The influence of calcium and magnesium in drinking water and diet on cardiovascular risk factors in individuals living in hard and soft water areas with differences in cardiovascular mortality

The Relationship between Mortality from Cardiovascular Diseases and Total Drinking Water Hardness: Systematic Review with Meta-Analysis

BACKGROUND

Interest in water chemical activity, its content, and its impact on human health has greatly increased throughout the last decade. Some studies suggest that drinking water with high hardness may have preventative effects on cardiovascular diseases. This study aims to investigate the association between drinking water hardness and cardiovascular disease (CVD) mortality.

METHODS

The study selection process was designed to find the association between drinking water hardness and CVDs mortality. The search included both qualitative and quantitative research and was performed in three databases: Web of Science (Clarivate Analytics, Ann Arbor, MI, USA), PubMed (National Institute of Health, Bethesda, MA, USA), and Scopus (Elsevier, RELX Group plc, London, UK). The project was registered in the International Prospective Register of Systematic Reviews (PROSPERO), registration number: CRD42020213102.

RESULTS

Seventeen studies out of a total of twenty-five studies qualitatively analyzed indicated a significant relation between total water hardness and protection from CVD mortality. The quantitative analysis concluded that high drinking water hardness has a significantly lowering effect on mortality from CVDs, however, the heterogeneity was high.

CONCLUSIONS

This systematic literature review shows that total water hardness could affect CVD prevention and mortality. Due to the many confounding factors in the studies, more research is needed.

Exploring the Potential Benefits of Natural Calcium-Rich Mineral Waters for Health and Wellness: A Systematic Review

This systematic review investigates the potential health and wellness benefits of natural calcium-rich mineral waters. It emphasizes the importance of dietary calcium sourced from natural mineral waters in promoting bone health, maintaining cardiovascular function, aiding in weight management, and enhancing overall well-being. The review process involved the comprehensive analysis of peer-reviewed articles, clinical trials, and experimental studies published within the last decade. Findings reveal that consuming calcium-rich mineral water can contribute significantly to daily calcium intake, particularly for those with lactose intolerance or individuals adhering to plant-based diets. The unique bioavailability of calcium from such waters also appears to enhance absorption, thus potentially offering an advantage over other calcium sources. The potential benefits extend to the cardiovascular system, with some studies indicating a reduction in blood pressure and the prevalence of cardiovascular diseases. Emerging evidence suggests that calcium-rich mineral water might have a role in body weight management, though further research is needed. The review identifies several areas requiring additional research, such as the potential interaction between calcium-rich mineral water and other dietary components, the effects on populations with specific health conditions, and the long-term effects of consumption. In conclusion, natural calcium-rich mineral waters show promise as a readily accessible and bioavailable sources of dietary calcium, potentially beneficial for a broad range of individuals. However, further investigation is required to fully understand its range of health impacts and define optimal intake levels.

Dynamics of land cover changes and condition of soil and surface water quality in a Mining-Altered landscape, Ghana

This study investigated the dynamics of mining effects on land use land cover changes and the chemical and physical characteristics of soil and surface water in the Ahafo mining area in Ghana. Landsat imagery was used to analyze land use-land cover changes (LULC) using a supervised classification technique. Soil samples were collected within 600 m from active mining operations and at depths of up to 75 cm, as well as surface water samples from upstream and downstream of the mine. Atomic Absorption Spectrometry was used to determine the concentration of heavy metals in the soil and water samples. The results demonstrated a significant loss of forest and other vegetation covers, which decreased from 44% to 31% to 8% and 20%, respectively, with corresponding increases in the mining site, mine water, settlement/bare surface, cropland and plantation. Organic matter, organic carbon, exchangeable bases, cation exchange capacity, available phosphorus, and pH were all moderate in the soil surrounding the mine. Except for As (4.027 mg/kg) and Hg (1 mg/kg), all heavy metals found in the soil were within FAO/WHO guidelines. Total Dissolved Solids (TDS) (416.18 mg/L), Total Suspended Solids (55.08 mg/L), Turbidity (54.49 NTU), Ca (84.49 mg/L), Mg (31.97 mg/L), nitrate (10.23 mg/L), and sulphate (606.83 mg/L) in the downstream water were higher than those in the upstream and USEPA/WHO limits for drinking water except for TDS. Because of the geology of the area, there were high concentrations of iron, manganese, and aluminum in the surface water. The results show that mining induced severe land cover changes and impaired surface water and soil quality in the mine's vicinity. The findings have implications for stakeholder education, appropriate community water interventions, and company-community-regulator participatory monitoring to avoid health risk exposure and further water and soil quality and vegetation degradation.

Investigation of Calcium and Magnesium Removal by Donnan Dialysis According to the Doehlert Design for Softening Different Water Types

In this study, calcium and magnesium were removed from Tunisian dam, lake, and tap water using Donnan Dialysis (DD) according to the Doehlert design. Three cation-exchange membranes (CMV, CMX, and CMS) were used in a preliminary investigation to establish the upper and lower bounds of each parameter and to more precisely pinpoint the optimal value. The concentration of compensating sodium ions [Na⁺] in the receiver compartment, the concentration of calcium [Ca²⁺] and magnesium [Mg²⁺] in the feed compartment, and the membrane nature were the experimental parameters. The findings indicate that the CMV membrane offers the highest elimination rate of calcium and magnesium. The Full Factorial Design makes it possible to determine how the experimental factors affect the removal of calcium and magnesium by DD. All parameters used had a favorable impact on the response; however, the calcium and magnesium concentration were the most significant ones. The Doehlert design's Response Surface Methodology (RSM) was used to determine the optimum conditions ([Mg²⁺] = 90 mg·L^-1, [Ca²⁺] = 88 mg·L^-1, [Na⁺] = 0.68 mol·L^-1) allowing a 90.6% hardness removal rate with the CMV membrane. Finally, we used Donnan Dialysis to remove calcium and magnesium from the three different types of natural water: Dam, Lake, and Tap water. The results indicate that, when compared to lake water and tap water, the removal of calcium and magnesium from dam water is the best. This can be linked to the water matrix's complexity. Therefore, using Donnan Dialysis to decrease natural waters hardness was revealed to be suitable.

Associations of alkaline water with metabolic risks, sleep quality, muscle strength: A cross-sectional study among postmenopausal women

Much has been claimed on the health benefits of alkaline water including metabolic syndrome (MetS) and its features with scarcity of scientific evidence. Methods: This cross-sectional comparative study was conducted to determine whether regular consumption of alkaline water confers health advantage on blood metabolites, anthropometric measures, sleep quality and muscle strength among postmenopausal women. A total of 304 community-dwelling postmenopausal women were recruited with comparable proportion of regular drinkers of alkaline water and non-drinkers. Participants were ascertained on dietary intake, lifestyle factors, anthropometric and biochemical measurements. Diagnosis of MetS was made according to Joint Interim Statement definition. A total of 47.7% of the participants met MS criteria, with a significant lower proportion of MetS among the alkaline water drinkers. The observed lower fasting plasma glucose (F(1,294) = 24.20, p = 0.025, partial η2 = 0.435), triglyceride/high-density lipoprotein concentration ratio (F(1,294) = 21.06, p = 0.023, partial η2 = 0.360), diastolic blood pressure (F(1,294) = 7.85, p = 0.046, partial η2 = 0.258) and waist circumference (F(1,294) = 9.261, p = 0.038, partial η2 = 0.263) in the alkaline water drinkers could be considered as favourable outcomes of regular consumption of alkaline water. In addition, water alkalization improved duration of sleep (F(1,294) = 32.05, p = 0.007, partial η2 = 0.451) and handgrip strength F(1,294) = 27.51, p = 0.011, partial η2 = 0.448). Low density lipoprotein cholesterol concentration (F(1,294) = 1.772, p = 0.287, partial η2 = 0.014), body weight (F(1,294) = 1.985, p = 0.145, partial η2 = 0.013) and systolic blood pressure (F(1,294) = 1.656, p = 0.301, partial η2 = 0.010) were comparable between the two different water drinking behaviours. In conclusion, drinking adequate of water is paramount for public health with access to good quality drinking water remains a critical issue. While consumption of alkaline water may be considered as a source of easy-to implement lifestyle to modulate metabolic features, sleep duration and muscle strength, further studies are warranted for unravelling the precise mechanism of alkaline water consumption on the improvement and prevention of MetS and its individual features, muscle strength and sleep duration as well as identification of full spectrum of individuals that could benefit from its consumption.

Hydrochemical characterization of groundwater quality using chemometric analysis and water quality indices in the foothills of Himalayas

Groundwater pollution of the watershed is mainly influenced by the multifaceted interactions of natural and anthropogenic process. To analyse the spatial-temporal variation and pollution source identification and apportionment, the dataset was subjected to a globally acknowledged coherent technique using water quality indices and chemometric techniques (principal component analysis (PCA) and cluster analysis. The bulk of the samples tested were below the BIS's permissible levels. Groundwater samples from the pre- and post-monsoon seasons mostly contained the anions HCO- 3 > Cl- > SO2- 4 > NO- 3, while the primary cations were Ca2+ > Mg2+ > Na+ > K+. Groundwater was alkaline and hard at most of the sites. According to hydro-geochemical facies and relationships, Piper diagrams, and principal component analysis, weathering, dissolution, leaching, ion exchange, and evaporation were the key mechanisms influencing groundwater quality. The hydrochemical facies classified the groundwater samples into the Ca-Mg-HCO3 type. For all the sampling locations, PIG was determined to be 0.43, 0.52, 0.47, 0.48, 1.00, and 0.70; respectively. The majority of the test locations fell into the low to medium contamination zone, as determined by the groundwater pollution index (PIG) and contamination index. Three principal components, which together account for 93.8% of the total variance, were identified via PCA. The study's findings confirm the value of these statistical techniques in interpreting and understanding large datasets and offering reliable information to reduce the time and expense of programmes for monitoring and evaluating water quality.

A Paper-Based Potentiometric Platform for Determination of Water Hardness

A novel paper-based potentiometric platform for the simple and fast monitoring of water hardness is presented. First, potentiometric ion-selective electrodes for calcium and magnesium printed on a paper substrate were built and optimized. These sensors, which display near-Nernstian sensitivity, were used for the determination of the concentration of these cations and the calculation of the water hardness. Second, the incorporation of a solid-state reference electrode allowed building an integrated paper-based potentiometric cell for the determination of the hardness of artificial and real samples (mineral waters). The validation of the results shows good ability to predict hardness in the conventional scale. Truly decentralized measurements were demonstrated by integration of a miniaturized instrument and dedicated software in a portable device. The measurements were able to be performed in just under two minutes, including a two-point calibration. Since the method is simple to use and cost-effective, it can be implemented in domestic and industrial settings.

Crosstalk of Magnesium and Serum Lipids in Dyslipidemia and Associated Disorders: A Systematic Review

Dyslipidemia is a significant threat to public health worldwide and the identification of its pathogenic mechanisms, as well as novel lipid-lowering agents, are warranted. Magnesium (Mg) is a key element to human health and its deficiency has been linked to the development of lipid abnormalities and related disorders, such as the metabolic syndrome, type 2 diabetes mellitus, or cardiovascular disease. In this review, we explored the associations of Mg (dietary intake, Mg concentrations in the body) and the lipid profile, as well as the impact of Mg supplementation on serum lipids. A systematic search was computed in PubMed/MEDLINE and the Cochrane Library and 3649 potentially relevant papers were detected and screened (n = 3364 following the removal of duplicates). After the removal of irrelevant manuscripts based on the screening of their titles and abstracts (n = 3037), we examined the full-texts of 327 original papers. Finally, after we applied the exclusion and inclusion criteria, a number of 124 original articles were included in this review. Overall, the data analyzed in this review point out an association of Mg concentrations in the body with serum lipids in dyslipidemia and related disorders. However, further research is warranted to clarify whether a higher intake of Mg from the diet or via supplements can influence the lipid profile and exert lipid-lowering actions.

Water hardness zoning of Isfahan Province, Iran, and its relationship with cardiovascular mortality, 2013-2015

BACKGROUND

Cardiovascular disease (CVD) is one of the common diseases and today, it is considered as not only an important cause of mortality but also a significant aspect of health geography. The evidence presented in the literature indicates that hard water may reduce the cases of sudden death caused by CVDs because drinking water contains significant amounts of calcium and magnesium, which play a crucial role in the electrical activity of heart. Hence, the present study aimed at investigating the relationship between water hardness and CVD mortality rate in Isfahan, Iran.

METHODS

In this ecological study, the available data regarding the cardiovascular mortality rate and water hardness have been used. Preparation of zoning map has been conducted using the Geographic Information System (GIS) software considering Inverse Distance Weighting (IDW) interpolation models. Moreover, statistical analysis has been conducted using SPSS software.

RESULTS

A reverse relationship was observed between cardiovascular mortality rate and water hardness. However, the observed relationship was not statistically significant (2013: r = -0.066, 2014: r = -0.155, 2015: r = -0.051, P > 0.050).

CONCLUSION

The results of mapping with GIS and statistical analysis with SPSS both indicated a non-significant inverse relationship between the water hardness and CVDs. However, lack of a significant relationship highlights the necessity of conducting similar studies involving larger sample sizes and wider areas of investigation to present a definitive and generalizable result.

Mg-Based Micromotors with Motion Responsive to Dual Stimuli

Mg-based micromotors have emerged as an extremely attractive artificial micro/nanodevice, but suffered from uncontrollable propulsion and limited motion lifetime, restricting the fulfillment of complex tasks. Here, we have demonstrated Mg-based micromotors composed of Mg microspheres asymmetrically coated with Pt and temperature-sensitive poly(N-isopropylacrylamide) (PNIPAM) hydrogel layers in sequence. They can implement different motion behaviors stemming from the driving mechanism transformation when encountering catalyzed substrates such as H₂O₂ and respond to both H₂O₂ concentration and temperature in aqueous environment. The as-constructed Mg-based micromotors are self-propelled by Pt-catalyzed H₂O₂ decomposition following the self-consuming Mg-H₂O reaction. In this case, they could further generate bilateral bubbles and thus demonstrate unique self-limitation motion like hovering when the phase transformation of PNIPAM is triggered by decreasing temperature or when the H₂O₂ concentration after permeating across the PNIPAM hydrogel layer is high enough to facilitate bubble nucleation. Our work for the first time provides a stimuli-induced "hovering" strategy for self-propelled micromotors, which endows Mg-based micromotors with an intelligent response to the surroundings besides the significant extension of their motion lifetime.

Drinking water quality in areas impacted by oil activities in Ecuador: Associated health risks and social perception of human exposure

The unregulated oil exploitation in the Northern Ecuadorian Amazon Region (NEAR), mainly from 1964 to the 90's, led to toxic compounds largely released into the environment. A large majority of people living in the Amazon region have no access to drinking water distribution systems and collects water from rain, wells or small streams. The concentrations of major ions, trace elements, PAHs (polycyclic aromatic hydrocarbons) and BTEX (benzene, toluene, ethylbenzene, xylenes) were analyzed in different water sources to evaluate the impacts of oil extraction and refining. Samples were taken from the NEAR and around the main refinery of the country (Esmeraldas Oil Refinery/State Oil Company of Ecuador) and were compared with domestic waters from the Southern region, not affected by petroleum activities. In most of the samples, microbiological analysis revealed a high level of coliforms representing significant health risks. All measured chemical compounds in waters were in line with national and international guidelines, except for manganese, zinc and aluminum. In several deep-water wells, close to oil camps, toluene concentrations were higher than the natural background while PAHs concentrations never exceeded individually 2 ng·L^-1. Water ingestion represented 99% of the total exposure pathways for carcinogenic and non-carcinogenic elements (mainly zinc) in adults and children, while 20% to 49% of the Total Cancer Risk was caused by arsenic concentrations. The health index (HI) indicates acceptable chronic effects for domestic use according the US-EPA thresholds. Nevertheless, these limits do not consider the cocktail effects of metallic and organic compounds. Furthermore, they do not include the social determinants of human exposure, such as socio-economic living conditions or vulnerability. Most (72%) of interviewed families knew sanitary risks but a discrepancy was observed between knowledge and action: religious beliefs, cultural patterns, information sources, experience and emotions play an important role front to exposure.

Association of consumption of excess hard water, body mass index and waist circumference with risk of hypertension in individuals living in hard and soft water areas

Chronic exposure to soft drinking water increases the risk of hypertension. We conducted a cross-sectional study in 2017 in two study areas in the Poldasht County to assess the relation of hardness, body mass index and waist circumference with risk of hypertension. Total water hardness was measured by gravimetric methods. Hardness of > 180 ppm was considered to be hard drinking water. The Shiblu and Gharghologh areas had a four times higher mean total hardness level in drinking water (968.69 mg/L as CaCO₃) than the Sarisoo and Agh Otlogh (180 mg/L as CaCO₃) areas. According to the results of the study, the prehypertension prevalence in areas with high and low water hardness was calculated as 23.15% (18.11-29.15) and 46.84% (37.61-57.64), respectively. Moreover, the result showed the prevalence of hypertension and prehypertension was higher in regions with low hardness than those with high hardness, which was statistically significant (P < 0.001). The results of logistic regression showed that age, body mass index, waist circumference and hardness of drinking water were significantly related to hypertension. Accordingly, hypertension was low in people of regions with high hardness (OR 0.26, 0.17-0.42). This report examined whether total hardness in drinking water was protective against hypertension. This is an important finding for the ministry of human health as well as for the water and sewage company.

Colorimetric detection of magnesium (II) ions using tryptophan functionalized gold nanoparticles

The functional nanoparticles with specific molecular probe appear to be a promising approach for developing colorimetric nanosensor. In this work, we have synthesized tryptophan capped gold nanoparticles (AuNPs) and used to establish colorimetric detection of magnesium (Mg²⁺). The colorimetric response of the AuNPs toward Mg²⁺ was noticed with naked eyes, and spectral changes were monitored by using UV-Vis spectrophotometer. The detection response was rapid (less than 1 min), with a detection limit (LOD) about 0.2 µmol L⁻¹. The proposed nanoprobe shows characteristic red-shift of the AuNPs at 620 nm and high selectivity for Mg²⁺ due to the binding affinity of the tryptophan with Mg²⁺. The real-time response of the UV-Vis spectrum was monitored at three different concentrations of Mg²⁺ (0.45, 0.50, and 0.55 µmol L⁻¹). The AuNPs probe was suitable to provide a molecular platform for selective coordination with Mg²⁺ over Ca²⁺ ions, thus it could be facile to establish a practically viable sensing system. Furthermore, experimental results were confirmed to exhibit excellent linear curve for urine and serum samples spiked with Mg²⁺. Thus, this nanosensor is practically useful for the detection of Mg²⁺, without using expensive instruments, enzymes and/or DNA molecules.

Impact of Calcium and Magnesium in Groundwater and Drinking Water on the Health of Inhabitants of the Slovak Republic

This work aims to evaluate the impact of the chemical composition of groundwater/drinking water on the health of inhabitants of the Slovak Republic. Primary data consists of 20,339 chemical analyses of groundwater (34 chemical elements and compounds) and data on the health of the Slovak population expressed in the form of health indicators (HI). Fourteen HIs were evaluated including life expectancy, potential years of lost life, relative/standardized mortality for cardiovascular and oncological diseases, and diseases of the gastrointestinal and respiratory systems. The chemical and health data were expressed as the mean values for each of the 2883 Slovak municipalities. Artificial neural network (ANN) was the method used for environmental and health data analysis. The most significant relationship between HI and chemical composition of groundwater was documented as Ca + Mg (mmol·L⁻¹), Ca and Mg. The following limit values were set for these most significant groundwater chemical parameters: Ca + Mg 2.9–6.1 mmol·L⁻¹, Ca 78–155 mg·L⁻¹ and Mg 28–54 mg·L⁻¹. At these concentration ranges, the health of the Slovak population is the most favorable and the life expectancy is the highest. These limit values are about twice as high in comparison to the current Slovak valid guideline values for drinking water.

Cardiovascular diseases and hard drinking waters: implications from a systematic review with meta-analysis of case-control studies

This systematic review with meta-analysis, performed according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines, aims at evaluating the potential correlation between magnesium and calcium concentration in drinking waters and the risk of cardiovascular diseases (CVD), which impose a considerable burden in high-income countries. Included studies were of the case-control studies type. From an initial list of 643 potentially eligible articles, seven studies were finally retained in the quantitative analysis. Since each one of them assessed different ion concentrations, subjects exposed to the highest concentration versus those exposed to the lowest concentration were compared. By including an overall figure of 44,000 subjects, the result suggests a protective effect of the ions on CVD prevention, with an effect-size (ES) of 0.82 (95% confidence interval CI = [0.70-0.95], p-value = 0.008) for calcium, and ES = 0.75 (95% CI = [0.66-0.86], p-value = 0.000) for magnesium. Hard water consumption seems to be protective against CVD. However, the high heterogeneity (I² = 75.24, p-value = 0.001 for calcium; I² = 72.96, p-value = 0.0024 for magnesium) and the existence of publication bias limits the robustness and generalizability of these findings. Further high-quality studies are needed to reproduce and confirm these results.

Review of epidemiological studies on drinking water hardness and cardiovascular diseases

BACKGROUND

Major risk factors do not entirely explain the worldwide variability of morbidity and mortality due to cardiovascular disease. Environmental exposures, including drinking water minerals may affect cardiovascular disease risks.

METHOD

We conducted a qualitative review of the epidemiological studies of cardiovascular disease and drinking water hardness and calcium and magnesium levels.

RESULTS

Many but not all ecological studies found an inverse (i.e., protective) association between cardiovascular disease mortality and water hardness, calcium, or magnesium levels; but results are not consistent. Some case-control studies and one cohort study found either a reduced cardiovascular disease mortality risk with increased drinking water magnesium levels or an increased risk with low magnesium levels. However, the analytical studies provide little evidence that cardiovascular risks are associated with drinking water hardness or calcium levels.

CONCLUSION

Information from epidemiological and other studies supports the hypothesis that a low intake of magnesium may increase the risk of dying from, and possibly developing, cardiovascular disease or stroke. Thus, not removing magnesium from drinking water, or in certain situations increasing the magnesium intake from water, may be beneficial, especially for populations with an insufficient dietary intake of the mineral.

Natural fluoride in drinking water and myocardial infarction: A cohort study in Sweden

Large geographical variation in the coronary heart disease (CHD) incidence is seen worldwide and only a part of this difference is attributed to the classic risk factors. Several environmental factors, such as trace elements in the drinking water have been implicated in the pathogenesis of CHD. The objective was to assess the association between drinking water fluoride exposure and myocardial infarction in Sweden using nationwide registers. This large cohort consisted of 455,619 individuals, born in Sweden between January 1, 1900 and December 31, 1919, alive and living in their municipality of birth at the time of start of follow-up. Estimated individual drinking water fluoride exposure was stratified into four categories: very low (<0.3mg/l), low (0.3-<0.7mg/l), medium (0.7-<1.5mg/l) and high (≥1.5mg/l). In Cox regression analyses, compared to the very low fluoride group, the adjusted Hazard Ratio for the low fluoride group was 0.99 (95% confidence interval, 0.98-1.00), for the medium fluoride group 1.01 (95% confidence interval, 0.99-1.03) and 0.98 (95% confidence interval, 0.96-1.01) for the highest fluoride group. Adding water hardness to the model did not change the results. We conclude that the investigated levels of natural drinking water fluoride content does not appear to be associated with myocardial infarction, nor related to the geographic myocardial infarction risk variation in Sweden. Potential misclassification of exposure and unmeasured confounding may have influenced the results.

Knowledge, attitudes and practice of desalinated water among professionals in health and water departments in Shengsi, China: a qualitative study

Desalination has been considered as an essential way to solve water stress all over the world. Most of previous studies focused on its environmental impacts, energy consumption and desalination technologies rather than human health. However, the safety of desalinated water remains unclear. This study was undertaken to investigate the knowledge, attitude and practice (KAP) of the residents in an island county in eastern China to desalinated water. Seventeen people working in medical and water industries were recruited, and focus group discussion and in-depth interview were conducted among them. Our results showed that the majority of people interviewed knew the definition and local supply pattern of desalinated water, while some of them showed some concern about the safety and nutrition of desalinated water. Current drinking water standard has no specific item for desalination, so we strongly suggest issuing a standard for desalinated water.

Area epidemiological research on hypertension risk factors of Keriyans in the Taklimakan Desert

INTRODUCTION

The Keriyans live in the hot, arid areas of Taklimakan Desert and maintain a primitive way of life. They have a low incidence of hypertension. However, little is known about the adaptive compensation in the organism. In the present study, we explored the the traditional risk factors of hypertension in the Keriyans.

MATERIALS AND METHODS

We performed an epidemiological survey of Keriyans in a randomly selected natural population including 508 individuals aged 16 years or more, using the WHO MONICA scheme and 151 randomly selected age/gender-matched controls, Uighurs, from the nearest villagers to the Keriyans.

RESULTS

The incidence of hypertension in the Keriyans was significantly lower than that in the controls(p<0.001). Multivariate logistic regression analysis indicated that age, hyperglycemia and salt consumption as well as sodium intake in diet were associated with traditional hypertension risk factors. Correlation between water quality and hypertension showed that calcium was positively associated with the detection rate of hypertension.

CONCLUSIONS

Age, hyperglycemia and salt consumption as well as sodium intake in diet were correlated with hypertension risk factors, which leads to the speculation that the water of the desert draught area which is characterized by low calcium and high magnesium levels might account for the low incidence of hypertension in Keriyans.

First report on the association of drinking water hardness and endothelial function in children and adolescents

INTRODUCTION

This study aims to investigate the relationship of water hardness and its calcium and magnesium content with endothelial function in a population-based sample of healthy children and adolescents.

MATERIAL AND METHODS

This case-control study was conducted in 2012 among 90 individuals living in two areas with moderate and high water hardness in Isfahan County, Iran. The flow-mediated dilatation (FMD) of the brachial artery and the serum levels of soluble adhesion molecules (sICAM-1, sVCAM-1) were measured as surrogate markers of endothelial function, and high-sensitivity C-reactive protein (hs-CRP), as a marker of inflammation.

RESULTS

Data of 89 participants (51% boys, mean age 14.75 (2.9) years) were complete. Those participants living in the area with high water hardness had higher FMD, hs-CRP, and soluble adhesion molecules (sICAM-1, sVCAM-1) than their counterparts living in the area with moderate water hardness. Multiple linear regression analysis showed that after adjustment for confounding factors of age, gender, body mass index, healthy eating index and physical activity level, total water hardness, as well as water content of calcium and magnesium, had a significant positive relationship with FMD. The corresponding associations were inverse and significant with soluble adhesion molecules (p < 0.05).

CONCLUSIONS

This study, which to the best of our knowledge is the first of its kind in the pediatric age group, suggests that water hardness, as well as its calcium and magnesium content, may have a protective role against early stages of atherosclerosis in children and adolescents.

Effect of a high bicarbonate mineral water on fasting and postprandial lipemia in moderately hypercholesterolemic subjects: a pilot study

Background

During postprandial state, TG concentration is increasing and HDL cholesterol decreasing, leading to a transitory pro-atherosclerotic profile. Previous studies have reported that bicarbonate water improve postprandial lipemia. The objective of this study was to analyze the effect of a strongly bicarbonated mineral water on lipoprotein levels during fasting and postprandial state.

Methods

A controlled, randomised, double-blind cross-over design was conducted in 12 moderately hypercholesterolemic subjects after a daily ingestion of 1.25 L of mineral (SY) or low mineral water during eight weeks separated by a one week wash-out period. Blood samples were collected in first visit to the hospital (V1) before water consumption (referent or SY) and in a second visit (V2) after eight week water consumption period. The effect of the consumed water was studied in fasting and in postprandial state during ingestion of a meal and 0.5 L of water.

Results

Comparison of data between V1 and V2 after SY consumption showed a significant decrease in triglyceridemia (23%), VLDL TG (31%) and tendency to a decrease of VLDL cholesterol (p = 0.066) at fasting state. Whatever the consumed water during postprandial state, the measurement of total areas under curves did not show a significant difference. No difference was observed between SY and referent water consumption for measured parameters at fasting and postprandial state.

Conclusion

When subjects consumed SY we showed a decrease of their basal TG and VLDLTG. The unexpected absence of effect of high mineralized water on postprandial lipemia, probably related to experimental conditions, is discussed in the discussion section.

A double-blind, placebo-controlled study of the short term effects of a spring water supplemented with magnesium bicarbonate on acid/base balance, bone metabolism and cardiovascular risk factors in postmenopausal women

Background

A number of health benefits including improvements in acid/base balance, bone metabolism, and cardiovascular risk factors have been attributed to the intake of magnesium rich alkaline mineral water. This study was designed to investigate the effects of the regular consumption of magnesium bicarbonate supplemented spring water on pH, biochemical parameters of bone metabolism, lipid profile and blood pressure in postmenopausal women.

Findings

In this double-blind, placebo-controlled, parallel-group, study, 67 postmenopausal women were randomised to receive between 1500 mL and 1800 mL daily of magnesium bicarbonate supplemented spring water (650 mg/L bicarbonate, 120 mg/L magnesium, pH 8.3-8.5) (supplemented water group) or spring water without supplements (control water group) over 84 days. Over this period biomarkers of bone turnover (serum parathyroid hormone (PTH), 1,25-dihydroxyvitamin D, osteocalcin, urinary telopeptides and hydroxyproline), serum lipids (total cholesterol, HDL-cholesterol, LDL-cholesterol and triglycerides), venous and urinary pH were measured together with measurements of standard biochemistry, haematology and urine examinations.

Serum magnesium concentrations and urinary pH in subjects consuming the magnesium bicarbonate supplemented water increased significantly at Day 84 compared to subjects consuming the spring water control (magnesium - p = 0.03; pH - p = 0.018). The consumption of spring water led to a trend for an increase in parathyroid hormone (PTH) concentrations while the PTH concentrations remained stable with the intake of the supplemented spring water. However there were no significant effects of magnesium bicarbonate supplementation in changes to biomarkers of bone mineral metabolism (n-telopeptides, hydroxyproline, osteocalcin and 1,25-dihydroxyvitamin D) or serum lipids or blood pressure in postmenopausal women from Day 0 to Day 84.

Conclusions

Short term regular ingestion of magnesium bicarbonate supplemented water provides a source of orally available magnesium. Long term clinical studies are required to investigate any health benefits.

Trial registration

ACTRN12609000863235

Relationship between tap water hardness, magnesium, and calcium concentration and mortality due to ischemic heart disease or stroke in The Netherlands

BACKGROUND

Conflicting results on the relationship between the hardness of drinking water and mortality related to ischemic heart disease (IHD) or stroke have been reported.

OBJECTIVES

We investigated the possible association between tap water calcium or magnesium concentration and total hardness and IHD mortality or stroke mortality.

METHODS

In 1986, a cohort of 120,852 men and women aged 5569 years provided detailed information on dietary and other lifestyle habits. Follow-up for mortality until 1996 was established by linking data from the Central Bureau of Genealogy and Statistics Netherlands. We calculated tap water hardness for each postal code using information obtained from all pumping stations in the Netherlands. Tap water hardness was categorized as soft [< 1.5 mmol/L calcium carbonate (CaCO3)], medium hard (1.62.0 mmol/L CaCO3), and hard (> 2.0 mmol/L CaCO3). The multivariate case-cohort analysis was based on 1,944 IHD mortality and 779 stroke mortality cases and 4,114 subcohort members.

RESULTS

For both men and women, we observed no relationship between tap water hardness and IHD mortality [hard vs. soft water: hazard ratio (HR) = 1.03; 95% confidence interval (CI), 0.851.28 for men and HR = 0.93; 95% CI, 0.711.21 for women) and stroke mortality (hard vs. soft water HR = 0.90; 95% CI, 0.661.21 and HR = 0.86; 95% CI, 0.621.20, respectively). For men with the 20% lowest dietary magnesium intake, an inverse association was observed between tap water magnesium intake and stroke mortality (HR per 1 mg/L intake = 0.75; 95% CI, 0.610.91), whereas for women with the 20% lowest dietary magnesium intake, the opposite was observed.

CONCLUSIONS

We found no evidence for an overall significant association between tap water hardness, magnesium or calcium concentrations, and IHD mortality or stroke mortality. More research is needed to investigate the effect of tap water magnesium on IHD mortality or stroke mortality in subjects with low dietary magnesium intake.

Survey of trace metals in drinking water supplied to rural populations in the eastern Llanos of Venezuela

To ascertain the water quality for human consumption, chemical parameters such as pH, conductivity and total dissolved calcium, magnesium, iron, aluminum, zinc, copper and manganese were measured during four sampling periods (November 2002; March, May and July 2003) in drinking water wells which supply several forest camps and rural populations located in the eastern Llanos of Venezuela. Copper levels in drinking water in November 2002 were found to be significantly higher (P<0.05) than the other assessed periods. Temporal variations of the other parameters considered were not statistically significant. Calcium and magnesium concentrations were found to be extremely low (mean concentration+/-S.D. of 0.27+/-0.25mg/l for Ca and 0.219+/-0.118 for Mg) during the four sampling periods, probably because of the carbonate bearing scarcity in the soils lithic component. The rest of the metals complied with the Venezuelan and International guidelines of quality criteria for drinking water.

Role of dietary magnesium in cardiovascular disease prevention, insulin sensitivity and diabetes

PURPOSE OF REVIEW

This review summarizes the evidence for benefits of magnesium on metabolic abnormalities, inflammatory parameters, and cardiovascular risk factors and related-potential mechanisms. Controversy due to contrasting results in the literature is also discussed.

RECENT FINDINGS

Increased dietary magnesium intake confers protection against the incidence of diabetes, metabolic syndrome, hypertension, and cardiovascular disease. It ameliorates insulin resistance, serum lipid profiles, and lowers inflammation, endothelial dysfunction, oxidative stress, and platelet aggregability. Magnesium acts as a mild calcium antagonist on vascular smooth muscle tone, and on postreceptor insulin signaling; it is critically involved in energy metabolism, fatty acid synthesis, glucose utilization, ATPase functions, release of neurotransmitters, and endothelial cell function and secretion. Prospective studies, however, have found only a modest effect for dietary magnesium on incident pathologies. Furthermore, magnesium supplementation on glucose metabolism, blood lipid levels, and ischemic heart disease has given inconsistent results.

SUMMARY

There is strong biological plausibility for the direct impact of magnesium intake on metabolic and cardiovascular risk factors, but in-vivo magnesium deficiency might play only a modest role. Reverse causality, the strong association between magnesium and other beneficial nutrients, or the possibility that people who choose magnesium-rich foods are more health-conscious may be confounding factors.

Relationship between serum magnesium values, lipids and anthropometric risk factors

Serum magnesium (SMg) has been reported to negatively correlate with an atherogenic lipid profile in individuals with diabetes mellitus (DM) and metabolic syndrome. This study examines whether the relationships between SMg levels and biochemical and anthropometric risk factors for these conditions are also present in the general adult population.

DESIGN AND METHODS

Biochemical parameters and anthropometric variables were assessed in 1318 healthy adult subjects recruited from the Newfoundland population.

RESULTS

SMg positively correlated with age, and serum phosphate, calcium, albumin, total cholesterol, HDL-cholesterol, LDL-cholesterol and triglyceride levels. SMg negatively correlated with HOMA-beta and percent body fat measured by DEXA. On sub-grouping subjects according to sex, menopausal status or after excluding subjects with DM, only a significant correlation of SMg with albumin, calcium, phosphate, and total cholesterol was common to all. Stepwise linear regression analysis revealed albumin, phosphate, age, total cholesterol, glucose, and body mass index as independent predictors of SMg levels.

CONCLUSIONS

These results indicate that SMg levels positively correlate with total cholesterol and possibly all lipoproteins in a large adult study population which suggests that variation of SMg with serum lipid levels may be different in healthy individuals compared with those with DM. We speculate on a possible binding interaction.

Sodium bicarbonated mineral water decreases postprandial lipaemia in postmenopausal women compared to a low mineral water

The role of bicarbonated mineral waters on lipid metabolism and lipoprotein concentrations in man has scarcely been investigated. The present study aimed to investigate whether drinking sodium bicarbonated mineral water affects postprandial cholesterol and triacylglycerol metabolism in postmenopausal women. In a three-way, randomised, crossover study, eighteen healthy postmenopausal women consumed two sodium bicarbonated mineral waters (bicarbonated mineral water 1 and bicarbonated mineral water 2) and a low mineral water (500 ml of each) with a standard fat-rich meal (4552 kJ; 75.3 g fat). The bicarbonated waters were rich in sodium and bicarbonate and bicarbonated mineral water 1 contained 5.7 times more fluoride than bicarbonated mineral water 2. Fasting blood samples and postprandial blood samples were taken at 30, 60, 120, 240, 360 and 420 min after the end of the meal consumption. Cholesterol and triacylglycerols were determined in serum and chylomicrons. A significant water consumption effect was observed in the total area under the curve (TAUC) of serum and chylomicron triacylglycerols (ANOVA, P=0.008 and P=0.027, respectively). TAUC of serum triacylglycerols for bicarbonated mineral water 2 was significantly lower compared to low mineral water (Bonferroni, P=0.039). Peak concentration of serum triacylglycerols showed a significant water effect (P=0.025). Changes in chylomicron cholesterol were not significantly affected by the type of water. Bicarbonated mineral waters 1 and 2 did not show any significant differences. Drinking sodium bicarbonate-rich mineral waters reduces postprandial lipaemia in healthy postmenopausal women compared to drinking a low mineral water.

Mineral water intake reduces blood pressure among subjects with low urinary magnesium and calcium levels

Background

Several previous epidemiological studies have shown a relation between drinking water quality and death in cardiovascular disease whereas others have not found such a relationship. An intervention study was undertaken to evaluate the effect of water with added magnesium and natural mineral water on blood pressure.

Methods

A group of 70 subjects with borderline hypertension was recruited and consumed 1) a water low in minerals, 2) magnesium enriched water or 3) natural mineral water, in a random, double blind fashion during four weeks.

Results

Among persons with an initial low excretion of magnesium or calcium in the urine, the urinary excretion of magnesium was increased in the groups consuming the two waters containing magnesium after 4 weeks. A significant decrease in blood pressure was found in the group consuming mineral water at 2 and 4 weeks.

Conclusion

The results suggest that minerals taken in water are significant for the body burden and that an intake of mineral water among persons with a low urinary excretion of magnesium or calcium may decrease the blood pressure. Further studies should investigate the extent of mineral deficiency in different populations and the efficiency of different vehicles for supplying minerals, particularly magnesium and calcium.

A sodium-rich carbonated mineral water reduces cardiovascular risk in postmenopausal women

This study was designed to investigate the possible beneficial effects of consuming a sodium-rich carbonated mineral water on lipoprotein metabolism and to determine whether consumption of this water influences endothelial dysfunction (ED) in postmenopausal women. Women included in the study were amenorrheic (>1 y), healthy, and not obese (BMI < 30 kg/m(2)). The subjects did not take estrogen replacement therapy; supplements of vitamins, minerals, and phytoestrogens; or other medications known to affect bone and lipid metabolism. The study consisted of 2 intervention periods of 2 mo each, during which women drank 1 L/d of a control mineral water (low mineral content) for 2 mo followed by the carbonated mineral water, rich in sodium, bicarbonate, and chloride, for 2 mo. Body weight, height, and blood pressure were measured, and BMI was calculated. Blood samples were taken from fasting subjects and serum was analyzed for total cholesterol, HDL-cholesterol, LDL-cholesterol, triacylglycerols, apolipoprotein AI, apolipoprotein B, soluble intercellular cell adhesion molecule-1 (sICAM-1), soluble vascular cell adhesion molecule-1 (sVCAM-1), and glucose. Blood pressure levels did not change throughout the study. Carbonated water intake decreased total cholesterol and LDL-cholesterol levels by 6.8% (P = 0.001) and 14.8% (P < 0.0001), respectively, whereas HDL-cholesterol concentration increased by 8.7% (P = 0.018), compared to the control period. Therefore, cardiovascular disease (CVD) risk indexes (total cholesterol/HDL-cholesterol and LDL-cholesterol/HDL-cholesterol) were markedly reduced (both P < 0.0001). Soluble ICAM-1 and sVCAM-1 levels decreased by 8.4% (P = 0.007) and 14.8% (P = 0.015), respectively. Fasting serum glucose concentration decreased by 6.7% (P < 0.0001). Triacylglycerol levels did not change. Consumption of this sodium rich carbonated water can play a beneficial role in the prevention of CVD and the metabolic syndrome.