Dietary calcium intake and hypertension risk: a dose-response meta-analysis of prospective cohort studies

Na and K Intake from Lunches Served in a Japanese Company Cafeteria and the Estimated Improvement in the Dietary Na/K Ratio Using Low-Na/K Seasonings and Dairy to Prevent Hypertension

The excessive intake of sodium (Na) and insufficient intake of potassium (K) are major concerns in the prevention of hypertension. Using low-Na/K seasonings (reducing 25% of the NaCl and adding K salt) may improve the dietary Na/K ratio and help prevent hypertension. To devise an intervention study using low-Na/K seasonings at a company cafeteria, we calculated the Na and K contents of the meals served at the cafeteria and estimated changes in the intakes when suitable low-Na/K seasonings were used. We also considered using milk as a good source of K. We used an ingredient list of a company cafeteria and calculated Na and K contents in each dish. The average amounts of NaCl and K per use were 5.04 g and 718 mg, respectively. Seasonings contributed 70.9% of the NaCl. With the use of low-Na/K seasonings, an estimated reduction in NaCl of 0.8 g/day and an estimated increase in K of 308 mg/day was achieved. With an additional serving (200 mL) of milk, NaCl was reduced by 0.57 g/day and K was increased by 610 mg/day, with an overall decrease in the dietary Na/K ratio from 3.20 to 2.40. The use of low-Na/K seasonings and dairy may improve the dietary Na/K ratio among cafeteria users and help prevent hypertension.

A cross-sectional analysis of the PURE study on minerals intake among Malaysian adult population with hypertension

Hypertension (HPT) is the leading modifiable risk factor for cardiovascular diseases and premature death worldwide. Currently, attention is given to various dietary approaches with a special focus on the role of micronutrient intake in the regulation of blood pressure. This study aims to measure the dietary intake of selected minerals among Malaysian adults and its association with HPT. This cross-sectional study involved 10,031 participants from the Prospective Urban and Rural Epidemiological study conducted in Malaysia. Participants were grouped into HPT if they reported having been diagnosed with high blood pressure [average systolic blood pressure (SBP)/average diastolic blood pressure (DBP) ≥ 140/90 mm Hg]. A validated food frequency questionnaire (FFQ) was used to measure participants' habitual dietary intake. The dietary mineral intake of calcium, copper, iron, magnesium, manganese, phosphorus, potassium, sodium, and zinc was measured. The chi-square test was used to assess differences in socio-demographic factors between HPT and non-HPT groups, while the Mann-Whitney U test was used to assess differences in dietary mineral intake between the groups. The participants' average dietary intake of calcium, copper, iron, magnesium, manganese, phosphorus, potassium, selenium, sodium, and zinc was 591.0 mg/day, 3.8 mg/day, 27.1 mg/day, 32.4 mg/day, 0.4 mg/day, 1431.1 mg/day, 2.3 g/day, 27.1 µg/day, 4526.7 mg/day and 1.5 mg/day, respectively. The intake was significantly lower among those with HPT than those without HPT except for calcium and manganese. Continuous education and intervention should be focused on decreasing sodium intake and increasing potassium, magnesium, manganese, zinc, and calcium intake for the general Malaysian population, particularly for the HPT patients.

Planting the Seed for Blood Pressure Control: The Role of Plant-Based Nutrition in the Management of Hypertension

PURPOSE OF REVIEW

Hypertension results in significant morbidity, mortality, and healthcare expenditures. Fortunately, it is largely preventable and treatable by implementing dietary interventions, though these remain underutilized. Here, we aim to explore the role of healthy dietary patterns in hypertension management and describe approaches for busy clinicians to address nutrition effectively and efficiently with patients.

RECENT FINDINGS

DASH, Mediterranean, vegetarian, and vegan diets that include minimally processed, plant-based foods as core elements have consistently shown positive effects on hypertension. Recommendations that distill the most healthful components of these diets can significantly impact patient outcomes. Clinicians can harness evidence-based dietary assessment and counseling tools to implement and support behavioral changes, even during brief office visits. Healthful plant-based dietary patterns can often effectively prevent and treat hypertension. Clinicians may help improve patient outcomes by discussing evidence-based nutrition with their patients. Future work to promote infrastructural change that supports incorporating evidence-based nutrition into medical education, clinical care, and society at large can support these efforts.

Association between dietary calcium intake and severe abdominal aorta calcification among American adults: a cross-sectional analysis of the National Health and Nutrition Examination Survey

BACKGROUND

Evidence regarding the relationship between dietary calcium intake and severe abdominal aortic calcification (AAC) is limited. Therefore, this study aimed to investigate the association between dietary calcium intake and severe AAC in American adults based on data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

The present cross-sectional study utilized data from the NHANES 2013-2014, a population-based dataset. Dietary calcium intake was assessed using two 24-h dietary recall interviews. Quantification of the AAC scores was accomplished utilizing the Kauppila score system, whereby severe AAC was defined as having an AAC score greater than 6. We used multivariable logistic regression models, a restricted cubic spline analysis, and a two-piecewise linear regression model to show the effect of calcium intake on severe AAC.

RESULTS

Out of the 2640 individuals examined, 10.9% had severe AAC. Following the adjustment for confounding variables, an independent association was discovered between an augmented intake of dietary calcium and the incidence of severe AAC. When comparing individuals in the second quartile (Q2) of dietary calcium intake with those in the lowest quartile (Q1), a decrease in the occurrence of severe AAC was observed (odds ratio: 0.66; 95% confidence interval: 0.44-0.99). Furthermore, the relationship between dietary calcium intake and severe AAC demonstrated an L-shaped pattern, with an inflection point observed at 907.259 mg/day. Subgroup analyses revealed no significant interaction effects.

CONCLUSION

The study revealed that the relationship between dietary calcium intake and severe AAC in American adults is L-shaped, with an inflection point of 907.259 mg/day. Further research is required to confirm this association.

The Role of Diet in the Prevention of Hypertension and Management of Blood Pressure: An Umbrella Review of Meta-Analyses of Interventional and Observational Studies

High blood pressure (BP) is a major pathological risk factor for the development of several cardiovascular diseases. Diet is a key modifier of BP, but the underlying relationships are not clearly demonstrated. This is an umbrella review of published meta-analyses to critically evaluate the wide range of dietary evidence from bioactive compounds to dietary patterns on BP and risk of hypertension. PubMed, Embase, Web of Science, and Cochrane Central Register of Controlled Trials were searched from inception until October 31, 2021, for relevant meta-analyses of randomized controlled trials or meta-analyses of observational studies. A total of 175 publications reporting 341 meta-analyses of randomized controlled trials (145 publications) and 70 meta-analyses of observational studies (30 publications) were included in the review. The methodological quality of the included publications was assessed using Assessment of Multiple Systematic Reviews 2 and the evidence quality of each selected meta-analysis was assessed using NutriGrade. This umbrella review supports recommended public health guidelines for prevention and control of hypertension. Dietary patterns including the Dietary Approaches to Stop Hypertension and the Mediterranean-type diets that further restrict sodium, and moderate alcohol intake are advised. To produce high-quality evidence and substantiate strong recommendations, future research should address areas where the low quality of evidence was observed (for example, intake of dietary fiber, fish, egg, meat, dairy products, fruit juice, and nuts) and emphasize focus on dietary factors not yet conclusively investigated.

Association between dairy intake and risk of incident dementia: the Ohsaki Cohort 2006 Study

PURPOSE

To investigate the association between dairy intake and risk of incident dementia in older adults.

METHODS

A longitudinal analysis of dairy intake with incident dementia was conducted using a cohort study of 11,637 non-disabled Japanese older adults aged ≥ 65 years followed-up for up to 5.7 years (mean: 5.0 years). Data on milk, yogurt, and cheese intake were collected using a validated food frequency questionnaire. Total dairy intake was calculated as the sum of the daily intake of milk, yogurt, and cheese, which was sex-specifically categorized in quintiles. Dementia cases were retrieved from the public long-term care insurance database. Cox proportional hazards model was used to estimate multivariable hazard ratios (HRs) and 95% confidence intervals (95% CIs) for incident dementia.

RESULTS

During 58,013 person-years of follow-up, 946 persons developed dementia. In the primary analysis, compare to the lowest quintile of total dairy intake, Q2 showed a slightly decreased incident dementia risk (HR for Q2 vs Q1: 0.90, 95% CI: 0.73-1.10) after fully adjusted for demographic, lifestyle, psychological, and nutritional factors, and diseases history. Compared to non-consumers of milk, those consuming for 1-2 times/month showed a lower risk of incident dementia (fully-adjusted HR: 0.76, 95% CI: 0.57-1.02). Daily yogurt consumers also had a reduced risk (fully-adjusted HR: 0.89, 95% CI: 0.74-1.09). But daily cheese consumers showed an increased risk of dementia (fully-adjusted HR: 1.28, 95% CI: 0.91-1.79). In the sensitivity analysis where we excluded dementia cases ascertained in the first 2 years, results were consistent with those from the primary analysis and we further found that yogurt intake might be inversely associated with dementia risk (p for trend = 0.025).

CONCLUSION

Low total dairy intake or low milk intake frequency might be associated with lower incident dementia risk, however daily cheese consumers seemed to have an increased risk. Our study also suggested a possible inverse dose-response association between yogurt consumption and dementia risk, but further studies are needed to confirm whether this benefit was from yogurt intake itself or as a part of a healthy dietary pattern.

Interactive Effects of Obesity and Hypertension on Patterns of Hair Essential Trace Element and Mineral Content in Adult Women

The objective of the present study was to evaluate potential similar patterns and interactive effects of obesity and hypertension on hair essential trace element and mineral content in adult women. In this cross-sectional study, a total of 607 adult women divided into controls (n = 101), groups with obesity without hypertension (n = 199), hypertension without obesity (n = 143), and both obesity and hypertension (n = 164) were included in the study. Assessment of hair mineral and trace element levels was performed by inductively-coupled plasma mass-spectrometry. Hair Ca, Mg, Co, and Mn levels in women with obesity, hypertension, and both diseases were significantly lower, compared to controls. Hair Mg levels in women with obesity and hypertension were significantly lower, whereas hair Na and K were found to be higher when compared to other groups. Hair Fe and V content in obese patients was lower than in other groups. Obesity was associated with lower hair Cu levels, whereas patients with hypertension had higher hair Cu content. Hypertension was also associated with higher hair Cr and Se content irrespective of body weight. Hair Zn levels in obese women with and without hypertension were significantly lower than those in healthy controls and normal-weight women with hypertension. In multiple regression models hair Mg was considered as a significant negative predictor of both systolic and diastolic blood pressure values. The observed alterations in hair trace element and mineral content provide an additional link between obesity and hypertension, although further detailed studies are required.

A Retrospective Cohort Study of the Association Between Calcium Serum Level and Hypertension in Older Adults

INTRODUCTION

 One of the major global risk factors for cardiovascular morbidity and death is hypertension. Earlier research has been conducted on the connection between calcium consumption and blood pressure.

OBJECTIVE

This study aims to investigate the association between calcium serum levels and hypertension in older hypertensive adults.

METHODS

 A retrospective cohort study of 121 of hypertension patients was conducted in Prince Faisal Bin Khalid Cardiac Center. The data of all patients were collected by records, including lab, pathology, and medical review, in order to determine the effects on patients, providers, and institutions. Statistical analyses were performed using SPSS Statistics version 26.0. A p-value of <0.05 was considered statistically significant.

RESULTS

 The study included 121 adult hypertensive patients with a mean of age 60.29 ± 13.92. The majority of included patients were male (81%). More than one-third of patients were obese (39.7%), about one-third (33.9%) were overweight, and 26.4% of patients were in normal weight. The majority of patients had co-morbidities (68.3%); about one-half of them had diabetes mellitus (52.1%). The calcium level mean was 5.07 ± 1.26. The creatine kinase (CK) (initial day) mean ± SD was 813.22 ± 1146.37 became 221.4 ± 330.67 on the last day. The CK-myocardial band (CK-MB) (initial day) was 65.43 ± 118.9 and became 24.38 ± 23.26 on the last day. Additionally, the troponin (initial day) mean was 23.49 ± 104.26 and became 1.65 ± 2.66 on the last day. The most common discharge medications were anti-platelets (95%), beta-blockers (78.5%), statins (70.2%), and proton-pump inhibitors (PPI) (64.5%). The hospital stay days ranged from 1 to 20 days with a mean of 4.83 ± 3.38. The ICU stay days ranged from 1 to 15 days with a mean of 3.57 ± 2.72. Most of the patients (90.9%) improved.

CONCLUSION

There is no significant correlation between calcium levels in hypertensive patients and the demographic characteristics of patients, home or current medications, ECHO findings, or procedures done. However, there is a significant correlation between the calcium level and CK level among patients with hypertension. Further investigations are required to verify the relationship between CK and calcium levels in hypertensive patients.

Combined exposure to multiple dioxins and dioxin-like polychlorinated biphenyls on hypertension among US adults in NHANES: a cross-sectional study under three statistical models

Dioxins and dioxin-like polychlorinated biphenyls (DL-PCBs) are mainly released as by-products of human activities, often in the form of mixtures, and the potential harm on human health deserves attention. Therefore, our study aimed to analyze the combined effect of dioxins and DL-PCB exposures on hypertension (HTN) among US adults. Data of eligible participants were acquired from the National Health and Nutrition Examination Survey (NHANES). Multiple logistic regression models with adjustment for covariates were applied to explore the associations between 13 persistent organic pollutants (POPs) and HTN. Stratified analyses and interaction analyses were then conducted by age and gender. Finally, the combined effects of dioxins and DL-PCBs on HTN were assessed by the weighted quantile sum (WQS) model and the Bayesian kernel machine regression (BKMR) model. A total of 976 adults were included in our study, of whom 397 had HTN. Spearman correlations indicated positive correlations among 13 POPs. And most of them (except PCB28, PCB66, and 1,2,3,4,7,8,9-hpcdf) had significant effects on HTN. The result of WQS revealed that mixed exposure to dioxins and DL-PCBs was significantly associated with increased risk of HTN (OR: 2.205; 95% CIs: 1.555, 3.127). The BKMR model also presented a positive trend of HTN risk with exposure to multiple dioxins and DL-PCBs. And 1,2,3,4,6,7,8,9-ocdd may be the main factor for this positive association. Considering the limitations of our cross-sectional study with the small sample, further prospective studies are necessary to validate our findings.

Dietary oxalate-calcium balance and the incidence of hypertension and chronic kidney disease: a prospective study among an Asian population

Background

The potential effects of dietary oxalate (Ox) intake on cardio-renal function have remained unestablished. We evaluated the effect of usual Ox intake and its interaction with dietary calcium (Ca) on incident hypertension (HTN) and chronic kidney disease (CKD).

Methods

Adult men and women, free of HTN and CKD at baseline (2006–2008), were recruited. Dietary intakes were assessed using a validated food frequency questionnaire, and the outcomes were documented up to 2014–2017. Multivariate Cox proportional hazard regression models were used to estimate the development of HTN and CKD in relation to Ox intakes. Repeated-measures generalized estimating equation (GEE) linear regression models were used to assess possible effect of Ox-intake on the estimated glomerular filtration rate (eGFR) and blood pressure levels over eight years.

Results

Dietary Ox intakes were positively associated with incident CKD (HR = 2.59, 95% CI = 1.46–4.64) and HTN (HR = 1.79, 95% CI = 1.05–3.04). Compared to high-Ca consumers, subjects who had lower Ca intakes (< 990 vs. 1580 mg/d) had a higher incidence of CKD and HTN (HR = 2.43, 95% CI = 1.06–5.55, and HR = 1.72, 95% CI = 0.76–3.78). Participants with higher intakes of Ox (> 220 vs. < 150 mg/d) had lower eGFR values (75.3, 95% CI = 75.0–76.5 vs. 77.3, 95% CI = 76.6–78.1 mL/min/1.73m², P_time×group = 0.004) and higher SBP levels (112, 95% CI = 111–113 vs. 109, 95% CI = 108–110 mmHg, P_time×group = 0.007) overtime.

Conclusion

Higher dietary Ox intake may increase the risk of HTN and CKD. The relation between dietary Ox and risk of HTN and CKD seems to be varied by Ca intake, and subjects with lower Ca intakes may be more burdened by excessive amounts of dietary Ox.

Association of milk consumption with management and incidence of hypertension among South Korean adults: A prospective analysis of the health examinees study cohort

BACKGROUND AND AIMS

Studies have revealed a positive relationship between milk consumption and hypertension. However, few researchers have investigated the association between milk consumption and changes in blood pressure (BP) in South Korean adults. Therefore, we examined the association between milk intake and the management and risk of hypertension in South Korean adults.

METHODS AND RESULTS

Participants were selected from the Health Examinees study. The definition of hypertension was based on the guidelines of the Korean Society of Hypertension. The participants were divided into three groups according to changes between baseline and follow-up BP data. Milk consumption was assessed using food frequency questionnaires. In both men and women, the higher milk consumption group had increased odds of trends of BP improvement (OR: 1.249, 95% CI: 1.043-1.496, p for trend: 0.2271 in men; OR: 1.147, 95% CI: 1.014-1.297, p for trend: 0.0293 in women) and decreased odds of trends of worsening (OR: 0.861, 95% CI: 0.756-0.980, p for trend: <0.0001 in men, OR: 0.866, 95% CI: 0.794-0.943, p for trend: 0.0010 in women) compared to those of the non-consumption group. In the prospective study, milk intake was inversely associated with hypertension risk (HR: 0.900, 95% CI: 0.811-0.999, p for trend: 0.0076 in men; HR: 0.879, 95% CI: 0.814-0.949, p for trend: 0.0002 in women).

CONCLUSION

Increased intake of milk was inversely related to the risk of increased BP, with a decreased risk of hypertension events.

Vegan nutrition: a preliminary guide for health professionals

Since the beginning of the 21st century, interest in vegan diets has been rapidly increasing in most countries. Misconceptions about vegan diets are widespread among the general population and health professionals. Vegan diets can be health-promoting and may offer certain important advantages compared to typical Western (and other mainstream) eating patterns. However, adequate dietary sources/supplements of nutrients of focus specific to vegan diets should be identified and communicated. Without supplements/fortified foods, severe vitamin B12 deficiency may occur. Other potential nutrients of focus are calcium, vitamin D, iodine, omega-3 fatty acids, iron, zinc, selenium, vitamin A, and protein. Ensuring adequate nutrient status is particularly important during pregnancy, lactation, infancy, and childhood. Health professionals are often expected to be able to provide advice on the topic of vegan nutrition, but a precise and practical vegan nutrition guide for health professionals is lacking. Consequently, it is important and urgent to provide such a set of dietary recommendations. It is the aim of this article to provide vegan nutrition guidelines, based on current evidence, which can easily be communicated to vegan patients/clients, with the goal of ensuring adequate nutrient status in vegans.

U-shaped association between dietary calcium density intake during adolescence and hypertension in adulthood: a 20-year longitudinal nationwide study in China

We assessed longitudinal association between calcium intake during adolescence and hypertension in adulthood. Longitudinal study data of 1611 participants from the China Health and Nutrition Survey during 1991-2011 were used. On average they were followed for 11·4 years. Dietary calcium intake during adolescence was assessed based on three 24-hour dietary recalls collected in each visit/survey between 1991 and 2009 (seven waves). The intake was recoded into quartiles. Cumulative mean±SD calcium intake was 199·9±144·8 mg/1000 kcal/day during adolescence. In total 102 participants had hypertension in adulthood (97 men and 5 women). There was a clear U-shaped association between adolescence calcium intake quartiles and adulthood hypertension: across the quartiles, hypertension prevalence was 6·7%, 4·0%, 5·2% and 9·5%, respectively. After adjustment for potential confounders including weight status and dietary pattern, odds ratios (OR, 95% CI) for hypertension were 2·32 (95% CI 1·07-5·00) for lowest quartile, 1·00 (reference), 1·34 (95% CI 0·61-2·97), and 3·10 (95% CI 1·49-6·46) across the quartiles. Lower or higher calcium intake during adolescence was associated with hypertension in adulthood independent of weight status and dietary pattern.

Strategy for sodium-salt substitution: On the relationship between hypertension and dietary intake of cations

Chronic diseases, especially cardiovascular diseases (CVD), have become one of the main causes affecting human health. Hypertension is a prominent representative of CVD. The formation and development of hypertension is closely related to people's daily diet. A large number of studies have shown that excessive intake of salt (NaCl) could increase the risk of hypertension. In recent years, more and more investigations have focused on other cations that may be contained in edible salt, exploring whether they have an effect on hypertension and the underlying mechanism. This article focuses on the relationship between four metal elements (potassium, calcium, magnesium, and zinc) and hypertension, by discussing the main metabolic pathway, the impact of diet intake on blood pressure, and especially the regulation mechanisms on blood pressure in detail. At the same time, some opinions and suggestions are put forward, combined with the current hot topics "salt reduction" and "salt substitution".

An Empirical Evaluation of the Impact Scenario of Pooling Bodies of Evidence from Randomized Controlled Trials and Cohort Studies in Nutrition Research

Only very few Cochrane nutrition reviews include cohort studies (CSs), but most evidence in nutrition research comes from CSs. We aimed to pool bodies of evidence (BoE) from randomized controlled trials (RCTs) derived from Cochrane reviews with matched BoE from CSs. The Cochrane Database of Systematic Reviews and MEDLINE were searched for systematic reviews (SRs) of RCTs and SRs of CSs. BoE from RCTs were pooled together with BoE from CSs using random-effects and common-effect models. Heterogeneity, 95% prediction intervals, contributed weight of BoE from RCTs to the pooled estimate, and whether integration of BoE from CSs modified the conclusion from BoE of RCTs were evaluated. Overall, 80 diet-disease outcome pairs based on 773 RCTs and 720 CSs were pooled. By pooling BoE from RCTs and CSs with a random-effects model, for 45 (56%) out of 80 diet-disease associations the 95% CI excluded no effect and showed mainly a reduced risk/inverse association. By pooling BoE from RCTs and CSs, median I2 = 46% and the median contributed weight of RCTs to the pooled estimates was 34%. The direction of effect between BoE from RCTs and pooled effect estimates was rarely opposite (n = 17; 21%). The integration of BoE from CSs modified the result (by examining the 95% CI) from BoE of RCTs in 35 (44%) of the 80 diet-disease associations. Our pooling scenario showed that the integration of BoE from CSs modified the conclusion from BoE of RCTs in nearly 50% of the associations, although the direction of effect was mainly concordant between BoE of RCTs and pooled estimates. Our findings provide insights for the potential impact of pooling both BoE in Cochrane nutrition reviews. CSs should be considered for inclusion in future Cochrane nutrition reviews, and we recommend analyzing RCTs and CSs in separate meta-analyses, or, if combined together, with a subgroup analysis.

Association of Dietary Calcium Intake With Bone Health and Chronic Diseases: Two Prospective Cohort Studies in China

Background: Calcium is an essential element in our diet and the most abundant mineral in the body. A high proportion of Chinese residents are not meeting dietary calcium recommendations. The purpose of this study was to investigate the relationship between calcium intake and the health of residents in two longitudinal studies of Chinese residents.

Methods: This study used nationally representative data from the Harbin Cohort Study on Diet, Nutrition, and Chronic Non-communicable Disease Study (HDNNCDS) and China Health Nutrition Survey (CHNS), including 6,499 and 8,140 Chinese adults, respectively, who were free of chronic diseases at recruitment, with mean values of 4.2- and 5.3-year follow-up. Cox's proportional-hazards regression was conducted to explore the relationship between dietary calcium intake and the incidence of obesity, type 2 diabetes, hypertension, and cardiovascular disease (CVD) with adjustment for covariates.

Results: Calcium intakes were 451.35 ± 203.56 and 484.32 ± 198.61 (mean ± SD) mg/day in HDNNCDS and CHNS. After adjusting the covariates, the relationship between dietary calcium intake and bone mineral density (BMD) was not statistically significant (p = 0.110). In the multivariate-adjusted Cox's proportional-hazards regression model, dietary calcium intakes were inversely associated with obesity incidence in both cohorts (HR [95% CI]: 0.61 [0.48–0.77] and p trend < 0.001 in fixed-effects model); nevertheless, there was no correlation between dietary calcium intake and the risk of type 2 diabetes (p trend = 0.442 and 0.759) and CVD (p trend = 0.826 and 0.072). The relationship between dietary calcium intake and the risk of hypertension in the two cohorts was inconsistent (p trend = 0.012 and 0.559). Additionally, after further adjusting the vegetable intake in the original multivariate model, both cohorts found no association between dietary calcium intake and the risk of developing obesity (p trend = 0.084 and 0.444).

Conclusions: Our data suggest that the current calcium intake of Chinese residents was inversely associated with obesity, which may be related to consumption of vegetables. Meanwhile, the current calcium intake does not increase the risk of type 2 diabetes, CVD, and bone health burden. This research suggested that the Chinese current calcium intake level may have met the needs of the body.

Association between Milk Intake and Incident Stroke among Japanese Community Dwellers: The Iwate-KENCO Study

We aimed to evaluate the association between the milk consumption and incident stroke in a Japanese population, where milk consumption is lower than that of Western countries. In total, 14,121 participants (4253 men and 9868 women) aged 40–69 years, free from cardiovascular diseases (CVD) were prospectively followed for 10.7 years. Participants were categorized into four groups according to the milk intake frequency obtained from a brief-type self-administered diet questionnaire. The adjusted HRs of total stroke, ischemic stroke and haemorrhagic stroke associated with milk intake frequency were calculated using the Cox proportional hazards model. During the follow-up, 478 stroke cases were detected (208 men and 270 women). Compared to women with a milk intake of <2 cups/week, those with an intake of 7 to <12 cups/week had a significantly low risk of ischemic stroke in a model adjusting CVD risk factors; the HR (95% CI) was 0.53 (0.32–0.88). No significant associations were found in men. This study suggested that milk intake of 7 to <12 cups/week decreased the risk of ischemic stroke in Japanese women. Milk intake of about 1 to <2 cups/day may be effective in the primary prevention of ischemic stroke in a population with low milk intake.

Evaluating agreement between bodies of evidence from randomised controlled trials and cohort studies in nutrition research: meta-epidemiological study

OBJECTIVE

To evaluate the agreement between diet-disease effect estimates of bodies of evidence from randomised controlled trials and those from cohort studies in nutrition research, and to investigate potential factors for disagreement.

DESIGN

Meta-epidemiological study.

DATA SOURCES

Cochrane Database of Systematic Reviews, and Medline.

REVIEW METHODS

Population, intervention or exposure, comparator, outcome (PI/ECO) elements from a body of evidence from cohort studies (BoE(CS)) were matched with corresponding elements of a body of evidence from randomised controlled trials (BoE(RCT)). Pooled ratio of risk ratios or difference of mean differences across all diet-disease outcome pairs were calculated. Subgroup analyses were conducted to explore factors for disagreement. Heterogeneity was assessed through I2 and τ2. Prediction intervals were calculated to assess the range of possible values for the difference in the results between evidence from randomised controlled trials and evidence from cohort studies in future comparisons.

RESULTS

97 diet-disease outcome pairs (that is, matched BoE(RCT) and BoE(CS)) were identified overall. For binary outcomes, the pooled ratio of risk ratios comparing estimates from BoE(RCT) with BoE(CS) was 1.09 (95% confidence interval 1.04 to 1.14; I2=68%; τ2=0.021; 95% prediction interval 0.81 to 1.46). The prediction interval indicated that the difference could be much more substantial, in either direction. We further explored heterogeneity and found that PI/ECO dissimilarities, especially for the comparisons of dietary supplements in randomised controlled trials and nutrient status in cohort studies, explained most of the differences. When the type of intake or exposure between both types of evidence was identical, the estimates were similar. For continuous outcomes, small differences were observed between randomised controlled trials and cohort studies.

CONCLUSION

On average, the difference in pooled results between estimates from BoE(RCT) and BoE(CS) was small. But wide prediction intervals and some substantial statistical heterogeneity in cohort studies indicate that important differences or potential bias in individual comparisons or studies cannot be excluded. Observed differences were mainly driven by dissimilarities in population, intervention or exposure, comparator, and outcome. These findings could help researchers further understand the integration of such evidence into prospective nutrition evidence syntheses and improve evidence based dietary guidelines.

Calcium Intake Is Inversely Related to Risk of Obesity among American Young Adults over a 30-Year Follow-Up

BACKGROUND

Calcium (Ca) is an essential nutrient that may play an important role in weight maintenance through its involvement in energy or lipid metabolism. However, little is known about the long-term associations of Ca intake with obesity risk.

OBJECTIVES

We aimed to prospectively examine the association between cumulative Ca intake and the incidence of obesity among American young adults over 30 y of follow-up.

METHODS

Participants were from the CARDIA (Coronary Artery Risk Development in Young Adults) study. A total of 4097 of 5115 black and white individuals aged 18-30 y at baseline in 1985-1986 were included in the current analysis. Dietary and supplemental Ca intake was assessed by the validated interview-based CARDIA diet history at baseline and exam years 7 and 20. Incident cases of obesity were identified when BMI was ≥30 kg/m2 for the first time since baseline. A survival analysis was performed using Cox proportional hazards regression models to estimate the HRs and corresponding 95% CIs for obesity incidence during follow-up.

RESULTS

During a 30-y follow-up (mean ± SD: 20 ± 10 y), 1675 participants developed obesity. Cumulative total Ca intake (dietary plus supplemental Ca) was inversely associated with incidence of obesity in multivariable-adjusted analysis [quintile (Q)5 (highest intake) compared with Q1 (lowest intake): HR: 0.68; 95% CI: 0.56, 0.82; P-trend < 0.01]. This inverse association persisted among Ca supplement users (Q5 compared with Q1: HR: 0.53; 95% CI: 0.40, 0.70; P-trend < 0.01), but was not seen among nonusers.

CONCLUSIONS

Following a cohort of Americans from young adulthood to midlife, an inverse association between calcium intake and obesity incidence was observed. Further studies are needed to confirm our findings.

Extra-skeletal effects of dietary calcium: Impact on the cardiovascular system, obesity, and cancer

Calcium is well known to be integral to bone and muscle health, with deleterious effects such as osteoporosis associated with inadequate calcium intake. Recent studies have also highlighted the significant effects of calcium in extra-musculoskeletal functioning, including the cardiovascular system, obesity, and cancer. Calcium impacts the cardiovascular system as an antagonist associated with a reduction in hypertension, increase vasodilation, and improvement in blood vessel function when obtained in the diet as an organic source, through food. However, the inorganic source of calcium, found in supplements, may be negatively associated with the cardiovascular system due to plaque deposits and atherogenesis when taken in excess. Some studies suggest that calcium intake may impact obesity by regulation of adipogenesis and reducing fat deposits with resulting weight loss. The pathogenesis of calcium for reducing obesity is thought to be related in part to its impact on gut microbiota profile, with the suggestion that calcium may have prebiotic properties. Animal and some human studies propose that calcium may also have a role in cancer prevention and/or treatment due to its function in the cell proliferation process and the impact on hormonal regulation, and thus warrants more investigations in the human population. Some prospective and small clinical studies suggest that calcium may be beneficial for colorectal cancer. Overall, emerging research in various areas continues to highlight the essentiality of dietary calcium for functioning at the molecular and biochemical level toward improvement in health and some chronic disease conditions.

Rural and Urban Population Differences in the Association of Dietary Calcium with Blood Pressure and Hypertension Occurrence: Analysis of Longitudinal Data from the China Health and Nutrition Survey

The relationship of dietary calcium intake (DCI) to blood pressure (BP) and hypertension occurrence (HTN) in the general population is controversial. Few studies have reported the impact of DCI on high blood pressure (HBP) and HTN in rural and urban populations (RPs and UPs, respectively). In this study, we assessed how DCI is related to BP and HTN among the RP and the UP. This retrospective study used data from the Chinese Health and Nutrition Survey (CHNS) for 2000–2009. We analyzed 12,052 records from 3013 participants using path analysis and logistic regressions. DCI and HTN were significantly higher in the UP compared to the RP. When UPs and RPs were analyzed together, a 1 unit increase in DCI decreased systolic blood pressure (SBP) by 0.01 (p = 0.002) but had no effect on diastolic blood pressure. Males vs. females from the RP presented significant risk of HTN by the high DCI (OR = 2.3 (1.6–3.6)). DCI and its association with BP varied based on living environment and sex.

Effect of Calcium and Vitamin D Co-supplementation on Blood Pressure: A Systematic Review and Meta-Analysis

PURPOSE

Vitamin D and calcium insufficiency has been related to elevated blood pressure (BP) and cardiovascular complications. This systematic review and meta-analysis investigates the effect of calcium and vitamin D co-supplementation on BP.

METHODS

A systematic search was conducted of electronic databases, including Web of Sciences, MEDLINE, Scopus, EMBASE, and the Cochrane Library, along with searches of gray literature and reference lists from included trials. There were no language restrictions, and the databases were searched from inception to October 2019. Randomized controlled trials, using calcium and vitamin D co-supplementation and reporting mean systolic BP and/or diastolic BP (DBP) with SDs, were included in the systematic review. Articles were evaluated independently by 2 researchers based on inclusion and exclusion criteria. A random effects model was conducted to synthesize the data.

FINDINGS

Eight trials were included in the meta-analysis. Meta-analysis of these 8 trials indicated a nonsignificant reduction in systolic BP in the calcium and vitamin D co-supplementation group compared with control (standardized mean difference, -0.23; 95% CI, -0.52 to 0.06). Conversely, there was a statistically significant decrease in DBP (standardized mean difference, -0.29; 95% CI, -0.55 to -0.02). Subgroup analysis suggested that young adults achieve a greater reduction in DBP than other age groups.

IMPLICATIONS

Calcium and vitamin D co-supplementation can modulate DBP and should be investigated more specifically in large, well-designed trials of hypertensive populations. (Clin Ther. 2020;42:XXX-XXX) © 2020 Elsevier HS Journals, Inc.

Dietary Calcium Intake and the Risk of Metabolic Syndrome: A Systematic Review and Meta-Analysis

Growing evidence has suggested a possible relationship between dietary calcium intake and metabolic syndrome (MetS) risk. However, the findings of these observational studies are inconclusive, and the dose-response association between calcium intake and risk of MetS remains to be determined. Here, we identified relevant studies by searching PubMed and Web of Science databases up to December 2018, and selected observational studies reporting relative risk (RR) with 95% confidence interval (CI) for MetS based on calcium intake and estimated the summary RRs using random-effects models. Eight cross-sectional and two prospective cohort studies totaling 63,017 participants with 14,906 MetS cases were identified. A significantly reduced risk of MetS was associated with the highest levels of dietary calcium intake (RR: 0.89; 95% CI: 0.80–0.99; I² = 75.3%), with stronger association and less heterogeneity among women (RR: 0.74, 95% CI: 0.66–0.83; I² = 0.0%) than among men (RR: 1.06, 95% CI: 0.82–1.37; I² = 72.6%). Our dose-response analysis revealed that for each 300 mg/day increase in calcium intake, the risk of MetS decreased by 7% (RR: 0.93; 95% CI: 0.87–0.99; I² = 77.7%). In conclusion, our findings suggest that dietary calcium intake may be inversely associated with the risk of MetS. These findings may have important public health implications with respect to preventing the disease. Further studies, in particular longitudinal cohort studies and randomized clinical trials, will be necessary to determine whether calcium supplementation is effective to prevent MetS.

Dietary Calcium Intake and Hypertension: Importance of Serum Concentrations of 25-Hydroxyvitamin D

The relationship among dietary calcium, hypertension and vitamin D status currently remains unclear. This population-based cross-sectional study examined the association between dietary calcium intake and hypertension and the influence of serum concentrations of 25-hydroxyvitamin D [25(OH)D] in Japanese subjects. A total of 619 subjects aged from 40 years were recruited. Dietary intake was measured using a validated brief self-administered diet history questionnaire. Hypertension was defined as the use of antihypertensive medication or a blood pressure of 140/90 mmHg. Serum concentrations of 25(OH)D were used as the biomarker of vitamin D status. The prevalence of hypertension and low serum 25(OH)D levels (<20 ng/mL) were 55 and 32%, respectively. Dietary calcium intake inversely correlated with hypertension in subjects with serum 25(OH)D levels higher than 20 ng/mL (OR: 0.995; 95% CI: 0.991, 0.999) but it was not significant in those with serum 25(OH)D levels of 20 ng/mL or lower. Furthermore, dietary vitamin D intake correlated with serum concentrations of 25(OH)D after adjustments for various confounding factors. The present results demonstrate that the regular consumption of calcium may contribute to the prevention and treatment of hypertension in subjects with a non-vitamin D deficiency and also that dietary vitamin D intake may effectively prevents this deficiency.

Lactose Intolerance, Dairy Avoidance, and Treatment Options

Lactose intolerance refers to symptoms related to the consumption of lactose-containing dairy foods, which are the most common source for this disaccharide. While four causes are described, the most common is the genetically-determined adult onset lactose maldigestion due to loss of intestinal lactase governed by control of the gene by a 14,000 kb promoter region on chromosome 2. Gastrointestinal symptoms from lactose have expanded to include systemic effects and have also been confounded by other food intolerances or functional gastrointestinal disorders. Partly because lactose maldigestion is often interpreted as lactose intolerance (symptoms), focus of therapy for these symptoms starts with lactose restriction. However, withholding of dairy foods completely is not appropriate due to a more favorable impact on health. Industrial efforts to substitute with plant-based products is not completely successful at this time. This narrative article reviews the complexities of the perception of lactose intolerance, its epidemiology, and pathogenesis. Treatments are discussed, including the inappropriateness of dairy avoidance. In conjunction, effects of dairy products on 19 common diseases are reviewed. Different methods of treatment, lactose-reduced products, plant-based dairy substitutes, adaptation, prebiotics, exogenous lactase, probiotics, and some other dietary interventions are further discussed.