Dietary sources and correlates of sodium and potassium intakes in the French general population

The effect of dietary sodium and fructose intake on urine and serum parameters of stone formation in a pediatric mouse model: a pilot study

PURPOSE

Dietary factors have a role in stone disease in adults but little is known about the relationship in children. We tested whether diet could alter urine and serum parameters in a pediatric mouse model.

MATERIALS AND METHODS

We randomized 30 female BALB/c mice at age 3 weeks to mouse chow, a complex carbohydrate Western diet or a high fructose, high sodium Western diet. Body weight was measured twice weekly. Urine was periodically collected and mice were sacrificed on day 30. Samples were pooled to analyze serum and urine electrolyte factors.

RESULTS

There was no significant difference in body weights among the groups at any time or in kidney weight at sacrifice (each p >0.15). There was no observable increase in urine stone forming analytes across the arms except uric acid, which tended to be higher in the Western diet and high fructose, high sodium Western diet groups. There was a substantial decrease in urinary stone inhibitors (magnesium and citrate), a decrease in urinary potassium and an increase in serum calcium in the 2 Western diet groups.

CONCLUSIONS

This pilot study suggests that consuming a Western diet, especially one composed of high fructose and sodium, may alter parameters that predispose to stone formation in children by decreasing stone inhibitors. Results require validation in larger studies and ultimately in humans.

Food pattern modeling shows that the 2010 Dietary Guidelines for sodium and potassium cannot be met simultaneously

The 2010 US Dietary Guidelines recommended limiting intake of sodium to 1500 mg/d for people older than 50 years, African Americans, and those suffering from chronic disease. The guidelines recommended that all other people consume less than 2300 mg sodium and 4700 mg of potassium per day. The theoretical feasibility of meeting the sodium and potassium guidelines while simultaneously maintaining nutritional adequacy of the diet was tested using food pattern modeling based on linear programming. Dietary data from the National Health and Nutrition Examination Survey 2001-2002 were used to create optimized food patterns for 6 age-sex groups. Linear programming models determined the boundary conditions for the potassium and sodium content of the modeled food patterns that would also be compatible with other nutrient goals. Linear programming models also sought to determine the amounts of sodium and potassium that both would be consistent with the ratio of Na to K of 0.49 and would cause the least deviation from the existing food habits. The 6 sets of food patterns were created before and after an across-the-board 10% reduction in sodium content of all foods in the Food and Nutrition Database for Dietary Studies. Modeling analyses showed that the 2010 Dietary Guidelines for sodium were incompatible with potassium guidelines and with nutritionally adequate diets, even after reducing the sodium content of all US foods by 10%. Feasibility studies should precede or accompany the issuing of dietary guidelines to the public.

The effect of NaCl substitution with KCl on Akawi cheese: chemical composition, proteolysis, angiotensin-converting enzyme-inhibitory activity, probiotic survival, texture profile, and sensory properties

The effect of partial substitution of NaCl with KCl on Akawi cheese with probiotic bacteria was investigated during 30 d of storage at 4 °C. Chemical composition, the survival of probiotic and lactic acid bacteria, proteolytic activity, and texture profile analysis were analyzed and sensory analysis was carried out to determine the effects of substitution. No significant differences were observed in moisture, protein, fat, and ash contents among the experimental Akawi cheeses at the same storage period. Significant differences were observed in water-soluble nitrogen and phosphotungstic-soluble nitrogen between experimental cheeses at the same of storage period. No significant difference was observed in the growth of Lactobacillus delbrueckii ssp. bulgaricus between experimental cheeses at the same storage period. However, the growth of Streptococcus thermophilus, Lactobacillus casei, and Lactobacillus acidophilus was significantly affected among experimental cheeses. A significant difference was observed in soluble Ca among experimental cheeses at the same storage period. In general, no significant differences existed in hardness and adhesiveness among experimental cheeses at the same storage period. No significant differences existed in sensory attributes, including creaminess, bitterness, saltiness, sour-acid, and vinegar taste among experimental Akawi cheeses at the same storage period.

Salt content impacts food preferences and intake among children

Decreasing dietary sodium intake, which can be achieved by reducing salt content in food, is recommended. Salt contributes to the taste of foods and makes them more enjoyable. Whether a food is liked or disliked is an important determinant of food intake, especially among children. However, the role of salt in children's food acceptance has received little attention. The impact of salt content on children's hedonic rating and intake of two foods was investigated in children. Using a within-subject crossover design, we recruited 75 children (8–11 years) to participate in five lunches in their school cafeteria. The target foods were green beans and pasta. The added salt content was 0, 0.6 or 1.2 g/100 g. The children's intake (g) of all lunch items was measured. The children provided their hedonic rating of the food, a preference ranking and a saltiness ranking in the laboratory. Children could rank the foods according to salt content, and they preferred the two saltier options. A food-specific effect of salt content on intake was observed. Compared to the intermediate level (0.6 g salt/100 g), not adding salt decreased green bean intake (−21%; p = 0.002), and increasing the salt content increased pasta intake (+24%; p<0.0001). Structural Equation Modeling was used to model the relative weights of the determinants of intake. It showed that the primary driver of food intake was the child's hunger; the second most important factor was the child's hedonic rating of the food, regardless of its salt content, and the last factor was the child's preference for the particular salt content of the food. In conclusion, salt content has a positive and food-specific effect on intake; it impacted food preferences and intake differently in children. Taking into account children's preferences for salt instead of their intake may lead to excessive added salt.

Association between 24-hour urine sodium and potassium excretion and diet quality in six-year-old children: a cross sectional study

Background

Limited data is available on sodium (Na) and potassium (K) intake in young children estimated by 24 hour (24h) excretion in urine. The aim was to assess 24h urinary excretion of Na and K in six-year-old children and its relationship with diet quality.

Methods

The study population was a subsample of a national dietary survey, including six-year-old children living in the greater Reykjavik area (n=76). Three day weighed food records were used to estimate diet quality. Diet quality was defined as adherence to the Icelandic food based dietary guidelines. Na and K excretion was analyzed from 24h urine collections. PABA check was used to validate completeness of urine collections. The associations between Na and K excretion and diet quality were estimated by linear regression, adjusting for gender and energy intake.

Results

Valid urine collections and diet registrations were provided by 58 children. Na and K excretion was, mean (SD), 1.64 (0.54) g Na/24h (approx. 4.1 g salt/24h) and 1.22 (0.43) g K/24h. In covariate adjusted models Na excretion decreased by 0.16 g Na/24h (95% CI: 0.31, 0.06) per 1-unit increase in diet quality score (score range: 1–4) while K excretion was increased by 0.18 g K/24h (95% CI: 0.06, 0.29).

Conclusions

Na intake, estimated by 24h urinary excretion was on average higher than recommended. Increased diet quality was associated with lower Na excretion and higher K excretion in six-year-old children.

Reducing the sodium-potassium ratio in the US diet: a challenge for public health

BACKGROUND

The 2010 Dietary Guidelines emphasized that dietary sodium should be limited to 2300 mg/d, with a lower limit of 1500 mg/d for adults aged >50 y, non-Hispanic blacks, and those with diabetes, hypertension, or chronic kidney disease. The potassium goal remained at 4700 mg/d.

OBJECTIVE

The objective was to identify subpopulations for whom the 1500- or 2300-mg Na/d goals applied and to examine the joint sodium and potassium intakes for these persons.

DESIGN

The analyses were based on NHANES 2003-2008 data for 12,038 adult men and women aged ≥20 y. Persons aged >50 y, non-Hispanic blacks, and persons with hypertension, diabetes, and chronic kidney disease were identified. Mean sodium, potassium, and energy intakes were obtained from 2 nonconsecutive 24-h dietary recalls. Historical analyses of the sodium-potassium ratios in the American diet were based on NHANES 1971-2006.

RESULTS

Among persons recommended to consume <2300 mg Na/d, <0.12% jointly met the sodium and potassium guidelines. In the 1500-mg/d group, the guidelines were jointly met by <0.015%. Based on Dietary Guidelines, the corresponding dietary sodium-potassium ratio was either 0.49 (2300/4700) or 0.32 (1500/4700). Historical analyses of NHANES data by age-sex groups from 1971 to 2006 showed that sodium-potassium ratios were never <0.83.

CONCLUSIONS

Joint dietary guidelines for sodium and potassium, intended for most American adults, are currently being met by ≤0.015% of the population. Extraordinary efforts will be needed to meet the recommendations of the Dietary Guidelines.

The impact of NaCl substitution with KCl on proteinase activities cell-free extract and cell-free supernatant at different pH levels and salt concentrations: Lactobacillus delbrueckii ssp. bulgaricus and Streptococcus thermophilus

The effect of NaCl substitution with KCl at different pH levels (6.0, 5.5, and 5.0) and salt concentrations on proteinase activities of cell-free and supernatant of Lactobacillus delbrueckii ssp. bulgaricus 11824 (L. bulgaricus) and Streptococcus thermophilus MS (ST) was investigated. MRS broths were separately mixed with 4 salt treatments (NaCl only, 1NaCl:1KCl, 1NaCl:3KCl, and KCl only) at 2 different concentrations (5% and 10%) and incubated at 37 °C for 22 h. The cell pellets were used to prepare proteinase of cell-free extract and the cell-free supernatants were used as source of extracellular proteinases. The proteolytic activities and protein contents of both fractions were determined. The supernatants after incubation of both fractions with 3 milk caseins (α-, β-, κ-casein) were subjected to angiotensin-converting-enzyme inhibitory (ACE-inhibitory) activity and proteolytic activity by ortho-phthalaldehyde (OPA) method. Significant differences were observed in ACE-inhibitory activities and proteolytic (OPA) between salt treatments of cell-free extract and cell-free supernatant of L. bulgaricus and S. thermophilus at same salt concentration and same pH level. There was a significant effect of pH level and salt treatments interaction on ACE-inhibitory activity, OPA activity and azocasein activity.

PRACTICAL APPLICATION

To reduce sodium concentration in cheese by substituting of NaCl with KCl, it was important to study the effect on starter culture proteinases which play a vital role in ripening and texture profile of cheese.

Food sources and correlates of sodium and potassium intakes in Flemish pre-school children

Objective

The aim of the present study was to investigate dietary sources of Na and K intakes among Flemish pre-school children using multiple linear regression analyses.

Design

Three-day estimated diet records were used to assess dietary intakes. The contribution to Na and K intakes of fifty-seven food groups was computed by summing the amount provided by the food group for all individuals divided by the total intake for all individuals.

Setting

A random cluster sampling design at the level of schools, stratified by province and age, was used.

Subjects

A representative sample of 696 Flemish pre-school children aged 2·5–6·5 years was recruited.

Results

Mean Na intake was above and mean K intake was largely below the recommendation for children. Bread (22 %) and soup (13 %) were main contributors to Na intake followed by cold meat cuts and other meat products (12 % and 11 %, respectively). Sugared milk drinks, fried potatoes, milk and fruit juices were the main K sources (13 %, 12 %, 11 % and 11 %, respectively). Although Na and K intakes were positively correlated, several food categories showed Na:K intake ratio well above one (water, cheeses, soup, butter/margarine, fast foods and light beverages) whereas others presented a ratio well below one (oil & fat, fruits & juices, potatoes, vegetables and hot beverages).

Conclusions

Flemish pre-school children had too high Na and too low K intakes. The finding that main dietary sources of Na and K are clearly different indicates the feasibility of simultaneously decreasing Na and increasing K intake among children.

24 h-Sodium excretion and hydration status in children and adolescents--results of the DONALD Study

BACKGROUND & AIMS

To describe actual data on intake, sources, age and time trends of urinary sodium excretion and to analyze the potential association between urinary sodium excretion and hydration status respective beverage consumption in a sample of healthy German children and adolescents.

METHODS

Data of 1575 24 h-urine samples and weighed dietary records of 499 children (249 boys) aged 4-18 years of the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study collected in 2003-2009 were analyzed using linear mixed effects regression models. Free water reserve (FWR, measured urine volume (ml/24 h) minus the obligatory urine volume (ml/24 h)) was used as a marker for hydration status.

RESULTS

Urinary sodium excretion was between 1.4 g/day and 3.2 g/day, showing a positive age trend but remained stable during the study period. In girls, there was a significant positive association between salt excretion and FWR (p = 0.04). Per g/MJ urinary sodium excretion, beverage intake increased by 0.05 g/MJ (boys) or 0.08 g/MJ (girls).

CONCLUSION

Hydration status was not affected by salt intake in this sample of healthy children and adolescents in a western life style, due to a compensatory increase in beverage consumption.

Canadians continue to consume too much sodium and not enough potassium

OBJECTIVES

Excessive sodium (Na) intakes and insufficient potassium (K) intakes are known contributors to hypertension. In July 2010, the Health Canada-led multi-stakeholder Sodium Working Group issued recommendations to lower Na intakes of Canadians. Baseline data and ongoing monitoring are needed.

METHODS

Na and K content based on recently analyzed food composite samples from the Canadian marketplace were matched with over 35,000 dietary recalls from the Canadian Community Health Survey (CCHS 2.2). The distributions of usual intakes for Na and K were constructed using SIDE software and estimates by age and sex for the 5th, 10th, 25th, mean, median, 75th, 90th and 95th percentiles were determined.

RESULTS

Based on recent analyses of Canadian foods, the majority of Canadians exceeded the Tolerable Upper Intake Level (UL) for Na for their age and sex group, including infants, children, adolescents and adults. In sharp contrast, few had Adequate Intakes (AI) of K.

CONCLUSION

Canadians of all ages need to decrease Na intakes below the UL. At the same time, increased consumption of dairy products, fruits and vegetables must be promoted to increase K intakes to current recommendations. Both dietary interventions are required to help lower hypertension in the Canadian population. We provide the first report based on direct analysts of Canadian foods, confirming the high Na and low K intakes of the Canadian population. With its annual sampling program of foods commonly consumed in Canada, the Total Diet Study provides an important sentinel system for monitoring these dietary risk factors for hypertension.

Sources of sodium in Australian children's diets and the effect of the application of sodium targets to food products to reduce sodium intake

The average reported dietary Na intake of children in Australia is high: 2694 mg/d (9-13 years). No data exist describing food sources of Na in Australian children's diets and potential impact of Na reduction targets for processed foods. The aim of the present study was to determine sources of dietary Na in a nationally representative sample of Australian children aged 2-16 years and to assess the impact of application of the UK Food Standards Agency (FSA) Na reduction targets on Na intake. Na intake and use of discretionary salt (note: conversion of salt to Na, 1 g of NaCl (salt) = 390 mg Na) were assessed from 24-h dietary recall in 4487 children participating in the Australian 2007 Children's Nutrition and Physical Activity Survey. Greatest contributors to Na intake across all ages were cereals and cereal-based products/dishes (43%), including bread (13%) and breakfast cereals (4%). Other moderate sources were meat, poultry products (16%), including processed meats (8%) and sausages (3%); milk products/dishes (11%) and savoury sauces and condiments (7%). Between 37 and 42% reported that the person who prepares their meal adds salt when cooking and between 11 and 39% added salt at the table. Those over the age of 9 years were more likely to report adding salt at the table (χ2 199·5, df 6, P < 0·001). Attainment of the UK FSA Na reduction targets, within the present food supply, would result in a 20% reduction in daily Na intake in children aged 2-16 years. Incremental reductions of this magnitude over a period of years could significantly reduce the Na intake of this group and further reductions could be achieved by reducing discretionary salt use.