Relationship and interaction between sodium and potassium

Gout and Diet: A Comprehensive Review of Mechanisms and Management

Gout is well known as an inflammatory rheumatic disease presenting with arthritis and abnormal metabolism of uric acid. The recognition of diet-induced systemic metabolic pathways have provided new mechanistic insights and potential interventions on gout progression. However, the dietary recommendations for gouty patients generally focus on food categories, with few simultaneous considerations of nutritional factors and systemic metabolism. It is worthwhile to comprehensively review the mechanistic findings and potential interventions of diet-related nutrients against the development of gout, including purine metabolism, urate deposition, and gouty inflammation. Although piecemeal modifications of various nutrients often provide incomplete dietary recommendations, understanding the role of nutritional factors in gouty development can help patients choose their healthy diet based on personal preference and disease course. The combination of dietary management and medication may potentially achieve enhanced treatment effects, especially for severe patients. Therefore, the role of dietary and nutritional factors in the development of gout is systematically reviewed to propose dietary modification strategies for gout management by: (1) reducing nutritional risk factors against metabolic syndrome; (2) supplementing with beneficial nutrients to affect uric acid metabolism and gouty inflammation; and (3) considering nutritional modification combined with medication supplementation to decrease the frequency of gout flares.

Reducing Sodium Consumption in Mexico: A Strategy to Decrease the Morbidity and Mortality of Cardiovascular Diseases

Hypertension (HTN) and cardiovascular diseases (CVD) are important public health problems in Mexico. High sodium intake is linked to high blood pressure and increased risk of developing CVD. International organizations suggest consuming <2 g of sodium/day; however, the Mexican population consumes amounts above what is recommended: 3.1 g/day. Although efforts have been made to mitigate this problem, interventions are needed to improve cardiovascular health. This policy brief offers a short review of the current sodium consumption situation in Mexico and the importance of why decision makers should consider actions to reduce consumption. Recommendations to reduce sodium/salt intake include: Reformulation of ultra-processed-foods, promote the use warning labels, communication campaign, reduce the use of table salt, and monitor sodium intake.

Sodium and Potassium Content of the Most Commonly Available Street Foods in Maputo, Mozambique

Street foods can contribute largely for dietary sodium intake of populations in developing countries. We aimed to assess the variability in sodium and potassium composition of the most commonly available homemade street foods in Maputo city, capital of Mozambique. In a cross-sectional evaluation, researchers canvassed areas with 500-m diameter centered around 20 randomly selected public transport stops, identified all street food vending sites and, in randomly selected sites, purchased 56 samples of the most frequently available homemade foods. Samples were analyzed for sodium and potassium concentrations, using flame photometry. The 56 samples represented main dishes (45 samples of 12 types of food item), sandwiches (8 samples of 5 types of food item) and fried snacks (3 samples of 2 types of food item). Median contents (range), in mg/serving, were 921 (198 to 2525) of sodium and 385 (24 to 1140) of potassium. Median (range) of sodium to potassium molar ratio was 4.1 (1.3 to 41.5). One serving of main dishes was estimated to contribute from 32.1% to 99.9% of the recommended maximum daily sodium intake. The present study shows a large variability and potential for improvement in sodium and potassium contents of homemade foods frequently available in the streets of Maputo city.

Dietary Sodium and Potassium Intake: Data from the Mexican National Health and Nutrition Survey 2016

Population studies have demonstrated an association between sodium and potassium intake and blood pressure levels and lipids. The aim of this study was to describe the dietary intake and contribution of sodium and potassium to the Mexican diet, and to describe its association with nutrition status and clinical characteristics. We analyzed a national survey with 4219 participants. Dietary information was obtained with a 24-h recall. Foods and beverages were classified according to level of processing. The mean intake (mg/d) of Na was 1512 in preschool children, 2844 in school-age children, 3743 in adolescents, and 3132 in adults. The mean intake (mg/d) of K was 1616 in preschool children, 2256 in school-age children, 2967 in adolescents, and 3401 in adults. Processed and ultra-processed foods (UPF) contribute 49% of Na intake in preschool children, 50% in school-age children, 47% in adolescents, and 39% in adults. Adults with high Na intake had lower serum concentrations of cholesterol, HDL-c, and LDL-c. A significant proportion of the Mexican population has a high intake of Na (64-82%) and low K (58-73%). Strategies to reduce Na and increase K intake need to reduce the possibility of having high BP and serum lipid disturbances.

The Role of Mineral Deficiencies in Insulin Resistance and Obesity

Minerals are critical for maintaining overall health. These tiny chemical compounds are responsible for enzymatic activation, maintaining healthy teeth and bones, regulating energy metabolism, enhancing immunity, and aiding muscle and brain function. However, mineral deficiency in the form of inadequate or under nourished intake affects millions of people throughout the world, with well-documented adverse health consequences of malnutrition. Conversely, mineral deficiency may also be a risk factor for Insulin Resistance (IR) and obesity. This review focuses on another, more "less discussed" form of malnutrition, namely mineral deficiency and its contribution to metabolic disorders. At the cellular level, minerals maintain not only molecular communication but also trigger several key biochemical pathways. Disturbances in these processes due to mineral insufficiency may gradually lead to metabolic disorders such as insulin resistance, pre-diabetes, and central obesity, which might lead to renal failure, cardiac arrest, hepatic carcinoma, and various neurodegenerative diseases. Here we discuss the burden of disease promoted by mineral deficiencies and the medical, social, and economic consequences. Mineral deficiency-mediated IR and obesity have a considerable negative impact on individual well-being, physical consideration, and economic productivity. We discuss possible molecular mechanisms of mineral deficiency that may lead to IR and obesity and suggest strategies to counter these metabolic disorders. To protect mankind from mineral nutrient deficiencies, the key is to take a variety of foods in reasonable quantities, such as organic and pasture-raised eggs, low fat dairy, and grass-fed and finished meats, insecticide, and pesticide-free vegetables and fruits.

Reduced-sodium cheeses: Implications of reducing sodium chloride on cheese quality and safety

Sodium chloride (NaCl) universally well-known as table salt is an ancient food additive, which is broadly used to increase the storage stability and the palatability of foods. Though, in recent decades, use of table salt in foods is a major concern among the health agencies of the world owing to ill effects of sodium (Na) that are mostly linked to hypertension and cardiovascular diseases. As a result, food scientists are working to decrease the sodium content in food either by decreasing the rate of NaCl addition or by partial or full replacement of NaCl with other suitable salts like potassium chloride (KCl), calcium chloride (CaCl₂ ), or magnesium chloride (MgCl₂ ). However, in cheese, salt reduction is difficult to accomplish owing to its multifaceted role in cheese making. Considering the significant contribution in dietary salt intake (DSI) from cheese, researchers across the globe are exploring various technical interventions to develop reduced-sodium cheeses (RSCs) without jeopardizing the quality and safety of cheeses. Thus, the purpose of this study is to provide an insight of NaCl reduction on sensory, physicochemical, and technofunctional attributes of RSCs with an aim to explore various strategies for salt reduction without affecting the cheese quality and safety. The relationship between salt reduction and survival of pathogenic and spoilage-causing microorganisms and growth of RSCs microflora is also discussed. Based on the understanding of conceptual and applied information on the complex changes that occur in the development of RSCs, the quality and safety of RSCs can be accomplished effectively in order to reduce the DSI from cheese.

Higher Ca and Na content in the hair of obese people in Poland

The authors of this paper decided to check whether the content of selected minerals in human hair is projected into the nutritional status of the body expressed as the BMI. The study focused on evaluating the content of calcium, sodium, potassium and magnesium in the hair of 7845 individuals in relation to their BMI. 5126 women and 2719 men aged from 18 to 92, domiciled throughout Poland, were involved in the study. Hair samples were taken from several points of the occipital scalp. Ca, Na, K and Mg in the hair were determined using inductively coupled plasma optical emission spectrometry (ICP-OES). The content of Ca and Na in the hair of obese people (>30.0 kg·m²) was higher (323 mg·kg^-1 and 180 mg·kg^-1) in comparison with the groups of people with normal body weight and those grade 2 underweight (<16.9 kg·m²): 191 mg·kg^-1 and 103 mg·kg^-1 respectively. The highest level of K (317 mg·kg^-1) was found in the hair of people classed as grade 2 underweight. The body mass index caused no differentiation in the content of Mg in hair. Positive correlations were found between Ca-Na, Ca-Mg and Na-Mg and between the BMI of the subjects and the content of Ca in hair (R = 0.163; p < 0.01) and between the BMI and the content of Na (R = 0.191; p < 0.01). On the other hand, a negative relation between K and the BMI was correlated only to an infinitesimal degree (R = -0.030, p < 0.01). The results point to a relationship between the body mass index and the content of Ca, Na and K in the hair of adults.

Joint association of urinary sodium and potassium excretion with cardiovascular events and mortality: prospective cohort study

OBJECTIVE

To evaluate the joint association of sodium and potassium urinary excretion (as surrogate measures of intake) with cardiovascular events and mortality, in the context of current World Health Organization recommendations for daily intake (<2.0 g sodium, >3.5 g potassium) in adults.

DESIGN

International prospective cohort study.

SETTING

18 high, middle, and low income countries, sampled from urban and rural communities.

PARTICIPANTS

103 570 people who provided morning fasting urine samples.

MAIN OUTCOME MEASURES

Association of estimated 24 hour urinary sodium and potassium excretion (surrogates for intake) with all cause mortality and major cardiovascular events, using multivariable Cox regression. A six category variable for joint sodium and potassium was generated: sodium excretion (low (<3 g/day), moderate (3-5 g/day), and high (>5 g/day) sodium intakes) by potassium excretion (greater/equal or less than median 2.1 g/day).

RESULTS

Mean estimated sodium and potassium urinary excretion were 4.93 g/day and 2.12 g/day, respectively. After a median follow-up of 8.2 years, 7884 (6.1%) participants had died or experienced a major cardiovascular event. Increasing urinary sodium excretion was positively associated with increasing potassium excretion (unadjusted r=0.34), and only 0.002% had a concomitant urinary excretion of <2.0 g/day of sodium and >3.5 g/day of potassium. A J-shaped association was observed of sodium excretion and inverse association of potassium excretion with death and cardiovascular events. For joint sodium and potassium excretion categories, the lowest risk of death and cardiovascular events occurred in the group with moderate sodium excretion (3-5 g/day) and higher potassium excretion (21.9% of cohort). Compared with this reference group, the combinations of low potassium with low sodium excretion (hazard ratio 1.23, 1.11 to 1.37; 7.4% of cohort) and low potassium with high sodium excretion (1.21, 1.11 to 1.32; 13.8% of cohort) were associated with the highest risk, followed by low sodium excretion (1.19, 1.02 to 1.38; 3.3% of cohort) and high sodium excretion (1.10, 1.02 to 1.18; 29.6% of cohort) among those with potassium excretion greater than the median. Higher potassium excretion attenuated the increased cardiovascular risk associated with high sodium excretion (P for interaction=0.007).

CONCLUSIONS

These findings suggest that the simultaneous target of low sodium intake (<2 g/day) with high potassium intake (>3.5 g/day) is extremely uncommon. Combined moderate sodium intake (3-5 g/day) with high potassium intake is associated with the lowest risk of mortality and cardiovascular events.

Association of soil potassium and sodium concentrations with spatial disparities of prevalence and mortality rates of hypertensive diseases in the USA

Crop available soil potassium is generally low and on the decline in the southeastern states of the USA because of the increasing crop and runoff removal and decreasing application of potassium fertilizer. Hypertension-related mortality rates are also high in the southeastern states and are on the rise. Among 41 elements analyzed from 4856 sites across all 48 states, potassium is identified as the only independent element whose soil concentration has significant association with spatial disparities of essential hypertension and hypertension-related mortality rates in the 48 states between 1999 and 2014. Essential hypertension and hypertension-related mortality rates of the 6 states with the lowest soil potassium concentration are about 50-26% higher than that of the 6 states with the highest soil potassium concentration in the 48 states (RR: 1.50, 1.26, low CI 95% 1.47, 1.25 and upper CI 95% 1.53, 1.27, respectively). Though sodium was not identified as an independent factor, an apparent significant inverse correlation exists between hypertension prevalence rates and soil sodium concentration in the 48 states (r = - 0.66, p = 0.00). There likely has been a decline of potassium in USA produces per unit weight over time and a likely association between this decline and increasing hypertension rate, particularly in the southeastern states. Hence, results of this study suggest the need of increasing potassium intakes for reducing hypertension-related mortality rates in the southeastern states. Results of this study also support further examination of potential benefits of sodium from mixture of non-chloride salts in natural produces.

The technical report on sodium intake and cardiovascular disease in low- and middle-income countries by the joint working group of the World Heart Federation, the European Society of Hypertension and the European Public Health Association

Ingestion of sodium is essential to health, but excess sodium intake is a risk factor for hypertension and cardiovascular disease. Defining an optimal range of sodium intake in populations has been challenging and controversial. Clinical trials evaluating the effect of sodium reduction on blood pressure have shown blood pressure lowering effects down to sodium intake of less than 1.5 g/day. Findings from these blood pressure trials form the basis for current guideline recommendations to reduce sodium intake to less than 2.3 g/day. However, these clinical trials employed interventions that are not feasible for population-wide implementation (i.e. feeding studies or intensive behavioural interventions), particularly in low and middle-income countries. Prospective cohort studies have identified the optimal range of sodium intake to reside in the moderate range (3-5 g/day), where the risk of cardiovascular disease and death is lowest. Therefore, there is consistent evidence from clinical trials and observational studies to support reducing sodium intake to less than 5 g/day in populations, but inconsistent evidence for further reductions below a moderate intake range (3-5 g/day). Unfortunately, there are no large randomized controlled trials comparing low sodium intake (< 3 g/day) to moderate sodium intake (3-5 g/day) in general populations to determine the net clinical effects of low sodium intake. Until such trials are completed, it is likely that controversy about optimal sodium intake range will continue. This working group calls for the completion of large definitive clinical trials to clarify the range of sodium intake for optimal cardiovascular health within the moderate to low intake range. We support interventions to reduce sodium intake in populations who consume high sodium intake (> 5 g/day), which should be embedded within an overall healthy dietary pattern.

Age- and gender-dependent associations of blood pressure and serum sodium and potassium-renal and extrarenal regulations

Association analyses between blood pressure (BP) and serum sodium and potassium for 14,657 men and 16,977 women between ages 12 and 85 years show that responses of BP to serum sodium and potassium are age and gender dependent. The data were from the National Health and Nutrition Examination Survey between 2003 and 2014. Associations between serum sodium and BP are positive only for advanced age groups and for serum sodium level greater than 139-140 mmol/L in less advanced groups. These positive associations can be explained by traditional renal-centered mechanism. Inverse associations between systolic BP and serum sodium exist when sodium is less than ∼140 mmol/L in less advanced age groups (<60 for men and <70 for women). These inverse associations can partially be explained by the extrarenal regulatory mechanism in which sodium storage in negatively charged glycosaminoglycans in the interstitium may be involved. Associations of high serum potassium and low BP are consistent and exist in most age groups. Effect of potassium on systolic BP and diastolic BP are more prominent in less advanced age groups. Age-dependent associations between sodium and BP support the theory that sodium homeostasis in the body may not be regulated by renal-centered responses alone. There might be regulation of an extrarenal system in which sodium attraction by negatively charged glycosaminoglycans plays a role.

Effects of Sodium Reduction and the DASH Diet in Relation to Baseline Blood Pressure

BACKGROUND

Both sodium reduction and the DASH (Dietary Approaches to Stop Hypertension) diet, a diet rich in fruits, vegetables, and low-fat dairy products, and reduced in saturated fat and cholesterol, lower blood pressure. The separate and combined effects of these dietary interventions by baseline blood pressure (BP) has not been reported.

OBJECTIVES

The authors compared the effects of low versus high sodium, DASH versus control, and both (low sodium-DASH vs. high sodium-control diets) on systolic blood pressure (SBP) by baseline BP.

METHODS

In the DASH-Sodium (Dietary Patterns, Sodium Intake and Blood Pressure) trial, adults with pre- or stage 1 hypertension and not using antihypertensive medications, were randomized to either DASH or a control diet. On either diet, participants were fed each of 3 sodium levels (50, 100, and 150 mmol/day at 2,100 kcal) in random order over 4 weeks separated by 5-day breaks. Strata of baseline SBP were <130, 130 to 139, 140 to 149, and ≥150 mm Hg.

RESULTS

Of 412 participants, 57% were women, and 57% were black; mean age was 48 years, and mean SBP/diastolic BP was 135/86 mm Hg. In the context of the control diet, reducing sodium (from high to low) was associated with mean SBP differences of -3.20, -8.56, -8.99, and -7.04 mm Hg across the respective baseline SBP strata listed (p for trend = 0.004). In the context of high sodium, consuming the DASH compared with the control diet was associated with mean SBP differences of -4.5, -4.3, -4.7, and -10.6 mm Hg, respectively (p for trend = 0.66). The combined effects of the low sodium-DASH diet versus the high sodium-control diet on SBP were -5.3, -7.5, -9.7, and -20.8 mm Hg, respectively (p for trend <0.001).

CONCLUSIONS

The combination of reduced sodium intake and the DASH diet lowered SBP throughout the range of pre- and stage 1 hypertension, with progressively greater reductions at higher levels of baseline SBP. SBP reductions in adults with the highest levels of SBP (≥150 mm Hg) were striking and reinforce the importance of both sodium reduction and the DASH diet in this high-risk group. Further research is needed to determine the effects of these interventions among adults with SBP ≥160 mm Hg. (Dietary Patterns, Sodium Intake and Blood Pressure [DASH-Sodium]; NCT00000608).

Urinary Sodium and Potassium Excretion and Dietary Sources of Sodium in Maputo, Mozambique

This study aimed to evaluate the urinary excretion of sodium and potassium, and to estimate the main food sources of sodium in Maputo dwellers. A cross-sectional evaluation of a sample of 100 hospital workers was conducted between October 2012 and May 2013. Sodium and potassium urinary excretion was assessed in a 24-h urine sample; creatinine excretion was used to exclude unlikely urine values. Food intake in the same period of urine collection was assessed using a 24-h dietary recall. The Food Processor Plus^® was used to estimate sodium intake corresponding to naturally occurring sodium and sodium added to processed foods (non-discretionary sodium). Salt added during culinary preparations (discretionary sodium) was computed as the difference between urinary sodium excretion and non-discretionary sodium. The mean (standard deviation) urinary sodium excretion was 4220 (1830) mg/day, and 92% of the participants were above the World Health Organization (WHO) recommendations. Discretionary sodium contributed 60.1% of total dietary sodium intake, followed by sodium from processed foods (29.0%) and naturally occurring sodium (10.9%). The mean (standard deviation) urinary potassium excretion was 1909 (778) mg/day, and 96% of the participants were below the WHO potassium intake recommendation. The mean (standard deviation) sodium to potassium molar ratio was 4.2 (2.4). Interventions to decrease sodium and increase potassium intake are needed in Mozambique.

Sodium and Potassium Intake in Healthy Adults in Thessaloniki Greater Metropolitan Area-The Salt Intake in Northern Greece (SING) Study

A reduction in population sodium (as salt) consumption is a global health priority, as well as one of the most cost-effective strategies to reduce the burden of cardiovascular disease. High potassium intake is also recommended to reduce cardiovascular disease. To establish effective policies for setting targets and monitoring effectiveness within each country, the current level of consumption should be known. Greece lacks data on actual sodium and potassium intake. The aim of the present study was therefore to assess dietary salt (using sodium as biomarker) and potassium intakes in a sample of healthy adults in northern Greece, and to determine whether adherence to a Mediterranean diet is related to different sodium intakes or sodium-to-potassium ratio. A cross-sectional survey was carried out in the Thessaloniki greater metropolitan area (northern Greece) (n = 252, aged 18-75 years, 45.2% males). Participants' dietary sodium and potassium intakes were determined by 24-hour urinary sodium and potassium excretions. In addition, we estimated their adherence to Mediterranean diet by the use of an 11-item MedDietScore (range 0-55). The mean sodium excretion was 175 (SD 72) mmol/day, equivalent to 4220 (1745) mg of sodium or 10.7 (4.4) g of salt per day, and the potassium excretion was 65 (25) mmol/day, equivalent to 3303 (1247) mg per day. Men had higher sodium and potassium excretions compared to women. Only 5.6% of the sample had salt intake <5 g/day, which is the target intake recommended by the World Health Organization. Mean sodium-to-potassium excretion ratio was 2.82 (1.07). There was no significant difference in salt or potassium intake or their ratio across MedDietScore quartiles. No significant relationships were found between salt intake and adherence to a Mediterranean diet, suggesting that the perception of the health benefits of the Mediterranean diet does not hold when referring to salt consumption. These results suggest the need for a larger, nation-wide survey on salt intake in Greece and underline the importance of continuation of salt reduction initiatives in Greece.

Natural sea salt consumption confers protection against hypertension and kidney damage in Dahl salt-sensitive rats

Although sea salts are widely available to consumers nowadays, whether its consumption over refined salt has any real health benefits is largely unknown. This study was conducted to compare hypertension-inducing propensity of natural sea salt (SS) to refined salt (RS) in a well-established animal model of hypertension. Five groups of male Dahl salt-sensitive rats were fed rat chow diet supplemented with various amounts of salt for 15 weeks. The groups were: control (CON, n = 10), 4% RS (RS4), 4% SS (SS4), 8% RS (RS8), 8% SS (SS8) (n = 12 for each group). After 15 weeks, both SS4 and SS8 groups had significantly lower systolic (SBP) and diastolic blood pressure (DBP) compared to RS4 and RS8 rats, respectively. RS8 rats had markedly higher SBP and DBP compared to all other groups. Echocardiography just prior to sacrifice showed abnormalities in RS4, SS8 and RS8 hearts, while CON and SS4 hearts displayed normal measurements. Plasma renin and aldosterone levels of high salt groups were lower than those of CON, and serum electrolytes were similar amongst all groups. Abnormal kidney pathology and high glomerulosclerosis index scores were seen in RS4 and RS8 rats, but SS4 and SS8 kidneys showed relatively normal morphology similar to CON kidneys. Our findings show that consumption of natural sea salt induces less hypertension compared to refined salt in the Dahl salt-sensitive rat.

Effects of Salt Loading on Plasma Osteoprotegerin Levels and Protective Role of Potassium Supplement in Normotensive Subjects

BACKGROUND

Excess dietary salt is strongly correlated with cardiovascular disease, morbidity, and mortality. Conversely, potassium likely elicits favorable effects on cardiovascular disorders. In epidemiological studies, increased plasma osteoprotegerin (OPG) concentrations are associated with atherosclerosis and vascular deaths. Our study was designed to examine the effects of salt intake and potassium supplementation on plasma OPG levels in normotensive subjects.Methods and Results:The 18 normotensive subjects were selected from a rural community in China. They were sequentially maintained on low-salt diet for 7 days (3 g/day, NaCl), high-salt diet for 7 days (18 g/day), and high-salt diet with potassium supplementation for 7 days (18 g/day of NaCl+4.5 g/day of KCl). High-salt intake enhanced plasma OPG levels (252.7±13.9 vs. 293.4±16.1 pg/mL). This phenomenon was abolished through potassium supplementation (293.4±16.1 vs. 235.1±11.3 pg/mL). Further analyses revealed that the OPG concentration positively correlated with 24-h urinary sodium excretion (r=0.497, P<0.01). By contrast, OPG concentration negatively correlated with 24-h urinary potassium excretion (r=0.594, P<0.01).

CONCLUSIONS

Salt loading can enhance the production of circulating OPG. Potassium supplementation can reverse the effects of excessive OPG. Our study results may improve our understanding of the roles of salt and potassium in the risk of cardiovascular disorders.

Sodium and potassium urinary excretion and dietary intake: a cross-sectional analysis in adolescents

Background

Hypertension is the leading cause for heart disease and stroke, for mortality and morbidity worldwide, and a high sodium-to-potassium intake ratio is considered a stronger risk factor for hypertension than sodium alone.

Objective

This study aims to evaluate sodium and potassium urinary excretion, and assess the food sources of these nutrients in a sample of Portuguese adolescents.

Design

A cross-sectional study with a sample of 250 Portuguese adolescents. Sodium and potassium excretion were measured by one 24-h urinary collection, and the coefficient of creatinine was used to validate completeness of urine collections. Dietary sources of sodium and potassium were assessed using a 24-h dietary recall.

Results

Valid urine collections were provided by 200 adolescents (118 girls) with a median age of 14.0 in both sexes (p=0.295). Regarding sodium, the mean urinary excretion was 3,725 mg/day in boys and 3,062 mg/day in girls (p<0.01), and 9.8% of boys and 22% of girls met the World Health Organization (WHO) recommendations for sodium intake. Concerning potassium, the mean urinary excretion was 2,237 mg/day in boys and 1,904 mg/day in girls (p<0.01), and 6.1% of boys and 1.7% of girls met the WHO recommendations for potassium intake. Major dietary sources for sodium intake were cereal and cereal products (41%), meat products (16%), and milk and milk products (11%); and for potassium intake, main sources were milk and milk products (21%), meat products (17%), and vegetables (15%).

Conclusions

Adolescents had a high-sodium and low-potassium diet, well above the WHO recommendations. Health promotion interventions are needed in order to decrease sodium and increase potassium intake.

Dietary quality differs by consumption of meals prepared at home vs. outside in Korean adults

BACKGROUND/OBJECTIVES

Eating out has been reported to have negative effects on nutritional status. However, eating out can include meals prepared at home and eaten outside. Conversely, meals eaten at home can be brought from outside, as take-out and home deliveries have become common in Korea. Thus, we tested whether or not meal preparation location influences daily diet quality.

SUBJECTS/METHODS

From the Korea National Health and Nutrition Examination Survey (KNHANES) 2007-2009, 4,915 Korean adults (20-64 years) were classified into two groups: home-made meal group (HMG), who ate ≥ 2 meals per day prepared at home (n = 4,146), and non-home-made meal group (NHMG), who ate ≥ 2 meals per day prepared outside home (n = 769). Daily diet quality was determined by energy intake, nutrient intake, Dietary Variety Score (DVS), and Diet Diversity Score (DDS).

RESULTS

Compared to the HMG, the NHMG was more likely to consist of men, single, employed, educated and of a higher economic status (all, P < 0.01). The NHMG showed higher energy intakes (1,776 vs. 2,116 kcal/day) with higher percentages of energy from protein (15 vs. 23%) and fat (14 vs. 16%) and lower intakes of dietary fiber, phosphorus, potassium, niacin, and vitamin C (all, P < 0.01) than the HMG, with some variations among age groups. The NHMG tended to consume foods prepared by frying and grilling and had more one-dish meals such as bibimbap, noodles, and dumplings but also showed higher dietary diversity.

CONCLUSIONS

It should be noted that home-made meals do not necessarily guarantee a healthy diet, and the effects of meal preparation location on nutritional status might vary depending on socio-demographic characteristics.

Assessment of influence of pro-health nutrition education and resulting changes of nutrition behavior of women aged 65-85 on their body content

INTRODUCTION

One of systemic changes connected to body ageing is the change of body content and the possibility of formation and/or intensification of insulin resistance, dyslipidemia and hypertension symptoms.

MATERIAL AND METHODS

The research was conducted on 68 women aged 65-85 with body mass index (BMI) of 25.3 to 44.5 kg/m(2) who have been educated for four months. The energy and nutritive value of 204 daily food rations (DFRs) was evaluated twice: first days of October and - after the diet correction and implementation of the basic rules - from the end of January. The measurements, anthropometric and body content (in 35 women under research) with the bio-impedance method was checked twice - before and after completing the education.

RESULTS

After completing the education, there was a statistically significant increase in consumption of grain products, fermented milk products, potatoes, fruit and vegetables, as well as seeds of legumes. Consumption of meat and cold meats, sugar and sweets significantly decreased. In the course of education, an individual-specific decrease in body mass of the participants was noticed, which found its reflection in positive changes of the anthropometric indicators value. A significant decrease in fat content in bodies of women under research was also noticed, which was accompanied by a slight increase in fat-free body mass and water.

CONCLUSIONS

The four-month pro-health education of women influenced changes in improper nutrition habits resulting in, besides the improvement of organism functions and well-being of women under research, body mass loss and changes in content of the body.

Sodium intake and cardiovascular health

Sodium is an essential nutrient. Increasing sodium intake is associated with increasing blood pressure, whereas low sodium intake results in increased renin and aldosterone levels. Randomized controlled trials have reported reductions in blood pressure with reductions in sodium intake, to levels of sodium intake <1.5 g/d, and form the evidentiary basis for current population-wide guidelines recommending low sodium intake. Although low sodium intake (<2.0 g/d) has been achieved in short-term feeding clinical trials, sustained low sodium intake has not been achieved by any of the longer term clinical trials (>6-month duration). It is assumed that the blood pressure-lowering effects of reducing sodium intake to low levels will result in large reductions in cardiovascular disease globally. However, current evidence from prospective cohort studies suggests a J-shaped association between sodium intake and cardiovascular events, based on studies from >300 000 people, and suggests that the lowest risk of cardiovascular events and death occurs in populations consuming an average sodium intake range (3-5 g/d). The increased risk of cardiovascular events associated with higher sodium intake (>5 g/d) is most prominent in those with hypertension. A major deficit in the field is the absence of large randomized controlled trials to provide definitive evidence on optimal sodium intake for preventing cardiovascular events. Pending such trials, current evidence would suggest a recommendation for moderate sodium intake in the general population (3-5 g/d), with targeting the lower end of the moderate range among those with hypertension.

Claudins and the kidney

Claudins are tight-junction membrane proteins that function as both pores and barriers in the paracellular pathway in epithelial cells. In the kidney, claudins determine the permeability and selectivity of different nephron segments along the renal tubule. In the proximal tubule, claudins have a role in the bulk reabsorption of salt and water. In the thick ascending limb, claudins are important for the reabsorption of calcium and magnesium and are tightly regulated by the calcium-sensing receptor. In the distal nephron, claudins need to form cation barriers and chloride pores to facilitate electrogenic sodium reabsorption and potassium and acid secretion. Aldosterone and the with-no-lysine (WNK) proteins likely regulate claudins to fine-tune distal nephron salt transport. Genetic mutations in claudin-16 and -19 cause familial hypomagnesemic hypercalciuria with nephrocalcinosis, whereas polymorphisms in claudin-14 are associated with kidney stone risk. It is likely that additional roles for claudins in the pathogenesis of other types of kidney diseases have yet to be uncovered.

Dietary potassium intake and renal handling, and their impact on the cardiovascular health of normotensive afro-caribbeans

OBJECTIVE

Recent nutritional profiles of dietary intake have indicated a shift from the ancient diet to the Western diet. The ancient diet provided a high potassium and low sodium intake, which in turn leads to sodium conservation and potassium excretion. This change in the dietary intake is expected to affect potassium and sodium handling in the kidneys. Numerous studies have been done to emphasize the importance of sodium handling by the kidneys and its impact on cardiovascular health. This study will investigate potassium intake and handling, and its impact on the cardiovascular health of a sample of normotensive Afro-Caribbeans by the possible modulation of the renin angiotensin aldosterone system (RAAS).

METHODS

A sample of 51 normotensive Afro-Caribbean participants was recruited for the study. Participants were observed over a two-day period in which they were given a 24-hour ambulatory blood pressure monitor and a container to collect blood pressure data and a 24-hour urine sample. Anthropometric measurements were noted. Urinary electrolytes and supine plasma renin activity (PRA) were determined from the 24-hour urine collection and a blood sample. Dietary potassium intake was estimated based on dietary intake observations and calculated based on the urinary potassium excretion. SPSS version 19 was used to analyse the data to make inferences.

RESULTS

The daily potassium intake was observed to be 2.95 g/day and measured intake from the urinary potassium was between 4.95 and 7.32 g/day. Urinary potassium excretion was 3.66 (± 1.40) g/day. The urinary potassium excretion in the Afro-Caribbean sample in Barbados was higher than the other population samples. The averaged PRA of the participants (supine) was 0.778 (± 1.072) ng/mL/hour. The averaged nocturnal systolic blood pressure dip of the participants was 5.97 (± 4.324) %. There was no significant correlation between urinary potassium excretion, blood pressure, nocturnal systolic blood pressure dip and PRA.

CONCLUSIONS

The Afro-Caribbean sample has an inadequate daily potassium intake based on the observed intake and recommended values, with a high urinary excretion of the electrolyte compared to other values in the literature. This high potassium excretion could have been partly due to low plasma renin activity levels in the study participants. As a possible consequence, an increase in the nocturnal peripheral resistance is a likely cause for the diminished systolic dip. The lack of correlations between dietary potassium excretion and the blood pressure parameters does not allow any firm inference of the electrolyte's handling and its impact on cardiovascular health in the normotensive Afro-Caribbean participants. However, further research is needed to get a more accurate daily potassium intake value, and a more statistically robust sample to assess whether potassium handling and blood pressure would be affected by a change in potassium intake.

Comprehensive assessment of the association of WNK4 polymorphisms with hypertension: evidence from a meta-analysis

The relationship between with-no-lysine [K] kinase 4 (WNK4) gene polymorphisms and hypertension has been widely investigated, However, the studies yielded contradictory results. To evaluate these inconclusive findings comprehensively, we therefore performed a meta-analysis. Ten articles encompassing 16 independent case-control studies with 6089 hypertensive cases and 4881 normotensive controls were selected for this meta-analysis. Four WNK4 gene polymorphisms were identified (G1155942T, G1156666A, T1155547C, and C6749T). The results showed statistically significant associations of G1155942T polymorphism (allelic genetic model: odds ration or OR = 1.62, 95% confidence interval or CI: 1.11–2.38, P = 0.01; dominant model: OR = 1.85, 95% CI: 1.07–3.19, P = 0.03) and C6749T polymorphism (allele contrast: OR = 2.04, 95% CI: 1.60–2.59, P<0.01; dominant model: OR = 2.04, 95%CI: 1.59–2.62, P<0.01; and homozygous model: OR = 5.01, 95% CI: 1.29–19.54, P = 0.02) with hypertension risk. However, neither C1155547T nor G1156666A was associated significantly with hypertension susceptibility. In conclusion, this meta-analysis suggested that WNK4 G1155942T and C6749T gene polymorphisms may contribute to the susceptibility and development of hypertension. Further well-designed studies with larger sample size are required to elucidate the association of WNK4 gene multiple polymorphisms with hypertension risk.

Urinary sodium excretion and dietary sources of sodium intake in Chinese postmenopausal women with prehypertension

Background

Reducing salt intake in communities is one of the most effective and affordable public health strategies to prevent hypertension, stroke and renal disease. The present study aimed to determine the sodium intake in Hong Kong Chinese postmenopausal women and identify the major food sources contributing to sodium intake and urine excretion.

Methods

This was a cross-sectional study among 655 Chinese postmenopausal women with prehypertension who were screened for a randomized controlled trial. Data collection included 24 h urine collection for the measurement of sodium, potassium and creatinine, 3-day dietary records, anthropometric measures and questionnaire survey on demographic data and dietary habits.

Results

The average salt intake estimated from urinary excretion was 7.8±3.2 g/d with 82.1% women above WHO recommendation of 5 g/day. Food groups as soup (21.6%), rice and noodles (13.5%), baked cereals (12.3%), salted/preserved foods (10.8%), Chinese dim sum (10.2%) and sea foods (10.1%) were the major contributors of non-discretionary salt. Discretionary salt use in cooking made a modest contribution to overall intake. Vegetable and fruit intake, age, sodium intake from salted foods, sea foods and soup were the independent determinants of urinary sodium excretion.

Conclusions

Our data revealed a significant room for reduction of the sodium intake. Efforts to reduce sodium from diets in Hong Kong Chinese postmenopausal women should focus on both processed foods and discretionary salt during cooking. Sodium reduction in soup and increase in fruit intake would be potentially effective strategy for reducing sodium.

Association of the neighborhood retail food environment with sodium and potassium intake among US adults

INTRODUCTION

High sodium intake and low potassium intake, which can contribute to hypertension and risk of cardiovascular disease, may be related to the availability of healthful food in neighborhood stores. Despite evidence linking food environment with diet quality, this relationship has not been evaluated in the United States. The modified retail food environment index (mRFEI) provides a composite measure of the retail food environment and represents the percentage of healthful-food vendors within a 0.5 mile buffer of a census tract.

METHODS

We analyzed data from 8,779 participants in the National Health and Nutrition Examination Survey, 2005-2008. By using linear regression, we assessed the relationship between mRFEI and sodium intake, potassium intake, and the sodium-potassium ratio. Models were stratified by region (South and non-South) and included participant and neighborhood characteristics.

RESULTS

In the non-South region, higher mRFEI scores (indicating a more healthful food environment) were not associated with sodium intake, were positively associated with potassium intake (P [trend] = .005), and were negatively associated with the sodium-potassium ratio (P [trend] = .02); these associations diminished when neighborhood characteristics were included, but remained close to statistical significance for potassium intake (P [trend] = .05) and sodium-potassium ratio (P [trend] = .07). In the South, mRFEI scores were not associated with sodium intake, were negatively associated with potassium intake (P [trend] = < .001), and were positively associated with sodium-potassium ratio (P [trend] = .01). These associations also diminished after controlling for neighborhood characteristics for both potassium intake (P [trend] = .03) and sodium-potassium ratio (P [trend] = .40).

CONCLUSION

We found no association between mRFEI and sodium intake. The association between mRFEI and potassium intake and the sodium-potassium ratio varied by region. National strategies to reduce sodium in the food supply may be most effective to reduce sodium intake. Strategies aimed at the local level should consider regional context and neighborhood characteristics.

[Evolution of the diet from the paleolithic to today: progress or regress?]

The changes in eating habits and decreased physical activity have been responsible for part of the high prevalence of chronic diseases such as hypertension or diabetes, currently observed in the so-called civilized societies. These diseases are less prevalent in previous civilizations and several decades of nutrition research have enabled better understanding of the eating habits of our ancestors, and have demonstrated the value of diet called "Mediterranean or Paleolithic". This review provides an update on the latest research. What dietary changes since the Paleolithic period, and finally how can we adapt our current diet? Several animal studies or human clinical demonstrate the value of historical research and nutrition.

Sodium and potassium intakes among US adults: NHANES 2003-2008

BACKGROUND

The American Heart Association (AHA), Institute of Medicine (IOM), and US Departments of Health and Human Services and Agriculture (USDA) Dietary Guidelines for Americans all recommend that Americans limit sodium intake and choose foods that contain potassium to decrease the risk of hypertension and other adverse health outcomes.

OBJECTIVE

We estimated the distributions of usual daily sodium and potassium intakes by sociodemographic and health characteristics relative to current recommendations.

DESIGN

We used 24-h dietary recalls and other data from 12,581 adults aged ≥20 y who participated in NHANES in 2003-2008. Estimates of sodium and potassium intakes were adjusted for within-individual day-to-day variation by using measurement error models. SEs and 95% CIs were assessed by using jackknife replicate weights.

RESULTS

Overall, 99.4% (95% CI: 99.3%, 99.5%) of US adults consumed more sodium daily than recommended by the AHA (<1500 mg), and 90.7% (89.6%, 91.8%) consumed more than the IOM Tolerable Upper Intake Level (2300 mg). In US adults who are recommended by the Dietary Guidelines to further reduce sodium intake to 1500 mg/d (ie, African Americans aged ≥51 y or persons with hypertension, diabetes, or chronic kidney disease), 98.8% (98.4%, 99.2%) overall consumed >1500 mg/d, and 60.4% consumed >3000 mg/d-more than double the recommendation. Overall, <2% of US adults and ~5% of US men consumed ≥4700 mg K/d (ie, met recommendations for potassium).

CONCLUSION

Regardless of recommendations or sociodemographic or health characteristics, the vast majority of US adults consume too much sodium and too little potassium.

The alkaline diet: is there evidence that an alkaline pH diet benefits health?

This review looks at the role of an alkaline diet in health. Pubmed was searched looking for articles on pH, potential renal acid loads, bone health, muscle, growth hormone, back pain, vitamin D and chemotherapy. Many books written in the lay literature on the alkaline diet were also reviewed and evaluated in light of the published medical literature. There may be some value in considering an alkaline diet in reducing morbidity and mortality from chronic diseases and further studies are warranted in this area of medicine.

Diet-induced metabolic acidosis

The modern Western-type diet is deficient in fruits and vegetables and contains excessive animal products, generating the accumulation of non-metabolizable anions and a lifespan state of overlooked metabolic acidosis, whose magnitude increases progressively with aging due to the physiological decline in kidney function. In response to this state of diet-derived metabolic acidosis, the kidney implements compensating mechanisms aimed to restore the acid-base balance, such as the removal of the non-metabolizable anions, the conservation of citrate, and the enhancement of kidney ammoniagenesis and urinary excretion of ammonium ions. These adaptive processes lower the urine pH and induce an extensive change in urine composition, including hypocitraturia, hypercalciuria, and nitrogen and phosphate wasting. Low urine pH predisposes to uric acid stone formation. Hypocitraturia and hypercalciuria are risk factors for calcium stone disease. Even a very mild degree of metabolic acidosis induces skeletal muscle resistance to the insulin action and dietary acid load may be an important variable in predicting the metabolic abnormalities and the cardiovascular risk of the general population, the overweight and obese persons, and other patient populations including diabetes and chronic kidney failure. High dietary acid load is more likely to result in diabetes and systemic hypertension and may increase the cardiovascular risk. Results of recent observational studies confirm an association between insulin resistance and metabolic acidosis markers, including low serum bicarbonate, high serum anion gap, hypocitraturia, and low urine pH.

The use of a commercial vegetable juice as a practical means to increase vegetable intake: a randomized controlled trial

BACKGROUND

Recommendations for daily dietary vegetable intake were increased in the 2005 USDA Dietary Guidelines as consumption of a diet rich in vegetables has been associated with lower risk of certain chronic health disorders including cardiovascular disease. However, vegetable consumption in the United States has declined over the past decade; consequently, the gap between dietary recommendations and vegetable intake is widening. The primary aim of this study is to determine if drinking vegetable juice is a practical way to help meet daily dietary recommendations for vegetable intake consistent with the 2005 Dietary Guidelines and the Dietary Approaches to Stop Hypertension (DASH) diet. The secondary aim is to assess the effect of a vegetable juice on measures of cardiovascular health.

METHODS

We conducted a 12-week, randomized, controlled, parallel-arm study consisting of 3 groups of free-living, healthy volunteers who participated in study visits at the Ragle Human Nutrition Research Center at the University of California, Davis. All subjects received education on the DASH diet and 0, 8 or 16 fluid ounces of vegetable juice daily. Assessments were completed of daily vegetable servings before and after incorporation of vegetable juice and cardiovascular health parameters including blood pressure.

RESULTS

Without the juice, vegetable intake in all groups was lower than the 2005 Dietary Guidelines and DASH diet recommendations. The consumption of the vegetable juice helped participants reach recommended intake. In general, parameters associated with cardiovascular health did not change over time. However, in the vegetable juice intervention groups, subjects who were pre-hypertensive at the start of the study showed a significant decrease in blood pressure during the 12-week intervention period.

CONCLUSION

Including 1-2 cups of vegetable juice daily was an effective and acceptable way for healthy adults to close the dietary vegetable gap. Increase in daily vegetable intake was associated with a reduction in blood pressure in subjects who were pre-hypertensive at the start of the trial.

TRIAL REGISTRATION

Clinicaltrials.gov NCT01161706.

Chronic inflammation in obesity and the metabolic syndrome

The increasing incidence of obesity and the metabolic syndrome is disturbing. The activation of inflammatory pathways, used normally as host defence, reminds the seriousness of this condition. There is probably more than one cause for activation of inflammation. Apparently, metabolic overload evokes stress reactions, such as oxidative, inflammatory, organelle and cell hypertrophy, generating vicious cycles. Adipocyte hypertrophy, through physical reasons, facilitates cell rupture, what will evoke an inflammatory reaction. Inability of adipose tissue development to engulf incoming fat leads to deposition in other organs, mainly in the liver, with consequences on insulin resistance. The oxidative stress which accompanies feeding, particularly when there is excessive ingestion of fat and/or other macronutrients without concomitant ingestion of antioxidant-rich foods/beverages, may contribute to inflammation attributed to obesity. Moreover, data on the interaction of microbiota with food and obesity brought new hypothesis for the obesity/fat diet relationship with inflammation. Beyond these, other phenomena, for instance psychological and/or circadian rhythm disturbances, may likewise contribute to oxidative/inflammatory status. The difficulty in the management of obesity/metabolic syndrome is linked to their multifactorial nature where environmental, genetic and psychosocial factors interact through complex networks.

The Medical Management of Urolithiasis

Urolithiasis is increasing in prevalence and causes substantial morbidity and economic burden. Aside from “acute” stone episodes, urolithiasis should be regarded as a systemic disorder and investigated fully. Practical guidance is given for the medical investigation, diagnosis and treatment of urolithiasis. A single episode of urolithiasis should prompt a review of potential risk factors for recurrent disease and appropriate baseline investigations should be performed. Further biochemical tests may then be directed appropriately and allow individualised advice and treatment to be given to the patient with urolithiasis.

Partial substitution of sodium with potassium in white bread: feasibility and bioavailability

A high sodium intake, to which bread makes a major contribution, and a low potassium intake are believed to be important factors in the promotion of cardiovascular disease. Our aims was to determine to what extent salts of potassium could substitute sodium chloride and potassium-rich soya flour could replace wheat flour without detrimental effect on acceptability, and to measure the bioavailability of a potassium salt added to bread. A single-blind organoleptic evaluation was carried out on eight different potassium-enriched breads by 41 panellists. Thereafter, six volunteers consumed standard or potassium-chloride-fortified bread in an 11-day single-blind cross-over feeding trial to determine the bioavailability of the supplemental potassium. Two breads in which 30% of the sodium was replaced by potassium salts, and bread in which 10% of wheat flour was replaced with soy flour, had acceptability scores similar to the standard bread. In the metabolic study a supplement of 22 mmol/day potassium chloride incorporated into the bread was found to be wholly bioavailable. A substantial reduction in sodium and an increase in potassium intake could be achieved by substituting potassium salts for sodium chloride in bread.

Variations in the WNK1 gene modulates the effect of dietary intake of sodium and potassium on blood pressure determination

WNK lysine-deficient protein kinase 1 (WNK1) is a member of the WNK family of serine/threonine kinases with no lysine (K), and these kinases have been implicated as important modulators of salt homeostasis in the kidney. It is well known that high dietary sodium and low dietary potassium have been implicated in the etiology of increased blood pressure. However, the blood pressure response to dietary sodium and potassium intake varies considerably among individuals. In this study, we have detected that the haplotypes of the WNK1 gene are associated with blood pressure variations in the general Japanese population. In addition, we investigated the interactions between the haplotypes of the WNK1 gene and dietary sodium and potassium intake for determining inter-individual variations in blood pressure. Our data support the hypothesis that part of the variation in blood pressure response to dietary sodium and potassium intake among individuals can be explained by variations in the WNK1 gene.

Diet to reduce mild hyperoxaluria in patients with idiopathic calcium oxalate stone formation: a pilot study

OBJECTIVES

To assess whether a normal-calcium, low-animal protein, low-salt diet is effective in reducing hyperoxaluria in idiopathic calcium oxalate nephrolithiasis compared with a traditional low-oxalate diet, routinely recommended by clinicians

METHODS

We treated 56 patients with idiopathic calcium oxalate stone formation who presented with mild hyperoxaluria (>40 mg/d) while consuming a free diet with a normal-calcium, low-animal protein, low-salt diet for a 3-month period. We compared the results obtained with this diet with those of a historical control group of 20 hyperoxaluric patients treated in the traditional way with a low-oxalate diet

RESULTS

After 3 months of therapy, the mean oxaluria level had decreased from 50.2 to 35.5 mg/d with the normal-calcium, low-animal protein, low-salt diet and from 45.9 to 40.2 mg/d with the traditional diet (adjusted difference between post-treatment mean value -7.3 mg/d, 95% confidence interval -12.3 to -2.2, P = .005)

CONCLUSIONS

The results suggest that a normal-calcium, low-animal protein, low-salt diet can reduce oxalate excretion in hyperoxaluric patients. This should encourage the undertaking of a randomized-control study to confer more solid evidence in support of our findings.

Beneficial effects of potassium on human health

Until recently, humans consumed a diet high in potassium. However, with the increasing consumption of processed food, which has potassium removed, combined with a reduction in the consumption of fruits and vegetables, there has been a large decrease in potassium intake which now, in most developed countries, averages around 70 mmol day-1, i.e. only one third of our evolutionary intake. Much evidence shows that increasing potassium intake has beneficial effects on human health. Epidemiological and clinical studies show that a high-potassium diet lowers blood pressure in individuals with both raised blood pressure and average population blood pressure. Prospective cohort studies and outcome trials show that increasing potassium intake reduces cardiovascular disease mortality. This is mainly attributable to the blood pressure-lowering effect and may also be partially because of the direct effects of potassium on the cardiovascular system. A high-potassium diet may also prevent or at least slow the progression of renal disease. An increased potassium intake lowers urinary calcium excretion and plays an important role in the management of hypercalciuria and kidney stones and is likely to decrease the risk of osteoporosis. Low serum potassium is strongly related to glucose intolerance, and increasing potassium intake may prevent the development of diabetes that occurs with prolonged treatment with thiazide diuretics. Reduced serum potassium increases the risk of lethal ventricular arrhythmias in patients with ischaemic heart disease, heart failure and left ventricular hypertrophy, and increasing potassium intake may prevent this. The best way to increase potassium intake is to increase the consumption of fruits and vegetables.

Adverse effects of sodium chloride on bone in the aging human population resulting from habitual consumption of typical American diets

A typical American diet contains amounts of sodium chloride far above evolutionary norms and potassium far below those norms. It also contains larger amounts of foods that are metabolized to noncarbonic acids than to organic bases. At baseline, in a steady state, diets that contain substantial sodium chloride and diets that are net acid producing each independently induce and sustain increased acidity of body fluid. With increasing age, the kidney's ability to excrete daily net acid loads declines, invoking homeostatically increased utilization of base stores (bone, skeletal muscle) on a daily basis to mitigate the otherwise increasing baseline metabolic acidosis, which results in increased calciuria and net losses of body calcium. Those effects of net acid production and its attendant increased body fluid acidity may contribute to development of osteoporosis and renal stones, loss of muscle mass, and age-related renal insufficiency. The inverted ratio of potassium to sodium in the diet compared with preagricultural diets affects cardiovascular function adversely and contributes to hypertension and stroke. The diet can return to its evolutionary norms of net base production inducing low-grade metabolic alkalosis and a high potassium-to-sodium ratio by 1) greatly reducing content of energy-dense nutrient-poor foods and potassium-poor acid-producing cereal grains, which would entail increasing consumption of potassium-rich net base-producing fruits and vegetables for maintenance of energy balance, and 2) greatly reducing sodium chloride consumption. Increasingly, evidence supports the health benefits of reestablishing evolutionary norms of dietary net base loads and high potassium and low sodium chloride loads. We focus here on the American diet's potential effects on bone through its superphysiologic content of sodium chloride.

The effect of a dietary supplement of potassium chloride or potassium citrate on blood pressure in predominantly normotensive volunteers

Blood pressure (BP) shows a continuous relationship with the risk of CVD. There is substantial evidence that dietary potassium exerts an anti-pressor effect. Most clinical trials have used KCl. However, the chloride ion may have a pressor effect and in foods potassium is associated with organic anions. In a double-blind randomized placebo-controlled trial we explored the effect on BP of two salts of potassium, KCl and potassium citrate (K-cit), in predominantly young healthy normotensive volunteers. The primary outcome was the change in mean arterial pressure as measured in a clinic setting. After 6 weeks of supplementation, compared with the placebo group (n 31), 30 mmol K-cit/d (n 28) changed mean arterial pressure by -5.22 mmHg (95% CI -8.85, -4.53) which did not differ significantly from that induced by KCl (n 26), -4.70 mmHg (-6.56, -2.84). The changes in systolic and diastolic BP were -6.69 (95% CI -8.85, -4.43) and -4.26 (95% CI -6.31, -2.21) mmHg with K-cit and -5.24 (95% CI -7.43, -3.06) and -4.30 (95% CI -6.39, -2.20) mmHg with KCl, and did not differ significantly between the two treatments. Changes in BP were not related to baseline urinary electrolytes. A greater treatment-related effect was observed in those with higher systolic BP. Increasing dietary potassium could therefore have a significant impact on the progressive rise in BP in the entire population.