Bone mineral density, polyphenols and caffeine: a reassessment

Indication-Specific Effect of a Phytotherapeutic Remedy on Human Fetal Osteoblastic Cells: An in vitro Analysis

BACKGROUND

Impaired fracture healing is a recurring interdisciplinary medical challenge. Alternative treatment concepts, apart from conventional medicine, are popular, but scientific evidence on their effects is still lacking. Plant-derived substances are widely assumed to support bone homeostasis. To clarify the effects on bone healing mechanisms, a commercially available, homeopathic-spagyric remedy, containing inter alia two herbal substances with assumed osteogenic potential, equisetum arvense and bellis perennis, was analyzed.

METHODS

Human fetal osteoblastic (hFOB) 1.19 cells were incubated with the test substance in serial dilutions from 10 to 0.00001%. Cell viability has been evaluated through ATP level (CTG assay) and MTT tetrazolium reduction. Cell proliferation was analyzed by BrdU incorporation and cell migration by wound healing assay (WHA) via image analysis. Additionally, determination of the expression of key genes via real-time PCR and proteins via proteome array for inflammation, cell proliferation, and angiogenesis were performed.

RESULTS

An incubation of hFOB 1.19 cells with the test substance for 24/72 h showed no reduction in cell number, viability, or proliferation. Cell migration was unimpaired. The test substance induced inflammatory genes and growth factors along with genes of osseous regeneration (ALP, Col1, IL-1α, IL-6, IL-8, IL-10, Osteocalcin, Osteonectin, RUMX2, TGF, VEGFA). Increased protein expression was found in multiple cytokines, chemokines, and acute phase proteins.

CONCLUSION

The test substance did not impair cell vitality parameters (MTT, CTG, BrdU, and WHA). A tendency to activate growth factors, bone regeneration genes, and proteins was shown for osteoblasts, indicating a possible positive effect on osteogenic processes.

Hintergrund

Störungen des komplexen Prozesses der Knochenheilung stellen auch heutzutage noch eine interdisziplinäre Herausforderung dar. Es existieren zahlreiche alternative Therapiekonzepte, deren Evidenz jedoch häufig nicht belegt ist. Es wird davon ausgegangen, dass pflanzliche Substanzen die Knochenheilung unterstützen können. Wir analysierten die Wirkung eines kommerziellen, homeopathisch-spagyrischen Heilmittels, welches unter anderen zwei Pflanzenstoffe enthält, denen ein osteogenes Potential zugeschrieben wird (Equisetum arvense und Bellis perennis).

Methoden

Es erfolgte eine Inkubation humaner fetaler Osteoblastenzellen (hFOB 1.19) mit der Testsubstanz in absteigender Verdünnung von 10 bis 0.00001%. Die Zellvitalität wurde anhand der Zellzahlbestimmung durch ATP-abhängige metabolische Aktivität mittels CellTiter-Glo® (CTG) Test sowie durch Tetrazolium Reduktion (MTT) evaluiert. Die Zellproliferation wurde durch Inkorporation von Bromdesoxyuridin (BrdU) in die DNA aktiver Zellen analysiert. Der Wound Healing Assay (WHA) diente der Quantifizierung der Zellmigration. Zusätzlich wurde die Expression bestimmter Schlüsselgene mittels real-time PCR und die Proteinexpression via proteom array für Inflammation, Zellproliferation und Angiogenese erhoben.

Ergebnisse

Die Inkubation von hFOB 1.19 mit der Testsubstanz für 24/72 Stunden führte zu keiner Reduktion von Zellzahl, -vitalität oder -proliferation. Auch die Zellmigration war unbeeinträchtigt. Es zeigte sich eine Induktion inflammatorischer Gene, Wachstumsfaktoren sowie Genen der knöchernen Regeneration (ALP, Col1, IL-1α, IL-6, IL-8, IL-10, Osteocalcin, Osteonectin, RUMX2, TGF, VEGFA). Verschiedene Zytokine, Chemokine und Akute Phase Proteine wurden vermehrt exprimiert.

Schlussfolgerung

Die Testsubstanz hatte keine negativen Auswirkungen auf die gemessenen Zellvitalitätsparameter (MTT, CTG, BrdU and WHA). Es zeigte sich eine Aktivierungstendenz für Wachstumsfaktoren, Gene und Proteine der Knochenregeneration, die auf einen möglichen positiven Effekt der Substanz auf den Prozess des Knochenheilung hinweisen.

Hyperparathyroidism, Serum Phosphorus and Dietary Intake in Hemodialysis Patients: Is There a Novel Relationship?

The management of hyperparathyroidism (intact parathyroid hormone (iPTH) serum levels > 585 pg/mL), frequently focuses on the appropriate control of mineral and bone markers, with the decrease in serum and dietary phosphorus as two of the targets. We aimed to investigate the association between iPTH, serum phosphorus levels and dietary intake. This was a cross-sectional, multicenter, observational study with 561 patients on hemodialysis treatment. Clinical parameters, body composition and dietary intake were assessed. For the analysis, patients were divided into three groups: (a) iPTH < 130, (b) iPTH between 130 and 585 and (c) iPTH > 585 pg/mL. The association between PTH, serum phosphorus and dietary intake was analyzed using linear regression models. In the whole sample, 23.2% of patients presented an iPTH > 585 pg/mL. Patients with higher iPTH levels were those with longer HD vintage and lower ages, higher serum phosphorus, serum calcium, Ca/P product, albumin and caffeine intake, and a lower dietary intake of phosphorus, fiber, riboflavin and folate. Higher serum phosphorus predicted higher iPTH levels, even in the adjusted model. However, lower dietary phosphorus and fiber intake were predictors of higher iPTH levels, including in the adjusted model. Our results bring new data to the relationship between dietary intake and iPTH values. Despite higher serum phosphorus being observed in patients with HPTH, an opposite association was noted regarding dietary phosphate and fiber.

Soft drinks, tea and coffee consumption in relation to risk of fracture: evidence from china health and nutrition survey

INTRODUCTION

To investigate the association between soft drinks, tea and coffee consumption, and risk of fracture in the China Health and Nutrition Survey.

MATERIALS AND METHODS

A cross-sectional study with multi-stage random cluster sampling was conducted in nine Chinese provinces in 2004, 2006, 2009 and 2011. A total of 36,740 participants were included the data analyses. Self-administered questionnaires and physical examinations provided data on beverages consumption, fracture history, and other potential risk factors. Binary logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for potentially confounding variables.

RESULTS

The prevalence of fracture increased over the 7-year period of the surveys, with 1833 (5.3%) participants reporting a fracture history. Soft drink consumption increased over this time period, and tea consumption was relatively stable, whereas coffee consumption tended to increase sharply. Consumers of soft drinks ≥ 3 times/week (versus never) had a higher risk of fracture (OR = 1.86, 95% CI = 1.43-2.32, p < 0.001, p for trend = 0.039). Consumers of tea ≥ 5 cups/day (versus never) also had a higher risk of fracture (OR = 1.21, 95% CI = 1.09-1.45, p = 0.028, p for trend < 0.001). Similarly, consumers of coffee ≥ 2 cups/day (versus never) had a higher risk of fracture (OR = 1.84, 95% CI = 1.01-3.34, p = 0.045, p for trend = 0.002). Subgroup analyses by gender suggested that coffee consumption increased risk of fracture in females (OR = 1.84, 95% CI = 1.32-2.63, p = 0.001).

CONCLUSION

Our findings suggest that high consumption of soft drinks, tea and coffee is associated with an increased risk of fracture in the Chinese population. Which has important public health implications given the widespread consumption of these beverages.

Association of Coffee and Tea Intake with Bone Mineral Density and Hip Fracture: A Meta-Analysis

Background and Objectives: Osteoporosis is characterized by low bone mass and high bone fragility. Findings regarding the association of coffee and tea intake with osteoporosis have been inconsistent. We conducted this meta-analysis to investigate whether coffee and tea intake is associated with low bone mineral density (BMD) and high hip fracture risk. Materials and Methods: PubMed, MEDLINE, and Embase were searched for relevant studies published before 2022. Studies on the effects of coffee/tea intake on hip fracture/BMD were included in our meta-analysis, whereas those focusing on specific disease groups and those with no relevant coffee/tea intake data were excluded. We assessed mean difference (MD; for BMD) and pooled hazard ratio (HR; for hip fracture) values with 95% confidence interval (CI) values. The cohort was divided into high- and low-intake groups considering the thresholds of 1 and 2 cups/day for tea and coffee, respectively. Results: Our meta-analysis included 20 studies comprising 508,312 individuals. The pooled MD was 0.020 for coffee (95% CI, -0.003 to 0.044) and 0.039 for tea (95% CI, -0.012 to 0.09), whereas the pooled HR was 1.008 for coffee (95% CI, 0.760 to 1.337) and 0.93 for tea (95% CI, 0.84 to 1.03). Conclusions: Our meta-analysis results suggest that daily coffee or tea consumption is not associated with BMD or hip fracture risk.

Assessing the Association between Important Dietary Habits and Osteoporosis: A Genetic Correlation and Two-Sample Mendelian Randomization Study

Objective: Osteoporosis (OP) is the most common bone disease. The genetic and metabolic factors play important roles in OP development. However, the genetic basis of OP is still elusive. The study aimed to explore the relationships between OP and dietary habits. Methods: This study used large-scale genome-wide association study (GWAS) summary statistics from the UK Biobank to explore potential associations between OP and 143 dietary habits. The GWAS summary data of OP included 9434 self-reported OP cases and 444,941 controls, and the GWAS summary data of the dietary habits included 455,146 participants of European ancestry. Linkage disequilibrium score regression (LDSC) was used to detect the genetic correlations between OP and each of the 143 dietary habits, followed by Mendelian randomization (MR) analysis to further assess the causal relationship between OP and candidate dietary habits identified by LDSC. Results: The LDSC analysis identified seven candidate dietary habits that showed genetic associations with OP including cereal type such as biscuit cereal (coefficient = −0.1693, p value = 0.0183), servings of raw vegetables per day (coefficient = 0.0837, p value = 0.0379), and spirits measured per month (coefficient = 0.115, p value = 0.0353). MR analysis found that OP and PC17 (butter) (odds ratio [OR] = 0.974, 95% confidence interval [CI] = (0.973, 0.976), p value = 0.000970), PC35 (decaffeinated coffee) (OR = 0.985, 95% CI = (0.983, 0.987), p value = 0.00126), PC36 (overall processed meat intake) (OR = 1.035, 95% CI = (1.033, 1.037), p value = 0.000976), PC39 (spirits measured per month) (OR = 1.014, 95% CI = (1.011, 1.015), p value = 0.00153), and servings of raw vegetables per day (OR = 0.978, 95% CI = (0.977, 0.979), p value = 0.000563) were clearly causal. Conclusions: Our findings provide new clues for understanding the genetic mechanisms of OP, which focus on the possible role of dietary habits in OP pathogenesis.

Habitual caffeine intake affects implant osseointegration: An in vivo study

OBJECTIVES

This study aimed to evaluate the effect of habitual caffeine (CAF) intake on stability, bone regeneration, and expression of bone markers at the bone-implant interface.

BACKGROUND

Studies show that habitual CAF alters bone health and remodeling. Yet, there is no information regarding CAF effects on osseointegration of bone-anchored implants.

METHODS

Wistar rats were divided into two groups: one received tap drinking water alone (control) and the other received tap water with CAF (300 mg/L). After 12 weeks, their tibiae received screw-shaped titanium implants. After another 12 weeks, CAF (n = 5) and control (n = 5) animals were sacrificed and the implant stability was evaluated using a removal torque (RTQ) device. Thereafter, the implants were processed for gene expression analysis, and the implantation sites were harvested for histology. Implants with the surrounding bone were dissected en bloc and subjected to micro-computed tomography (micro-CT).

RESULTS

The results showed that implants in the CAF group had an 87% significant increase in RTQ compared to the control. Further, micro-CT revealed a higher proportion of mineralized bone filling the implant threads in the CAF group. The molecular analysis indicated higher expression of bone formation (ALP), remodeling (CatK), and vascularization (VEGF) genes in implant-adherent cells in the CAF group. Histology suggested increased vascularity in the tissue surrounding the implant in the CAF group.

CONCLUSIONS

Within the limit of this study, it is concluded that habitual CAF intake conveys a positive, promoting effect on long-term osseointegration. Clinical studies are worth pursuing to verify this experimental observation.

Effects of Yerba Mate (IIex paraguariensis) on Histomorphometry, Biomechanics, and Densitometry on Bones in the Rat

Yerba mate (Ilex paraguariensis) is a xanthine-containing beverage, which is also rich in caffeine. Because caffeine has a negative impact on bone mineral density (BMD) mainly associated with low calcium (Ca) diets, there would be expected a negative effect of yerba mate on bone. In this study, Sprague-Dawley rats were used and randomly assigned into four groups (n = 6/group): Control + Ca 0.2 g %; Control + Ca 0.9 g %; Yerba + Ca 0.2 g %; Yerba + Ca 0.9 g %. At the end of the experiment, tibias and femurs were obtained for BMD, morphometric, histomorphometric, and biomechanical analyses. While there was no difference in bone parameters between rats with and without yerba mate consumption, a negative effect of low Ca diet was observed in BMD, morphometric, histomorphometric, and biomechanical results. Interaction between Ca content in the diet and yerba mate was only found in trabecular bone volume, which would indicate that the negative effect of low Ca intake on bone volume is reversed in part by yerba mate infusion. However, yerba mate was not able to reverse the negative effect of low Ca content on biomechanical properties and trabecular connectivity. In summary, at least in our study, yerba mate would not have a negative effect on bone and would be safe for the bone health of consumers.

Dietary patterns and bone mineral density in Brazilian postmenopausal women with osteoporosis: a cross-sectional study

BACKGROUND/OBJECTIVES

The aim of this study was to investigate the association between dietary patterns and bone mineral density (BMD) in postmenopausal women with osteoporosis.

SUBJECTS/METHODS

This cross-sectional study included 156 postmenopausal and osteoporotic Brazilian women aged over 45 years. BMD of lumbar spine, total femur (TF), femoral neck and of total body (TB), as well as body composition (fat and lean mass), was assessed by dual-energy X-ray absorptiometry. Body mass index and lifestyle information were also obtained. Dietary intake was assessed by using a 3-day food diary. Dietary patterns were obtained by principal component factor analysis. Adjusted multiple linear regression analysis was applied in order to evaluate the predictive effect of dietary patterns on BMD. Significance was set at P<0.05.

RESULTS

Five patterns were retained: 'healthy', 'red meat and refined cereals', 'low-fat dairy', 'sweet foods, coffee and tea' and 'Western'. The 'sweet foods, coffee and tea' pattern was inversely associated with TF BMD (β=-0.178; 95% CI: -0.039 to -0.000) and with TB BMD (β=-0.320; 95% CI: -0.059 to -0.017) even after adjusting for energy and calcium intake, lean mass, age and postmenopausal time.

CONCLUSIONS

A concomitant excessive consumption of sweet foods and caffeinated beverages appears to exert a negative effect on BMD even when the skeleton already presents some demineralization. Food and beverage intake is a modifiable factor that should not be neglected in the treatment of individuals with osteoporosis.

Tea consumption didn't modify the risk of fracture: a dose-response meta-analysis of observational studies

Background

Fractures are important causes of healthy damage and economic loss nowadays. The conclusions of observational studies on tea consumption and fracture risk are still inconsistent. The objective of this meta-analysis is to determine the effect of tea drinking on the risk of fractures.

Methods

A comprehensive literature search was conducted in PubMed, Embase and reference lists of the relevant articles. Observational studies that reported an estimate of the association between tea drinking and incidence of fractures were included. A meta-analysis was conducted by the STATA software.

Results

A total of 9 studies involving 147,950 individuals that examined the association between tea consumption and risk of fractures were included in this meta-analysis. The odds risks (ORs) with 95% confidence intervals (CIs) were pooled using a random-effects model. The pooled OR of 9 observational studies for the tea consumption on risk of fracture was 0.89 (95% CI, 0.78-1.04). In the subgroup analyses, no significant association was detected in neither cohort studies (n = 3; OR, 0.97; 95% CI, 0.89-1.06) nor case–control studies (n = 6; OR, 0.91; 95% CI, 0.70-1.19), respectively. No significant association was detected in the dose–response meta-analysis.

Conclusions

Tea consumption might not be associated with the risk of fractures. The following large-sample and well-designed studies are required to confirm the existing conclusions.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/5309904231178427.

Inhibition of parathyroid hormone secretion by caffeine in human parathyroid cells

CONTEXT AND OBJECTIVE

Caffeine is a highly consumed psychoactive substance present in our daily drinks. Independent studies have reported associations between caffeine consumption, low bone mineral density, and urinary calcium loss, as well as impaired bone development in vitro and in vivo. Calcium (Ca(2+)), vitamin D, and PTH are critical regulators of bone remodeling. A possible association between caffeine and parathyroid gland function has been suggested in the literature.

DESIGN, SETTING, AND PATIENTS

Effects of caffeine on PTH secretion and Ca(2+) levels were determined by batch incubation and Fura-2, respectively, in pathological parathyroid cells. Protein expressions were studied by Western blot and immunohistochemistry in normal and parathyroid adenoma tissues. Alterations in gene expressions of adenosine receptor A1 (ADORA1) and A2 (ADORA2A) and PTH were quantified by PCR; intracellular cAMP levels and protein kinase A activity were analyzed by an antibody-based assay.

RESULTS

We studied physiological concentrations of caffeine ranging from 1 to 50 μm and found that 50 μm caffeine caused a significant decrease of PTH secretion and PTH gene expression. This decrease occurred in parallel with a decrease of the intracellular cAMP level, protein kinase A activity, and ADORA1 gene expression, indicating a possible causal relationship. The intracellular level of Ca(2+) was unaffected even by high concentrations of caffeine. Protein expressions demonstrated two main targets for caffeine-ADORA1 and ADORA2A.

CONCLUSION

A physiological high dose of caffeine inhibits PTH secretion in human parathyroid cells, possibly due to a decrease of the intracellular level of cAMP. The observation demonstrates a functional link between caffeine and parathyroid cell function.

Inhibition of human in vitro osteoclastogenesis by Equisetum arvense

OBJECTIVES

Equisetum arvense has long been used in traditional medicines to treat different disorders, including bone pathologies. In this study a hydromethanolic extract of E. arvense was assessed for its effects on human osteoclastogenesis.

MATERIALS AND METHODS

Osteoclast precursors were maintained in non-stimulated and stimulated (presence of M-CSF and RANKL) conditions, or in co-cultures with osteoblasts. Cell cultures were treated with 0.00016-0.5 mg/ml of a hydromethanolic E. arvense extract.

RESULTS

The extract did not affect spontaneous osteoclastogenesis. In osteoclast precursors committed to osteoclastogenesis (stimulated or co-cultured with osteoblasts), E. arvense caused dose-dependent inhibitory effect that became statistically significant at concentrations ≥0.004 mg/ml. This was observed using different osteoclast differentiation and activation markers. Cell response was associated with changes in relative contribution of MEK and NFkB signalling pathways, as well as PGE2 production. As there were differences in the response of osteoclast precursors maintained in the presence of inductive factors, or co-cultured with osteoblastic cells, it seems that E. arvense extract had the ability to modulate osteoclastogenesis, either by acting directly on osteoclast precursor cells, and/or via osteoblasts.

CONCLUSIONS

Equisetum appeared to have a negative effect on human osteoclastogenesis, which is in line with its putative beneficial role in pathophysiological conditions associated with increased osteoclastic activity, and might suggest potential utility for treatment with bone regeneration strategies.

Assessing caffeine intake in the United Kingdom diet

Caffeine occurs naturally in the leaves and seeds of many plants and is artificially added to some beverages. Consumption of caffeine has been linked to both positive and adverse health outcomes. We incorporated estimates of caffeine content (mg/100g or ml) of foods and drinks, taken from the published literature, to provide a preliminary estimate of caffeine intake for the UK population, based on data collected in the National Diet and Nutrition Survey 2008-10. Among consumers mean total caffeine intakes of adult men 19+ y were significantly greater than intakes by boys 4-10y and 11-18y (p<0.05), with the same age-related differences seen for females. 4.1% of men 19+ y and 3.8% of women 19+ y had caffeine intakes in excess of 300mg/d. The addition of caffeine to UK food composition databases will allow more detailed study of the health effects of caffeine consumption.

Equisetum arvense hydromethanolic extracts in bone tissue regeneration: in vitro osteoblastic modulation and antibacterial activity

OBJECTIVES

Equisetum arvense preparations have long been used to promote bone healing. The aim of this work was to evaluate osteogenic and antibacterial effects of E. arvense hydromethanolic extracts.

MATERIALS AND METHODS

Dried aerial components of E. arvense were extracted using a mixture of methanol:water (1:1), for 26 days, yielding three extracts that were tested (10-1000 μg/ml) in human osteoblastic cells: E1, E2 and EM (a mixture of E1 and E2, 1:1). Cell cultures, performed on cell culture plates or over hydroxyapatite (HA) substrates, were assessed for osteoblastic markers. In addition, effects of the extracts on Staphylococcus aureus were addressed.

RESULTS

Solution E1 caused increased viability/proliferation and ALP activity at 50-500 μg/ml, and deleterious effects at levels ≥1000 μg/ml. E2 inhibited cell proliferation at levels ≥500 μg/ml. EM presented a profile between those observed with E1 and E2. In addition, E1, E2 and EM, 10-1000 μg/ml, inhibited expansion of S. aureus. Furthermore, E1, tested in HA substrates colonized with osteoblastic cells, causing increase in cell population growth (10-100 μg/ml). E1 also exhibited antibacterial activity against S. aureus cultured over HA.

CONCLUSIONS

Results showed that E. arvense extracts elicited inductive effects on human osteoblasts while inhibiting activity of S. aureus, suggesting a potentially interesting profile regarding bone regeneration strategies.

Yerba Mate (Ilex paraguariensis) consumption is associated with higher bone mineral density in postmenopausal women

Yerba Mate (Ilex paraguariensis) tea consumption is higher in Argentina and other South American countries than those of coffee or tea (Camellia sinensis). The effects of Yerba Mate on bone health have not previously been explored. From a program for osteoporosis prevention and treatment, postmenopausal women who drank at least 1 L of Yerba Mate tea daily during 4 or more years (n=146) were identified, and matched by age and time since menopause with an equal number of women who did not drink Yerba Mate tea. Their bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry (DXA) at the lumbar spine and femoral neck. Yerba Mate drinkers had a 9.7% higher lumbar spine BMD (0.952 g/cm(2) versus 0.858 g/cm(2): p<0.0001) and a 6.2% higher femoral neck BMD (0.817 g/cm(2) versus 0.776 g/cm(2); p=0.0002). In multiple regression analysis, Yerba Mate drinking was the only factor, other than body mass index, which showed a positive correlation with BMD at both the lumbar spine (p<0.0001) and the femoral neck (p=0.0028). Results suggest a protective effect of chronic Yerba Mate consumption on bone.

Review of the efficacy of green tea, isoflavones and aloe vera supplements based on randomised controlled trials

We assess the evidence for health benefits of three commonly consumed plant food supplements (PFS), green tea, isoflavone and aloe vera, based on published systematic reviews of randomised controlled trials (RCTs). Whilst the potential benefits of green tea have been reported in a wide range of health areas, it is only in the area of the metabolic syndrome that the number of RCTs is approaching sufficient to judge such efficacy. Isoflavone supplements are widely used, and RCTs indicate that they affect bone resorption at lower doses in postmenopausal women undergoing estrogen-related bone loss, but this is only translated to attenuation of bone loss at higher doses of isoflavones. A systematic review on RCTs concluded that the effects of isoflavones on hot flashes in postmenopausal women were highly variable and no conclusions could be drawn. Despite the popularity of aloe vera as a PFS, the evaluation of its efficacy as a coadjuvant therapy for certain metabolic or digestive pathologies remains scarce; it constitutes a typical example of a naturally occurring ingredient whose efficacy in topical applications presupposes its efficacy in systemic applications. Nevertheless, its possible toxic effects on oral consumption call for caution in its utility as a PFS. Since 2007, efficacy evaluation of PFS in Europe has been covered by European Union Nutrition and Health Claims legislation. The European Food Safety Authority has adopted an approach relying on RCTs, while medicinal effects are accepted based on traditional use. In general, there are insufficient RCTs for claims to be made, and conclusive results on PFS should be obtained in the future by conducting studies with more homogeneous populations, by using supplements with optimised and measured bioavailability, and by conducting larger RCTs.