondroprotective effects are mediated by correcting growth factor abnormalities, increasing TGFb while decreasing vascular endothelial growth factor (VEGF) in synovial fluid. ASU also inhibits cholesterol absorption and endogenous cholesterol biosynthesis, which mediate reactive oxygen species pathology in chondrocytes. At the clinical level, ASU reduces pain and stiffness while improving joint function, resulting in decreased dependence on analgesics.
Christiansen BA. Et al., Cartilage, 6(1), 30-44, 2015
Are calcium pills any good at preventing bone fractures?
"Calcium supplements don't work, say experts," The Daily Telegraph reports.
While this headline is not strictly true, new research has shown that for most healthy people, calcium supplements will make little difference to your bone health or risk of breaking a bone.
The researchers looked at the best studies they could find that had looked at the relationship between calcium and bone fracture.
For many years, older people have been advised to increase their dietary calcium intake or take a calcium supplement, as calcium is a building block of strong bones. Vitamin D is often recommended alongside calcium, as the body can't absorb calcium without vitamin D.
However, the researchers found that increasing calcium to the high levels recommended in some countries (although not the UK) did not make much difference to the chances of breaking a bone, even when taken alongside vitamin D.
Calcium pills did increase bone strength by about one to two per cent, but the researchers say this is unlikely to make a difference to fracture risk.
Previous studies have shown that calcium supplements may cause side effects, including constipation.
However, there's no need to stop taking calcium and vitamin D supplements if you've been advised to take them by your doctor, as there is little doubt they can help people who are deficient in these nutrients. As for everyone else, it seems that taking these pills is an unnecessary expense.
Where did the story come from?
Both studies were carried out in New Zealand by researchers from the University of Auckland and the University of Otago – plus researchers from the Starship Hospital involved in the bone density study. They were funded by the Health Research Council of New Zealand.
The studies were published in the peer-reviewed British Medical Journal (BMJ) on an open-access basis, so are free to view online.
The main messages of the studies came across in the media reports, although they did not go into detail about the different findings for supplements and dietary calcium, or the problems with some of the studies.
The Mail Online focused on the potential harms of calcium supplements, such as stomach upsets and heart problems, which were not included in this research.
What kind of research was this?
The researchers carried out two systematic reviews. The first looked at the effect of increased calcium on people's bone strength, the second looked at the effect of increased calcium on people's risk of having a fracture.
Systematic reviews are the best way of summarising the evidence on a topic at any one time. However, the results are only as good as the trials done so far.
What did the research involve?
Researchers searched for all the good quality studies they could find that looked at calcium intake and subsequent fracture or bone strength in people over 50.
Where possible, the researchers pooled the results to get an overall answer to the question of whether increasing calcium intake, from pills or food, had an effect on either fracture or bone strength.
The researchers began by looking at randomised controlled trials (RCTs) of increased dietary calcium or calcium supplements (including studies with calcium plus vitamin D). They did not find enough RCTs looking at the effects of dietary calcium on fracture to answer the question, so they also included cohort studies exploring this relationship.
The researchers pooled all the results from RCTs to give an overall figure for the effect of calcium on bone strength, measured as bone mineral density (BMD) and the chances of having any fracture, or a specific fracture of the wrist, hip or spine. They then looked at the range of results to see whether they showed the sort of spread you would expect to see by random chance.
For the cohort studies, the researchers found that the studies didn't report their results in a consistent way. This meant they could not combine the figures in one pooled analysis. Instead, they looked at how many studies reported any effect of increased calcium intake on fracture risk.
What were the basic results?
The researchers found 59 RCTs looking at the effect of calcium on bone mineral density, including 13,790 people. The effect of increased calcium after one year was a 0.6% to 1% increase in BMD.
When they looked at the effects of eating more calcium in the diet, the researchers found 14 out of 22 cohort studies (covering 291,273 people) did not show that calcium had any effect on the chances of breaking any bone. Of those studies that found people with a higher intake of calcium were less likely to have had a fracture, most showed only a small effect.
The 26 RCTs of calcium supplements, which covered 69,107 people, showed a small effect. They appeared to reduce the risk of fractures by 11% (relative risk 0.89, 95% confidence interval 0.81 to 0.96).
However, when they looked at the overall range of results, the researchers said there were more positive results from small studies than you would expect to see by chance. They say this shows evidence of "publication bias", where only positive studies are published and studies with negative outcomes aren't.
They looked at the results again, including only the bigger, more reliable studies. This analysis did not show an overall protective effect from calcium supplements.
Only in one big study of frail elderly women living in nursing homes, who had very low levels of calcium and vitamin D at the outset, did supplements make a difference to the risk of hip fracture.
How did the researchers interpret the results?
The researchers say their results show that increasing calcium in the diet is not likely to decrease risk of broken bones, on current evidence.
They say the benefits found from calcium supplements are small and inconsistent, and "probably have an unfavourable risk benefit profile" given the known side effects of taking calcium.
Talking about the one study that showed a significant reduction in hip fracture, the researchers say this group of elderly women were known to have been deficient in vitamin D, and therefore to have been at higher risk of breaking bones.
They said this study should not be included in the same analyses as other studies of generally healthy people living in the community, nor should it be used to come up with calcium recommendations for the general population.
These two studies pour cold water on the idea that most healthy people aged over 50 need to eat more calcium than they currently do, or that they need to take calcium supplements. They found that, for most people, increased calcium has little effect on bone strength or chances of breaking a bone.
However, the research is based on available studies, of which there were only two small randomised controlled trials with a combined total of 262 people that looked at calcium intake and risk of fracture.
The cohort studies found are not able to show cause and effect as they are subject to confounding, so the combination of these limitations reduces the strength of the results found in this systematic review.
The UK government currently recommends getting 700mg of calcium daily – and says a healthy, varied diet is likely to provide this for most people.
Good sources of dietary calcium include dairy products such as milk, cheese and yoghurt; oily fish such as sardines and anchovies; or nuts and seeds such as almonds and sesame seeds. To get higher levels of calcium, recommended by some organisations, calcium supplements may be needed.
The results of this study suggest most people are unlikely to benefit from taking additional calcium.
We know from previous studies that calcium supplements can have side effects in some people, including constipation and kidney stones. Calcium supplements have also been linked to an increased chance of having a heart attack. You are unlikely to get these side effects from eating a normal amount of calcium as part of a healthy diet.
It's important to remember that most of these studies were looking at generally healthy older people, not people who had a medical reason for taking calcium supplements.
If you've been advised by your doctor to take calcium and vitamin D supplements because you have weak bones (osteoporosis), or because you are deficient in these nutrients, you should continue to take them.