Coffee consumption and risk of fractures: a meta-analysis

Increased Osteoblastic and Osteocytic in Vitro Cell Viability by Yerba Mate (Ilex paraguariensis)

BACKGROUND

Yerba mate (YM, Ilex paraguariensis) consumption beneficially affects the bones. However, whether YM components exert their effect on bone cells directly remains elusive.

METHODS

We evaluated how main YM components affect osteoblastic (MC3T3-E1) and osteocytic (MLO-Y4) cells in vitro when administered separately or in an aqueous extract. MC3T3-E1 and MLO-Y4 cells were exposed to three different experimental conditions: (1) Caffeine, chlorogenic acid, and their combinations; (2) Caffeine, rutin, and their combinations; (3) Aqueous YM extract.

RESULTS

All polyphenol and caffeine concentrations as well as that of their tested combinations significantly increased MC3T3-E1 cell viability from 16.6% to 34.8% compared to the control. In MLO-Y4 cells, the lowest rutin and the two highest caffeine concentrations significantly increased cell viability by 11.9, 14.9, and 13.7%, respectively. While rutin and caffeine combinations tended to increase MLO-Y4 cell viability, different chlorogenic acid and caffeine combinations did not affect it. Finally, the aqueous YM extract significantly increased MLO-Y4, MC3T3-E1, and differentiated MC3T3-E1 cell viability compared to the control without treatment.

CONCLUSIONS

YM components (rutin, chlorogenic acid, and caffeine) positively affected bone cells, mainly pre-osteoblast cells. Moreover, the aqueous YM extract significantly increased MLO-Y4, MC3T3-E1, and differentiated MC3T3-E1 cell viabilities indicating an additional relevant nutritional property of YM infusion. Further studies would be required to elucidate the underlying effector mechanism of YM on the bones and its relationship with previously described in vivo positive effects.

The association of coffee consumption with the risk of osteoporosis and fractures: a systematic review and meta-analysis

To elucidate the association of coffee and bone health would help fracture risk reduction via dietary intervention. Although those who had higher coffee consumption were less likely to have osteoporosis, the associations between coffee consumption and fracture risk need further investigations with better study designs.

INTRODUCTION

The associations between coffee consumption and the risk of osteoporosis and fracture remain inconclusive. We aimed to better quantify these associations by conducting meta-analyses of observational studies.

METHODS

Relevant studies were systematically searched on PubMed, Web of Science, Cochrane library, and Embase Database up to November 25, 2021. The odds ratio (OR) or relative risk (RR) with 95% confidence intervals (CI) was pooled and a dose-response analysis was performed.

RESULTS

Four studies with 7114 participants for osteoporosis and thirteen studies with 391,956 participants for fracture incidence were included in the meta-analyses. High versus low coffee consumption was associated with a lower risk of osteoporosis [pooled OR (95% CI): 0.79 (0.65-0.92)], while it was non-significantly associated with fracture incidence [pooled OR (95% CI): 0.86 (0.67-1.05) at hip and 0.89 (0.42-1.36) at non-hip]. A non-linear association between the level of coffee consumption and hip fracture incidence was shown (P = 0.004). The pooled RR (95% CI) of hip fracture risk in those who consumed 1, 2-3, 4, and ≥ 9 cups of coffee per day was 0.92 (0.87-0.97), 0.89 (0.83-0.95), 0.91 (0.85-0.98), and 1.10 (0.76-1.59), respectively. The significance in the association between coffee consumption and the hip fracture incidence decreased in those studies that had larger sample size, higher quality, and more adjustments.

CONCLUSIONS

A dose-dependent relationship may exist between coffee consumption and hip fracture incidence. The effect of high versus low coffee consumption was influenced by study designs. Further studies with dedicated designs are needed to confirm the independent effects of coffee consumption on bone health.

The association between caffeine intake and testosterone: NHANES 2013-2014

Background

Caffeine is one of the most commonly used psychoactive drugs in the world, and provides many health benefits including alertness, improved memory, and reducing inflammation. Despite these benefits, caffeine has been implicated in a number of adverse health outcomes possibly due to effects within the endocrine system, effects that may contribute to impaired reproductive function and low testosterone in men. Previous studies have investigated associations between caffeine consumption and testosterone levels in men, although the quantity and generalizability of these studies is lacking, and the results between studies are conflicting and inconclusive.

Methods

Using data from a cross-sectional study of 372 adult men in the 2013–2014 NHANES survey cycle, the researchers set out to characterize the association between serum testosterone levels, caffeine, and 14 caffeine metabolites.

Results

Multivariable, weighted linear regression revealed a significant inverse association between caffeine and testosterone. Multivariable, linear regression revealed significant, inverse associations between 6 xanthine metabolic products of caffeine and testosterone. Inverse associations were observed between 5-methyluric acid products and testosterone, as well as between 5-acetlyamino-6-amino-3-methyluracil and testosterone. A significant, positive association was observed for 7-methyl xanthine, 3,7-dimethyluric acid, and 7-methyluric acid. Logistic regression models to characterize the association between 2 biologically active metabolites of caffeine (theobromine and theophylline) and odds of low testosterone (< 300 ng/dL) were non-significant.

Conclusions

These findings suggest a potential role for caffeine’s contribution to the etiology of low testosterone and biochemical androgen deficiency. Future studies are warranted to corroborate these findings and elucidate biological mechanisms underlying this association.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-022-00783-z.

Coffee consumption and caffeine intake in relation to risk of fractures: a systematic review and dose-response meta-analysis of observational studies

BACKGROUND

Conflicting reports are available about the association of coffee or caffeine intake and risk of fracture. We performed the current updated systematic review and dose-response meta-analysis of coffee consumption and caffeine intake and risk of fracture to quantify this association.

MATERIALS AND METHODS

PubMed/Medline, ISI Web of Science, and Scopus, Cochrane database were searched up to July 2021. Random-effects model or fixed-effects model was used to pool the study-specific effect sizes (ESs) and 95% confidence intervals (CIs). Dose-response relationship was examined using linear and non-linear dose-response analyses. The certainty of evidence was assessed using NutriGrade tool.

RESULTS

Out of 22 eligible studies included in the meta-analysis, 15 had cohort and 7 had case-control design. We found no significant association between coffee consumption and risk of fracture, either based on pooling cohort (RR: 0.99; 95% CI: 0.88, 1.12; I2 = 71.4%, Pheterogeneity < 0.01) or case-control studies (OR: 1.13; 95% CI: 0.87, 1.46; I2 = 49.0%, Pheterogeneity=0.08). In the subgroup analysis of cohort studies, we observed that higher coffee intake was inversely associated with risk of fracture in men (RR: 0.85; 95% CI: 0.76 to 0.94). In addition, a positive association was seen between coffee consumption and risk of fracture in studies with less than 12 years of follow-up (RR: 1.14; 95% CI: 1.02 to 1.27). With regard to caffeine intake, a statistically significant positive association was seen with risk of fracture (RR: 1.15; 95% CI, 1.08 to 1.23; I2=26.6%, n = 8). In the dose-response analysis, we found that each additional 100 mg caffeine intake was marginally associated with 2% greater risk of fracture (RR: 1.02; 95% CI: 1 to 1.05; I2= 70.3%, n = 6).

CONCLUSION

High coffee consumption was protectively associated with risk of fracture in men, while caffeine intake was positive associated with risk.

The Impact of Lockdowns on Caffeine Consumption: A Systematic Review of the Evidence

The Coronavirus disease 2019 (COVID-19) has been characterized by the World Health Organization as a pandemic in March 2020 and the lockdown measures that were implemented in an effort to limit the transmission of the virus affected the daily life of many people in all over the world. The aim of this systematic review was to investigate the changes during/after the lockdowns in caffeine consumption by coffee and energy drinks. A systematic literature search was conducted in three databases (PubMed, Embase, Web of Science) up to 31 December 2021 and out of 19,511 studies found and 12,885 screened, 16 studies were included according to eligibility criteria. Results regarding coffee consumption showed that a significant part of individuals decreased their consumption and in five studies an increase was reported, including women and seniors >60 years old. Energy drinks were also consumed less during the lockdown compared to the pre-lockdown time. Attention should be given for menopausal women where an increase in coffee consumption was found which could impair bone density, but further research is needed in order to make safe conclusions.

The relationship between healthy lifestyles and bone health: A narrative review

BACKGROUND

Bone health, especially osteoporosis among ageing populations, has become an important topic for both clinical and basic researchers. The relationship between bone health and healthy lifestyles has been frequently discussed. The present study focuses on the relationship between bone health and healthy lifestyles among older adults, based on a global comparison.

METHODS

This narrative review was performed by collecting clinical trials, basic research and reviews on lifestyle and bone health in PubMed database.

RESULTS

Positive effects of physical activity and negative effects of malnutrition, alcohol abuse, and cigarette smoking on bone health were revealed. The relationship between bone health and drinking coffee and tea is still inconclusive. Moreover, the diversity of each region should be aware when considering healthy lifestyles to improve bone health.

CONCLUSION

Healthy lifestyles are highly related to bone health, and different lifestyles may have different influences on regions with a high risk of bone diseases. It is practical to acknowledge the diversity of economic, religious, environmental and geological conditions in each region when providing suitable and effective recommendations for healthy lifestyles that can improve overall bone health.

The importance of the circadian system & sleep for bone health

Adequate sleep timed appropriately during the circadian night is important for numerous biological processes and systems. New evidence suggests that both sleep timing and duration may be important for optimal bone health as well. This review examines the diurnal variation of bone turnover markers (BTMs) and the importance of circadian clock genes in regulating bone mass. In addition, this review explores the evidence for a link between shift work (and its associated disturbances in sleep duration/quality and circadian alignment) and alterations in bone metabolism and bone health. Finally, we review how commonly used medications and over-the-counter substances (e.g. caffeine, melatonin) complicate the relationship between sleep and circadian disorders and bone health.

Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes

Objectives To evaluate the existing evidence for associations between coffee consumption and multiple health outcomes.Design Umbrella review of the evidence across meta-analyses of observational and interventional studies of coffee consumption and any health outcome.Data sources PubMed, Embase, CINAHL, Cochrane Database of Systematic Reviews, and screening of references.Eligibility criteria for selecting studies Meta-analyses of both observational and interventional studies that examined the associations between coffee consumption and any health outcome in any adult population in all countries and all settings. Studies of genetic polymorphisms for coffee metabolism were excluded.Results The umbrella review identified 201 meta-analyses of observational research with 67 unique health outcomes and 17 meta-analyses of interventional research with nine unique outcomes. Coffee consumption was more often associated with benefit than harm for a range of health outcomes across exposures including high versus low, any versus none, and one extra cup a day. There was evidence of a non-linear association between consumption and some outcomes, with summary estimates indicating largest relative risk reduction at intakes of three to four cups a day versus none, including all cause mortality (relative risk 0.83 (95% confidence interval 0.79 to 0.88), cardiovascular mortality (0.81, 0.72 to 0.90), and cardiovascular disease (0.85, 0.80 to 0.90). High versus low consumption was associated with an 18% lower risk of incident cancer (0.82, 0.74 to 0.89). Consumption was also associated with a lower risk of several specific cancers and neurological, metabolic, and liver conditions. Harmful associations were largely nullified by adequate adjustment for smoking, except in pregnancy, where high versus low/no consumption was associated with low birth weight (odds ratio 1.31, 95% confidence interval 1.03 to 1.67), preterm birth in the first (1.22, 1.00 to 1.49) and second (1.12, 1.02 to 1.22) trimester, and pregnancy loss (1.46, 1.06 to 1.99). There was also an association between coffee drinking and risk of fracture in women but not in men.Conclusion Coffee consumption seems generally safe within usual levels of intake, with summary estimates indicating largest risk reduction for various health outcomes at three to four cups a day, and more likely to benefit health than harm. Robust randomised controlled trials are needed to understand whether the observed associations are causal. Importantly, outside of pregnancy, existing evidence suggests that coffee could be tested as an intervention without significant risk of causing harm. Women at increased risk of fracture should possibly be excluded.

Caffeine at a Moderate Dose Did Not Affect the Skeletal System of Rats with Streptozotocin-Induced Diabetes

Diabetes may lead to the development of osteoporosis. Coffee drinking, apart from its health benefits, is taken into consideration as an osteoporosis risk factor. Data from human and animal studies on coffee and caffeine bone effects are inconsistent. The aim of the study was to investigate effects of caffeine at a moderate dose on the skeletal system of rats in two models of experimental diabetes induced by streptozotocin. Effects of caffeine administered orally (20 mg/kg aily for four weeks) were investigated in three-month-old female Wistar rats, which, two weeks before the start of caffeine administration, received streptozotocin (60 mg/kg, intraperitoneally) alone or streptozotocin after nicotinamide (230 mg/kg, intraperitoneally). Bone turnover markers, mass, mineral density, histomorphometric parameters, and mechanical properties were examined. Streptozotocin induced diabetes, with profound changes in the skeletal system due to increased bone resorption and decreased bone formation. Although streptozotocin administered after nicotinamide induced slight increases in glucose levels at the beginning of the experiment only, slight, but significant unfavorable changes in the skeletal system were demonstrated. Administration of caffeine did not affect the investigated skeletal parameters of rats with streptozotocin-induced disorders. In conclusion, caffeine at a moderate dose did not exert a damaging effect on the skeletal system of diabetic rats.

Optimization of roasting conditions through antioxidant and anti-inflammatory activities of Yak-kong (Rhynchosia nulubilis)

The effects of roasting conditions on the antioxidant activities and anti-inflammatory activities of roasted yak-kong were investigated using a second-order central composite design. The optimum conditions for DPPH radical scavenging ability (IC₅₀), ABTS radical scavenging activity (IC₅₀), total phenolic content (TPC), and oxygen radical absorbance capacity (ORAC) were at 111.47°C for 20.45 min, with the best values (DPPH, IC₅₀; 2.143 mg/mL, ABTS, IC₅₀; 1.775 mg/mL, TPC; 51.39mg tannic acid (TAE)/g, and ORAC; 6.89 μmoL trolox equivalents (TE)/g). The optimum conditions of nitric oxide (NO) production, prostaglandin E2 (PGE2) production, and tumor necrosis factor-α (TNF-α) were at 110.24°C for 21.18 min, yielding the best values (NO; 14.484 μM, PGE2; 3.433 mg/mL, and TNF-α; 3.818 ng/mL). Superimposed contour plots with regard to 7 variables indicated that the optimum roasting temperature and time were 110.88°C and 20.86 min. This result suggested that the optimally roasted yak-kong could replace coffee beans to provide potential bone health benefits to heavy coffee drinkers.

Subjective evaluation of the frequency of coffee intake and relationship to osteoporosis in Chinese men

BACKGROUND

The main purpose of this study was to evaluate the associations between frequency of coffee intake and osteoporosis (OP) in a general Chinese male sample.

METHODS

We conducted a large-scale, community-based, cross-sectional study to investigate the associations by using a self-report questionnaire to estimate the frequency of coffee intake. A total of 992 men were available for data analysis in this study. Multiple regression models controlling for confounding factors to include frequency of coffee intake variable were performed to investigate the relationships for OP.

RESULTS

Positive correlations between frequency of coffee intake and T-score were reported (β = 0.211, P = 0.024). Multiple regression analysis indicated that the frequency of coffee intake was significantly associated with OP (P < 0.05 for model 1 and model 2). The men with moderate frequency of coffee intake had a lower prevalence of OP.

CONCLUSIONS

The findings indicated that consumption of coffee was independently and significantly associated with OP. The prevalence of OP was less frequent in Chinese men with moderate coffee intake.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02451397.

Systematic review with meta-analysis: coffee consumption and the risk of cirrhosis

BACKGROUND

Liver cirrhosis is a large burden on global health, causing over one million deaths per year. Observational studies have reported an inverse association between coffee and cirrhosis.

AIMS

To perform a systematic review and meta-analysis to characterise the relationship between coffee consumption and cirrhosis.

METHODS

We searched for studies published until July 2015 that reported odds ratios, relative risks (RR) or hazard ratios for cirrhosis stratified by coffee consumption. We calculated RRs of cirrhosis for an increase in daily coffee consumption of two cups for each study and overall. We performed analyses by study design, type of cirrhosis and mortality. We assessed the risk of bias in each study and the overall quality of evidence for the effect of coffee on cirrhosis.

RESULTS

We identified five cohort studies and four case-control studies involving 1990 cases and 432 133 participants. We observed a dose-response in most studies and overall. The pooled RR of cirrhosis for a daily increase in coffee consumption of two cups was 0.56 (95% CI 0.44-0.68; I(2) 83.3%). The RR pooled from cohort studies for a daily increase of two cups was 0.58 (95% CI 0.41-0.76; I(2) 91.1%) and from case-control studies it was 0.52 (95% CI 0.40-0.63; I(2) 0.0%). The pooled RR of alcoholic cirrhosis for a daily increase of two cups was 0.62 (95% CI 0.51-0.73; I(2) 0%) and of death from cirrhosis it was 0.55 (95% CI 0.35-0.74; I(2) 90.3%).

CONCLUSION

This meta-analysis suggests that increasing coffee consumption may substantially reduce the risk of cirrhosis.

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.

Associations between frequency of coffee consumption and osteoporosis in Chinese postmenopausal women

BACKGROUND

This study was aimed at estimating the associations between coffee intake and osteoporosis (OP) in Chinese postmenopausal women.

METHODS

We conducted a large-scale, community-based, cross-sectional study to investigate the associations by using self-report questionnaire to access frequency of coffee intake. The total of 1817 participants was available to data analysis in this study. Multiple regression models controlling for confounding factors to include frequency of coffee intake variable were performed to investigate the relationships for OP.

RESULTS

Positive correlations between frequency of meat food intake and T-score were reported (β = 0.216, P value < 0.001). Multiple regression analysis indicated that the frequency of meat food intake was significantly associated with OP (P < 0.05 for model 1 and model 2). The postmenopausal women with high frequency of meat food intake had a lower prevalence of OP.

CONCLUSION

The findings indicated that frequency of coffee intake was independently and significantly associated with OP. The prevalence of OP was more frequent in Chinese postmenopausal women not preferring coffee habits.

Effect of coffee intake on hip fracture: a meta-analysis of prospective cohort studies

Several observational studies suggest an association between coffee intake and hip fracture risk. However, the results among them are inconsistent. We aimed to evaluate the association between coffee consumption and risk of hip fracture by performing a meta-analysis of prospective cohort studies. PubMed, Embase, and Web of Science were searched through July 2014 to identify studies that met pre-stated inclusion criterion and reference lists of retrieved articles were reviewed. Information on the characteristics of the included study, risk estimates, and control for possible confounding factors were extracted independently by two authors. A random effects model of meta-analysis was used to calculate the pooled risk estimate. Ten prospective cohort studies involving 5408 patients with hip fracture and 205,930 participants were included in this systematic review. Compared with individuals who did not or seldom drink coffee, the pooled relative risks of hip fracture was 1.13 (95% confidence interval: 0.86 to 1.48) for individuals with the highest coffee consumption. Exception of any single study did not materially alter the combined risk estimate. Visual inspection of funnel plot and Begg’s and Egger’s tests did not indicate evidence of publication bias. In summary, integrated evidence from prospective cohort studies does not suggest a statistically significant association between coffee consumption and risk of hip fracture in developed countries.

Phenotype refinement strengthens the association of AHR and CYP1A1 genotype with caffeine consumption

Two genetic loci, one in the cytochrome P450 1A1 (CYP1A1) and 1A2 (CYP1A2) gene region (rs2472297) and one near the aryl-hydrocarbon receptor (AHR) gene (rs6968865), have been associated with habitual caffeine consumption. We sought to establish whether a more refined and comprehensive assessment of caffeine consumption would provide stronger evidence of association, and whether a combined allelic score comprising these two variants would further strengthen the association. We used data from between 4,460 and 7,520 women in the Avon Longitudinal Study of Parents and Children, a longitudinal birth cohort based in the United Kingdom. Self-report data on coffee, tea and cola consumption (including consumption of decaffeinated drinks) were available at multiple time points. Both genotypes were individually associated with total caffeine consumption, and with coffee and tea consumption. There was no association with cola consumption, possibly due to low levels of consumption in this sample. There was also no association with measures of decaffeinated drink consumption, indicating that the observed association is most likely mediated via caffeine. The association was strengthened when a combined allelic score was used, accounting for up to 1.28% of phenotypic variance. This was not associated with potential confounders of observational association. A combined allelic score accounts for sufficient phenotypic variance in caffeine consumption that this may be useful in Mendelian randomization studies. Future studies may therefore be able to use this combined allelic score to explore causal effects of habitual caffeine consumption on health outcomes.

Coffee consumption and risk of fractures: a systematic review and dose-response meta-analysis

PURPOSE

The data on the association between coffee consumption and the risk of fractures are inconclusive. We performed a comprehensive literature review and meta-analysis to better quantify this association.

METHODS

We identified all potentially relevant articles by searching MEDLINE, EMBASE, Cochrane Library, Web of Science, SCOPUS, and CINAHL (until February 2013). The keywords "coffee," "caffeine," "drink," and "beverage" were used as the exposure factors, and the keyword "fracture" was used as the outcome factor. We determined the overall relative risk (RR) and confidence interval (CI) for the highest and lowest levels of coffee consumption. A dose-response analysis was performed to assess the risk of fractures based on the level of coffee consumption.

RESULTS

We included 253,514 participants with 12,939 fracture cases from 9 cohort and 6 case-control studies. The estimated RR of fractures at the highest level of coffee consumption was 1.14 (95% CI: 1.05-1.24; I(2)=0.0%) in women and 0.76 (95% CI: 0.62-0.94; I(2)=7.3%) in men. In the dose-response analysis, the pooled RRs of fractures in women who consumed 2 and 8 cups of coffee per day were 1.02 (95% CI: 1.01-1.04) and 1.54 (95% CI: 1.19-1.99), respectively.

CONCLUSIONS

Our meta-analysis suggests that daily consumption of coffee is associated with an increased risk of fractures in women and a contrasting decreased risk in men. However, future well-designed studies should be performed to confirm these findings.

Coffee consumption and risk of fracture in the Cohort of Swedish Men (COSM)

Background

Recent research in a large cohort of women showed that coffee consumption is not associated with increased risk of fracture. Whether this is the case also among men is less clear.

Methods

In the Cohort of Swedish Men (COSM) study, 42,978 men aged 45–79 years old at baseline in 1997 answered a self-administered food frequency questionnaire covering coffee consumption and a medical and lifestyle questionnaire covering potential confounders. Our main outcomes first fracture at any site and first hip fracture were collected from the National Patient Registry in Sweden. The association between coffee consumption and fracture risk was investigated using Cox’s proportional hazards regression.

Results

During a mean follow-up of 11.2 years, 5,066 men had a first fracture at any site and of these, 1,186 (23%) were hip fractures. There was no association between increasing coffee consumption (per 200 ml) and rate of any fracture (hazard ratio [HR] 1.00; 95% confidence interval [CI] 0.99–1.02) or hip fracture (HR 1.02; 95% CI 0.99–1.06) after adjustment for potential confounders. For men consuming ≥4 cups of coffee/day compared to those consuming <1 cup of coffee/day, HR for any type of fracture was 0.91 (95% CI 0.80–1.02) and for hip fracture: 0.89 (95% CI 0.70–1.14).

Conclusions

High coffee consumption was not associated with an increased risk of fractures in this large cohort of Swedish men.

Coffee, tea, and the risk of hip fracture: a meta-analysis

The present meta-analysis shows no clear association between coffee consumption and the risk of hip fractures. There was a nonlinear association between tea consumption and the risk of hip fracture. Compared to no tea consumption, drinking 1-4 cups of tea daily was associated with a lower risk of hip fracture.

INTRODUCTION

Prospective cohort and case-control studies have suggested that coffee and tea consumption may be associated with the risk of hip fracture; the results have, however, been inconsistent. We conducted a meta-analysis to assess the association between coffee and tea consumption and the risk of hip fracture.

METHODS

We performed systematic searches using MEDLINE, EMBASE, and OVID until February 20, 2013, without limits of language or publication year. Relative risks (RRs) with 95% confidence intervals (CI) were derived using random-effects models throughout all analyses. We conducted categorical, dose-response, heterogeneity, publication bias, and subgroup analyses.

RESULTS

Our study was based on 195,992 individuals with 9,958 cases of hip fractures from 14 studies, including six cohort and eight case-control studies. The pooled RRs of hip fractures for the highest vs. the lowest categories of coffee and tea consumption were 0.94 (95% CI 0.71-1.17) and 0.84 (95% CI 0.66-1.02), respectively. For the dose-response analysis, we found evidence of a nonlinear association between tea consumption and the risk of hip fracture (p(nonlinearity) < 0.01). Compared to no tea consumption, 1-4 cups of tea per day may reduce the risk of hip fracture by 28% (0.72; 95% CI 0.56-0.88 for 1-2 cups/day), 37% (0.63; 95% CI 0.32-0.94 for 2-3 cups/day), and 21% (0.79; 95% CI 0.62-0.96 for 3-4 cups/day).

CONCLUSIONS

We found no significant association between coffee consumption and the risk of hip fracture. A nonlinear association emerged between tea consumption and the risk of hip fracture; individuals drinking 1-4 cups of tea per day exhibited a lower risk of hip fractures than those who drank no tea. The association between 5 daily cups of tea, or more, and hip fracture risk should be investigated.

Coffee and tea: perks for health and longevity?

PURPOSE OF REVIEW

Tea and coffee, after water, are the most commonly consumed beverages in the world and are the top sources of caffeine and antioxidant polyphenols in the American diet. The purpose of this review is to assess the health effects of chronic tea and/or coffee consumption.

RECENT FINDINGS

Tea consumption, especially green tea, is associated with significantly reduced risks for stroke, diabetes and depression, and improved levels of glucose, cholesterol, abdominal obesity and blood pressure. Habitual coffee consumption in large epidemiological studies is associated with reduced mortality, both for all-cause and cardiovascular deaths. In addition, coffee intake is associated with risks of heart failure, stroke, diabetes mellitus and some cancers in an inverse dose-dependent fashion. Surprisingly, coffee is associated with neutral to reduced risks for both atrial and ventricular arrhythmias. However, caffeine at high doses can increase anxiety, insomnia, calcium loss and possibly the risk of fractures.

SUMMARY

Coffee and tea can generally be recommended as health-promoting additions to an adult diet. Adequate dietary calcium intake may be particularly important for tea and coffee drinkers.

Calcium primer: current controversies and common clinical questions

The use of calcium supplements has recently come under fire because of studies purportedly showing a relationship to cardiovascular events. Although the conclusions made sensational headlines in the popular press, numerous editorials and convincing scientific evidence to the contrary went unnoticed. This controversy and others, such as the relationship of proton-pump inhibitors and osteoporosis, caffeine consumption and the risk of calciuria, and the effects of loop diuretics on fracture risk, are common clinical queries of both primary care physicians and subspecialists. The purpose of this article, therefore, is to provide a concise review of select literature pertinent to current clinical practice and to provide no-nonsense recommendations for common clinical dilemmas regarding calcium supplementation.

Effects of habitual coffee consumption on cardiometabolic disease, cardiovascular health, and all-cause mortality

Coffee, after water, is the most widely consumed beverage in the United States, and is the principal source of caffeine intake among adults. The biological effects of coffee may be substantial and are not limited to the actions of caffeine. Coffee is a complex beverage containing hundreds of biologically active compounds, and the health effects of chronic coffee intake are wide ranging. From a cardiovascular (CV) standpoint, coffee consumption may reduce the risk of type 2 diabetes mellitus and hypertension, as well as other conditions associated with CV risk such as obesity and depression; but it may adversely affect lipid profiles depending on how the beverage is prepared. Regardless, a growing body of data suggests that habitual coffee consumption is neutral to beneficial regarding the risks of a variety of adverse CV outcomes including coronary heart disease, congestive heart failure, arrhythmias, and stroke. Moreover, large epidemiological studies suggest that regular coffee drinkers have reduced risks of mortality, both CV and all-cause. The potential benefits also include protection against neurodegenerative diseases, improved asthma control, and lower risk of select gastrointestinal diseases. A daily intake of ∼2 to 3 cups of coffee appears to be safe and is associated with neutral to beneficial effects for most of the studied health outcomes. However, most of the data on coffee's health effects are based on observational data, with very few randomized, controlled studies, and association does not prove causation. Additionally, the possible advantages of regular coffee consumption have to be weighed against potential risks (which are mostly related to its high caffeine content) including anxiety, insomnia, tremulousness, and palpitations, as well as bone loss and possibly increased risk of fractures.