Consumption and sources of dietary salt in family members in Beijing

Impact of dietary sodium restriction on falls among middle-aged and older adults: Results of an 8-year longitudinal study

AIM

This study aimed to understand the relationship between dietary sodium restriction (DSR) and falling experiences in middle-aged and older adults.

METHODS

The 8-year follow-up data from the Taiwan Longitudinal Study on Aging, covering 5131 individuals aged ≥50 years, were analyzed using random-effects panel logit models. Participants were asked to indicate whether they were told by a physician to reduce or avoid sodium intake from food and whether they had had fall experiences during the past year. We modelled falling experiences as a function of DSR (independent variable), involuntary body weight loss and walking difficulty (mediators), and chronic diseases (moderator), adjusting for individual-level characteristics.

RESULTS

Individuals with DSR were at a higher risk of falls compared with those with no DSR (adjusted odds ratio [AOR] = 1.30, 95% confidence interval [CI] = 1.11-1.53). This effect was more prevalent in individuals with a history of stroke (AOR = 1.85, 95% CI = 1.19-2.87). Those told to reduce sodium intake by a physician were likely to lose weight involuntarily (AOR = 1.20, 95% CI = 1.05-1.36) and had difficulty walking up two or three flights of stairs alone (AOR = 2.38, 95% CI = 1.73-3.27), which mediated the effect of DSR on increased fall risk (AOR = 1.15, 95% CI = 0.95-1.38). We found a temporal effect: participant reactions to short- and mid-term DSR were significant.

CONCLUSIONS

DSR was associated with a greater likelihood of falls among middle-aged and older adults, particularly those with a history of stroke. Geriatr Gerontol Int 2024; 24: 292-299.

Association between home meal preparers and salt intake in haemodialysis patients: a cross-sectional study

OBJECTIVES

This study aimed to examine the association between home meal preparer and salt intake among haemodialysis patients, including daily dietary status. We hypothesised that salt intake is higher among individuals who rely on meal preparation from others than those who prepare meals by themselves.

DESIGN

Cross-sectional study.

SETTING

Two medical facilities in Fukushima Prefecture, Japan.

PARTICIPANTS

237 haemodialysis outpatients who visited one of the medical facilities between February 2020 and August 2021 and were diagnosed with anuria, defined as urination of <100 mL/day, were the potential participants of the present study. Finally, 181 participants (131 male and 50 female) were included in the analysis.

OUTCOME MEASURE

Salt intake amount was calculated from the results of predialysis and postdialysis blood draws, using Watson's formula based on predialysis weight, predialysis serum sodium level, postdialysis weight and serum sodium level at the end of dialysis.

RESULTS

Salt intake was significantly higher in participants who relied on meal preparation from others ('relying on others') than those who prepared meals by themselves ('self-prepared') (B=1.359; 95% CI: 0.495 to 2.222). No statistical difference was found between individuals who ate out or ate takeout ('outsourcing') and those who prepared their own meals ('self-prepared'). These results were robust after adjustment for confounding factors.

CONCLUSIONS

The present study revealed an association between self-preparation of meals at home and reduced salt intake among dialysis patients. Our findings suggest that whoever is the home meal preparer is possibly a social determinant of salt intake. To improve the prognosis of haemodialysis patients, actively reaching out to the family and assessing their social environment, such as identifying the home meal preparer and, if the patient relies on others for meal preparation, conducting nutritional/dietary guidance for that person, are effective in enhancing salt reduction.

Awareness and Use of Low-Sodium Salt Substitutes and Its Impact on 24-h Urinary Sodium and Potassium Excretion in China-A Cross-Sectional Study

The use of low-sodium salt substitute (LSSS) has the potential to reduce sodium and increase potassium intake. LSSS has been available in the Chinese market for years. However, its real-world use and impact on sodium/potassium intake is unclear. Baseline data of 4000 adult individuals who participated in three similarly designed randomized controlled trials were pooled together for this analysis. Self-reported awareness and use of LSSS were collected using a standardized questionnaire, and the participants' 24-h urinary sodium and potassium excretion was used to estimate their dietary intake. Mixed-effects models were developed to assess the relationship between LSSS and 24-h urinary sodium and potassium excretion. 32.0% of the participants reported awareness of LSSS and 11.7% reported its current use. After adjusting for location, sex, age, and education, compared with the group of participants unaware of LSSS, participants who were aware of but not using LSSS and those who were using LSSS had a lower 24-h urinary sodium excretion by -356.1 (95% CI: -503.9, -205.9) mg/d and -490.6 (95% CI: -679.2, -293.7) mg/d, respectively (p < 0.001). No significant difference was found for 24-h urinary potassium excretion or sodium-to-potassium ratio among the three groups (p > 0.05). In conclusion, the findings of low usage of LSSS and the reduced urinary sodium excretion associated with the awareness and use of LSSS provide further support for the prometon of LSSS as a key salt reduction strategy in China.

Dietary Factors, Dietary Patterns, and Cardiovascular Disease Risk in Representative Japanese Cohorts: NIPPON DATA80/90

Diet is one of the most important factors affecting healthy life expectancy through the onset of cardiovascular disease (CVD) risk as well as various chronic diseases. Because dietary habits and disease structure differ depending on the country, region, and/or race, evidence from each population is required. NIPPON DATA80/90 is a long-term cohort study of a representative Japanese population that participated in national nutrition surveys. Among the many findings of this cohort study, a dietary pattern with higher intake of fruits, vegetables, fish (n-3 polyunsaturated fatty acids), and dietary fiber and lower intake of salt as well as sodium-to-potassium ratio was found to be associated with a lower risk of CVD mortality. The results from our cohort study would be useful for effectively preventing CVD. This article reviews the published studies from the NIPPON DATA80/90 to highlight the significant findings that may be used to develop risk prevention strategies for CVD.

High Dietary Sodium, Measured Using Spot Urine Samples, is Associated with Higher Blood Pressure among Young Adults in Haiti

Background

Hypertension (HTN) is the leading cardiovascular disease (CVD) risk factor in Haiti and is likely driven by poverty-related social and dietary factors. Salt consumption in Haiti is hypothesized to be high but has never been rigorously quantified.

Methods

We used spot urine samples from a subset of participants in the population-based Haiti Cardiovascular Disease Cohort to estimate population mean daily sodium intake. We compared three previously validated formulas for estimating dietary sodium intake using urine sodium, urine creatinine, age, sex, height, and weight. We explored the association between dietary sodium intake and blood pressure, stratified by age group.

Results

A total of 1,240 participants had spot urine samples. Median age was 38 years (range 18-93), and 48% were female. The mean dietary sodium intake was 3.5-5.0 g/day across the three estimation methods, with 94.2%-97.9% of participants consuming above the World Health Organization (WHO) recommended maximum of 2 g/day of sodium. Among young adults aged 18-29, increasing salt intake from the lowest quartile of consumption (<3.73 g/day) to the highest quartile (>5.88 g/day) was associated with a mean 8.71 mmHg higher systolic blood pressure (SBP) (95% confidence interval: 3.35, 14.07; p = 0.001). An association was not seen in older age groups. Among participants under age 40, those with SBP ≥120 mmHg consumed 0.5 g/day more sodium than those with SBP <120 mmHg (95% confidence interval: 0.08, 0.69; p = 0.012).

Conclusions

Nine out of 10 Haitian adults in our study population consumed more than the WHO recommended maximum for daily sodium intake. In young adults, higher sodium consumption was associated with higher SBP. This represents an inflection point for increased HTN risk early in the life course and points to dietary salt intake as a potential modifiable risk factor for primordial and primary CVD prevention in young adults.

Genetic and Biological Effects of SLC12A3, a Sodium-Chloride Cotransporter, in Gitelman Syndrome and Diabetic Kidney Disease

The SLC12A3 (Solute carrier family 12 member 3) gene encodes a sodium-chloride cotransporter and mediates Na+ and Cl− reabsorption in the distal convoluted tubule of kidneys. An experimental study has previously showed that with knockdown of zebrafish ortholog, slc12a3 led to structural abnormality of kidney pronephric distal duct at 1-cell stage, suggesting that SLC12A3 may have genetic effects in renal disorders. Many clinical reports have demonstrated that the function-loss mutations in the SLC12A3 gene, mainly including Thr60Met, Asp486Asn, Gly741Arg, Leu859Pro, Arg861Cys, Arg913Gln, Arg928Cys and Cys994Tyr, play the pathogenic effects in Gitelman syndrome. This kidney disease is inherited as an autosomal recessive trait. In addition, several population genetic association studies have indicated that the single nucleotide variant Arg913Gln in the SLC12A3 gene is associated with diabetic kidney disease in type 2 diabetes subjects. In this review, we first summarized bioinformatics of the SLC12A3 gene and its genetic variation. We then described the different genetic and biological effects of SLC12A3 in Gitelman syndrome and diabetic kidney disease. We also discussed about further genetic and biological analyses of SLC12A3 as pharmacokinetic targets of diuretics.

Association of Salt-Reduction Knowledge and Behaviors and Salt Intake in Chinese Population

Objective

Excessive salt intake is causally associated with an increased risk of cardiovascular disease. Salt-reduction strategies have been rapidly deployed across China since 2017. This study aimed to investigate the association of salt-reduction knowledge and behaviors and salt intake in Chinese population.

Study Design

This study was a national cross-sectional study in China.

Methods

This cross-sectional study was based on data collected during a Chinese adult chronic disease and nutrition surveillance program in 2018 with 7,665 study participants. Salt intake was assessed by calculating 24 h urine sodium from morning urine samples. Logistic regression and mean impact value (MIV) based on the back propagation (BP) artificial neural network were used to screen the potential influencing factors.

Results

A total of 7,665 participants were included in the analysis, with an average age of 54.64 ± 13.26 years, and with men accounting for 42.6%. Only 19.3% of the participants were aware of the Chinese Dietary Guidelines, and only 7.3% of them could accurately identify the level of salt intake recommended in the Chinese Dietary Guidelines. Approximately 41% of the participants adopted salt-reduction behaviors, among whom the number of participants who used less salt when cooking was the highest, and the number of participants who used low sodium salt was the lowest. In the logistic regression, only "No extra salt was added at the table" group showed the effect of salt-reduction, the odds ratio (OR) being 0.78 (95% confidence interval [CI]: 0.64-0.95). The MIV result based on the BP neural network showed that the most important salt-reduction behavior was using less salt when cooking, while reducing eating-out behavior and using salt-limiting tools were the least important.

Conclusion

The research shows that the popularization of salt-reduction knowledge and behaviors can reduce the population's salt intake. However, there is still considerable scope for promoting salt-reduction knowledge and behaviors, while the promotion of salt-reduction tools and low-sodium salt still needs to be strengthened.

Factors affecting reductions in dietary salt consumption in people of Chinese descent: An integrative review

Aims

To identify and synthesize the evidence on the perceptions of the health effects of dietary salt consumption and barriers to sustaining a salt‐reduced diet for hypertension in Chinese people.

Design

A systematic integrated review integrating quantitative and qualitative studies using the PRISMA guidelines.

Data sources

Three databases, MEDLINE, PubMed and CINAHL, were systematically searched for articles published between January 2001 and July 2020.

Review methods

The quality of the included studies was appraised using the Joanna Briggs Institute's critical appraisal tools for cross‐sectional and qualitative studies. Descriptive analysis and constant comparison methods were used to analyse the extracted data.

Results

Fourteen studies met the inclusion criteria. The synthesized results identified that (i) adequate salt‐related health education had a positive influence on dietary behaviour modifications, (ii) the level of educational exposure to the health benefits of salt reduction influenced Chinese people's perceptions of the health impact associated with high salt intake, (iii) the complexity of salt measurement was a barrier to salt reduction, (iv) salt reduction is a challenge to Chinese food culture, and (v) Chinese migrants may experience linguistic and cultural challenges when they seek appropriate dietary education and advice for hypertension management in their host countries.

Conclusion

There is room for improvement in recognizing and translating the knowledge of salt‐related health issues and the benefits of that knowledge about salt reduction into action. Future nursing interventions should incorporate individuals' cultural needs and the dietary culture of immediate family members.

Impact

This integrative review reveals that unique Chinese customs and practices reduce the effectiveness of salt reduction campaigns. The effects of education vanish without family support, resulting in suboptimal adherence to dietary salt reduction strategies.

Sodium content of restaurant dishes in China: a cross-sectional survey

Background

Sodium intake in China is extremely high and eating in restaurants is increasingly popular. Little research has explored the sodium level of restaurant dishes. The present study aims to assess the content and sources of sodium in Chinese restaurants.

Methods

Cross-sectional data were obtained from the baseline survey of the Restaurant-based Intervention Study (RIS) in 2019. A total of 8131 best-selling restaurant dishes with detailed recipes from 192 restaurants in China were included. Sodium content per 100 g and per serving were calculated according to the Chinese Food Composition Table. The proportion of restaurant dishes exceeding the daily sodium reference intake level in a single serving and the major sources of sodium were determined.

Results

Median sodium content in restaurant dishes were 487.3 mg per 100 g, 3.4 mg per kcal, and 2543.7 mg per serving. For a single serving, 74.9% of the dishes exceeded the Chinese adults’ daily adequate intake for sodium (AI, 1500 mg per day), and 62.6% of dishes exceeded the proposed intake for preventing non-communicable chronic diseases (PI, 2000 mg per day). Cooking salt was the leading source of sodium in Chinese restaurant dishes (45.8%), followed by monosodium glutamate (17.5%), food ingredients (17.1%), soy sauce (9.4%), and other condiments/seasonings (10.2%). More types of salted condiments/seasonings use were related to higher sodium level.

Conclusions

The sodium levels in Chinese restaurant dishes are extremely high and variable. In addition to cooking salt, other salted condiments/seasonings also contribute a large proportion of sodium. Coordinated sodium reduction initiatives targeting the main sources of sodium in restaurant dishes are urgently needed.

Iodine in household cooking salt no longer plays a crucial role in iodine status of residents in Tianjin, China

PURPOSE

The contribution of household cooking salt to population iodine status is decreasing in China, the applicability of the coverage rate of iodized salt (IS), proportion of adequately iodized salt (AIS), and salt iodine concentration (SIC) of household cooking salt used for iodine status assessment of residents requires further investigation.

METHODS

Through the IDD control project, 16,445 children and 4848 pregnant women were recruited from Tianjin, China and the relationship between the coverage rate of IS, proportion of AIS, SIC, and population iodine status was analyzed. Additionally, through the thyroid health survey project, 856 children with IS or noniodized salt were recruited. The effects of different household cooking salts on individual iodine status and thyroid health were analyzed.

RESULTS

After adjusting for confounding factors, no relationship was found between the coverage rate of IS, proportion of AIS, SIC of household cooking salt, and iodine status of children and pregnant women (all P > 0.05). No differences in levels of thyroid function and structural indicators were found in children with different household cooking salts (all P > 0.05). Additionally, no relationship was found between noniodized salt exposure and goiter, overt hyperthyroidism, overt hypothyroidism, thyroid nodules, antibody single positivity, or subclinical hypothyroidism (all P > 0.05).

CONCLUSION

Iodine in household cooking salt no longer plays a crucial role in iodine status in Tianjin, China. Other indicators must be identified as beneficial supplements for precise iodine status evaluation not only in Tianjin but also in other large cities in China.

Potential Impact of Time Trend of Lifestyle Risk Factors on Burden of Major Gastrointestinal Cancers in China

BACKGROUND & AIMS

China has the largest number of incident liver, esophageal, gastric, and colorectal cancer cases in 2020. Examining the time trend of relevant lifestyle risk factors would help project the trend of these gastrointestinal (GI) cancer incidence in China.

METHODS

We estimated the time trend of the lifestyle factors based on the China Health and Nutrition Survey 1991 to 2011. We applied the comparative risk assessment method to estimate the population attributable fraction of GI cancers attributable to each risk factor. We also projected the prevalence of lifestyle factors and the associated burden of GI cancer from 2011 to 2031.

RESULTS

In 2011, 56.5% of colorectal, 59.8% of gastric, 48.5% of esophageal, and 35.2% of liver cancer in China were attributable to the lifestyle risk factors under study. Smoking, sodium intake, low vegetable intake, and low fruit intake have improved over time but remained far from optimal and are expected to be responsible for 170,000, 35,000, 22,000, and 50,000 GI cancer cases in 2031, respectively. High body mass index, red and processed meat consumption, and low physical activity are expected to contribute increasingly more GI cancer, accounting for 142,000, 185,000, 60,000, and 53,000 cases in 2031, respectively. The estimated population attributable fraction for all risk factors in 2031 is 52.1%.

CONCLUSIONS

Lifestyle risk factors have had an impact on the risk of GI cancer in China, and the impact is projected to increase. If everyone could adhere to the optimal lifestyle, half of all GI cancer events would be prevented by year 2031.

Dietary sodium and cardiovascular morbidity/mortality: a brief commentary on the 'J-shape hypothesis'

The last decade, a growing number of evidence support J-shape or inverse - instead of positive linear -- associations between dietary sodium intake and cardiovascular morbidity/mortality. A careful evaluation of these studies leads to the following observations: less accurate methods for dietary sodium assessment are usually used; most studies included high-risk participants, enhancing the possibility of a 'reverse causality' phenomenon. However, these limitations do not explain all the findings. Few carefully designed randomized clinical trials comparing different levels of sodium intake that address the issue of the optimal and safe range exist; therefore, current guidelines recommend a higher cut-off instead of a safe range of intake. Given the demonstrated harmful effects of very low sodium diets leading to subclinical vascular damage in animal studies, the 'J-shape hypothesis' cannot yet be either neglected or verified. There is a great need of well-designed general population-based prospective randomized clinical trials to address the issue.

Factors Affecting Salt Reduction Measure Adoption among Chinese Residents

China has the highest mortality rate caused by diseases and conditions associated with its high-salt diet. Since 2016, China has initiated a national salt reduction campaign that aims at promoting the usage of salt information on food labels and salt-restriction spoons and reducing condiment and pickled food intake. However, factors affecting individuals’ decisions to adopt these salt reduction measures remain largely unknown. By comparing the performances of logistic regression, stepwise logistic regression, lasso logistic regression and adaptive lasso logistic regression, this study aims to fill this gap by analyzing the adoption behaviour of 1610 individuals from a nationally representative online survey. It was found that the practices were far from adopted and only 26.40%, 22.98%, 33.54% and 37.20% reported the adoption of labelled salt information, salt-restriction spoons, reduced condiment use in home cooking and reduced pickled food intake, respectively. Knowledge on salt, the perceived benefits of salt reduction, participation in nutrition education and training programs on sodium reduction were positively associated with using salt information labels. Adoption of the other measures was largely explained by people’s awareness of hypertension risks and taste preferences. It is therefore recommended that policy interventions should enhance Chinese individuals’ knowledge of salt, raise the awareness of the benefits associated with a low-salt diet and the risks associated with consuming excessive salt and reshape their taste choices.

Restaurant interventions for salt reduction in China: protocol for a randomised controlled trial

INTRODUCTION

Salt intake in China is high, and most of it comes from that added by consumers. Nevertheless, recent years have seen a rapid increase in the frequency at which people eat out. The aim of this study is to evaluate the effectiveness of interventions designed for salt reduction in restaurants through a randomised controlled trial in China.

METHODS AND ANALYSIS

As a randomised controlled trial with restaurants as study subjects, we recruited 192 restaurants from 12 counties of 6 provinces in China. After the baseline survey, restaurants were randomly assigned to intervention or control group. Using social cognitive theory, comprehensive intervention activities were designed to encourage salt reduction in all restaurant foods, and at the same time, to encourage consumers to choose lower salt options when eating out. The interventions will be conducted only in restaurants of the intervention group during the first year. The follow-up assessment will be conducted at the end of the trial. The primary outcome is the change in the average salt content of the five best-selling dishes of the restaurant, as measured by laboratory tests. Secondary outcomes include differences in the monthly use of salt and salty condiments between intervention and control restaurants, and the knowledge, attitude and practice on salt among restaurant consumers.

ETHICS AND DISSEMINATION

The study was reviewed and approved by the Review Board of the National Institute for Nutrition and Health, Chinese Center for Disease Control and Prevention and Queen Mary Research Ethics Committee. Results will be disseminated through presentations, publications and social media.

TRIAL REGISTRATION NUMBER

ChiCTR1800019694; Pre-results.

A Systematic Review of the Sources of Dietary Salt Around the World

Excess salt intake contributes to hypertension and increased cardiovascular disease risk. Efforts to implement effective salt-reduction strategies require accurate data on the sources of salt consumption. We therefore performed a systematic review to identify the sources of dietary salt around the world. We systematically searched peer-reviewed and gray literature databases for studies that quantified discretionary (salt added during cooking or at the table) and nondiscretionary sources of salt and those that provided information about the food groups contributing to dietary salt intake. Exploratory linear regression analysis was also conducted to assess whether the proportion of discretionary salt intake is related to the gross domestic product (GDP) per capita of a country. We identified 80 studies conducted in 34 countries between 1975 and 2018. The majority (n = 44, 55%) collected data on dietary salt sources within the past 10 y and were deemed to have a low or moderate risk of bias (n = 75, 94%). Thirty-two (40%) studies were judged to be nationally representative. Populations in Brazil, China, Costa Rica, Guatemala, India, Japan, Mozambique, and Romania received more than half of their daily salt intake from discretionary sources. A significant inverse correlation between discretionary salt intake and a country's per capita GDP was observed (P < 0.0001), such that for every $10,000 increase in per capita GDP, the amount of salt obtained from discretionary sources was lower by 8.7% (95% CI: 5.1%, 12%). Bread products, cereal and grains, meat products, and dairy products were the major contributors to dietary salt intake in most populations. There is marked variation in discretionary salt use around the world that is highly correlated with the level of economic development. Our findings have important implications for the type of salt-reduction strategy likely to be effective in a country.

Design and implementation of an intelligent monitoring system for household added salt consumption in China based on a real-world study: a randomized controlled trial

BACKGROUND

A high intake of salt is a major risk factor for cardiovascular diseases. Despite decades of effort to reduce salt consumption, the salt intake in China is still considerably above the recommended level. Thus, this study aims to design and implement an intelligent household added salt monitoring system (SALTCHECKER) to monitor and control added salt consumption in Chinese households.

METHODS

A randomized controlled trial will be conducted among households to test the effect of a SALTCHECKER in Chongqing, China. The test modalities are the SALTCHECKER (with a smart salt checker and a salt-limiting WeChat mini programme) compared to a salt checker (with only a weighing function). The effectiveness of the system will be investigated by assessing the daily added salt intake of each household member and the salt consumption-related knowledge, attitude and practice (KAP) of the household's main cook. Assessments will be performed at baseline and at 3 and 6 months.

DISCUSSION

This study will be the first to explore the effect of the household added salt monitoring system on the reduction in salt intake in households. If the intelligent monitoring system is found to be effective in limiting household added salt consumption, it could provide scientific evidence on reducing salt consumption and preventing salt-related chronic diseases.

TRIAL REGISTRATION

Chinese clinical trial registry (Primary registry in the World Health Organization registry network): ChiCTR1800018586. Date of registration: September 25, 2018.

Reducing Salt Intake in China with "Action on Salt China" (ASC): Protocol for Campaigns and Randomized Controlled Trials

BACKGROUND

Salt intake in China is over twice the maximum recommendation of the World Health Organization. Unlike most developed countries where salt intake is mainly derived from prepackaged foods, around 80% of the salt consumed in China is added during cooking.

OBJECTIVE

Action on Salt China (ASC), initiated in 2017, aims to develop, implement, and evaluate a comprehensive and tailored salt reduction program for national scaling-up.

METHODS

ASC consists of six programs working in synergy to increase salt awareness and to reduce the amount of salt used during cooking at home and in restaurants, as well as in processed foods. Since September 2018, two health campaigns on health education and processed foods have respectively started, in parallel with four open-label cluster randomized controlled trials (RCTs) in six provinces across China: (1) app-based intervention study (AIS), in which a mobile app is used to achieve and sustain salt reduction in school children and their families; (2) home cook-based intervention study (HIS), in which family cooks receive support in using less salt; (3) restaurant-based intervention study (RIS) targeting restaurant consumers, cooks, and managers; and (4) comprehensive intervention study (CIS), which is a real-world implementation and evaluation of all available interventions in the three other RCTs. To explore the barriers, facilitators, and effectiveness of delivering a comprehensive salt reduction intervention, these RCTs will last for 1 year (stage 1), followed by nationwide implementation (stage 2). In AIS, HIS, and CIS, the primary outcome of salt reduction will be evaluated by 24-hour urinary sodium excretion in 6030 participants, including 5436 adults and 594 school children around 8-9 years old. In RIS, the salt content of meals will be measured by laboratory food analysis of the 5 best-selling dishes from 192 restaurants. Secondary outcomes will include process evaluation; changes in knowledge, attitude, and practice on salt intake; and economic evaluation.

RESULTS

All RCTs have been approved by Queen Mary Research Ethics Committee and the Institutional Review Boards of leading institutes in China. The research started in June 2017 and is expected to be completed around March 2021. The baseline investigations of the four RCTs were completed in May 2019.

CONCLUSIONS

The ASC project is progressing smoothly. The intervention packages and tailored components will be promoted for salt reduction in China, and could be adopted by other countries.

TRIAL REGISTRATION

Chinese Clinical Trial Registry. AIS: ChiCTR1800017553; https://tinyurl.com/vdr8rpr. HIS: ChiCTR1800016804; https://tinyurl.com/w8c7x3w. RIS: ChiCTR1800019694; https://tinyurl.com/uqkjgfw. CIS: ChiCTR1800018119; https://tinyurl.com/s3ajldw.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/15933.

Trends in Adult Cooking Salt Intake - China, 1991-2018

What is already known about this topic? Sodium intake in China is among the highest in the world, the main source of which in adults is salt added during cooking. In 2012, the national average cooking salt intake was 10.5 g/d. What is added by this report? In 2018, median cooking salt intake was 6.3 g/d, which has decreased compared to that in 1991. The north-south gap in cooking salt intake was closing over time. What are the implications for public health practice? Effective policies and interventions need to be sustained and intensified to lower cooking salt intake, thus achieving the recommended level of sodium and total salt intake.

Evaluation of sex differences in dietary behaviours and their relationship with cardiovascular risk factors: a cross-sectional study of nationally representative surveys in seven low- and middle-income countries

BACKGROUND

Cardiovascular diseases (CVD) are the leading causes of death for men and women in low-and-middle income countries (LMIC). The nutrition transition to diets high in salt, fat and sugar and low in fruit and vegetables, in parallel with increasing prevalence of diet-related CVD risk factors in LMICs, identifies the need for urgent action to reverse this trend. To aid identification of the most effective interventions it is crucial to understand whether there are sex differences in dietary behaviours related to CVD risk.

METHODS

From a dataset of 46 nationally representative surveys, we included data from seven countries that had recorded the same dietary behaviour measurements in adults; Bhutan, Eswatini, Georgia, Guyana, Kenya, Nepal and St Vincent and the Grenadines (2013-2017). Three dietary behaviours were investigated: positive salt use behaviour (SUB), meeting fruit and vegetable (F&V) recommendations and use of vegetable oil rather than animal fats in cooking. Generalized linear models were used to investigate the association between dietary behaviours and waist circumference (WC) and undiagnosed and diagnosed hypertension and diabetes. Interaction terms between sex and dietary behaviour were added to test for sex differences.

RESULTS

Twenty-four thousand three hundred thirty-two participants were included. More females than males reported positive SUB (31.3 vs. 27.2% p-value < 0.001), yet less met F&V recommendations (13.2 vs. 14.8%, p-value< 0.05). The prevalence of reporting all three dietary behaviours in a positive manner was 2.7%, varying by country, but not sex. Poor SUB was associated with a higher prevalence of undiagnosed hypertension for females (13.1% vs. 9.9%, p-value = 0.04), and a higher prevalence of undiagnosed diabetes for males (2.4% vs. 1.5%, p-value = 0.02). Meeting F&V recommendations was associated with a higher prevalence of high WC (24.4% vs 22.6%, p-value = 0.01), but was not associated with undiagnosed or diagnosed hypertension or diabetes.

CONCLUSION

Interventions to increase F&V intake and positive SUBs in the included countries are urgently needed. Dietary behaviours were not notably different between sexes. However, our findings were limited by the small proportion of the population reporting positive dietary behaviours, and further research is required to understand whether associations with CVD risk factors and interactions by sex would change as the prevalence of positive behaviours increases.

Salt content of sauces in the UK and China: cross-sectional surveys

OBJECTIVES

(1) To assess the changes in the salt content of sauces in the UK in the past 10 years; (2) to compare the salt content of sauces in China with equivalent products sold in the UK and (3) to calculate the proportion of sauce products meeting the salt targets set by the UK Department of Health (DoH).

DESIGN

Cross-sectional surveys from the nutrition information panels of sauces.

SETTING

Major retailers in London, Beijing and Shijiazhuang operating at data collection times.

MAIN OUTCOME MEASURE

Salt content of sauces.

RESULTS

Relative change in the median salt content of UK products ranged from -70.6% to +3.0% in sauces for which salt targets were set, whereas it ranged from -27.1% to +111.5% in sauces without targets. Median salt contents were on average 4.4-fold greater in Chinese sauces compared with their UK equivalents surveyed during the same period (2015-2017). Only 13.4% of the Chinese products met the UK 2017 salt targets, compared with 70.0% of UK products.

CONCLUSION

In the UK, the target-based approach contributed to the reduction in the salt content of sauces over the course of the past 10 years. Currently, large variations in salt content exist within the same categories of sauces and 70% of the products have met DoH's 2017 targets, demonstrating that further reductions are possible and lower salt targets should be set. In China, salt content of sauces is extremely high with similarly large variations within same categories of sauces, demonstrating the feasibility of reducing their salt content. As processed foods (including sauces) are expected to become an important contributor to salt intake in China, national salt reduction efforts such as setting salt targets would be a valuable, proactive strategy.

Dietary Sources of Salt in Low- and Middle-Income Countries: A Systematic Literature Review

Rapid urbanization in low- and middle-income countries (LMICs) is transforming dietary patterns from reliance on traditional staples to increased consumption of energy-dense foods high in saturated fats, trans fats, sugars, and salt. A systematic literature review was conducted to determine major food sources of salt in LMICs that could be targeted in strategies to lower population salt intake. Articles were sourced using Medline, Web of Science, Scopus, and grey literature. Inclusion criteria were: reported dietary intake of Na/salt using dietary assessment methods and food composition tables and/or laboratory analysis of salt content of specific foods in populations in countries defined as low or middle income (LMIC) according to World Bank criteria. Of the 3207 records retrieved, 15 studies conducted in 12 LMICs from diverse geographical regions met the eligibility criteria. The major sources of dietary salt were breads, meat and meat products, bakery products, instant noodles, salted preserved foods, milk and dairy products, and condiments. Identification of foods that contribute to salt intake in LMICs allows for development of multi-faceted approaches to salt reduction that include consumer education, accompanied by product reformulation.

Sociodemographic patterns of urine sodium excretion and its association with hypertension in Chile: a cross-sectional analysis

OBJECTIVE

The aim of the study was to determine the main factors (sociodemographic, anthropometric, lifestyle and health status) associated with high Na excretion in a representative population of Chile.

DESIGN

Na excretion (g/d), a valid marker of Na intake, was determined by urine analysis and Tanaka's formulas. Blood pressure was measured by trained staff and derived from the mean of three readings recorded after 15 min rest. The associations of Na excretion with blood pressure and the primary correlates of high Na excretion were determined using logistic regression.

SETTING

Chileans aged ≥15 years.ParticipantsParticipants (n 2913) from the Chilean National Health Survey 2009-2010.

RESULTS

Individuals aged 25 years or over, those who were obese and those who had hypertension, diabetes or metabolic syndrome were more likely to have higher Na excretion. The odds for hypertension increased by 10·2 % per 0·4 g/d increment in Na excretion (OR=1·10; 95 % CI 1·06, 1·14; P &lt; 0·0001). These findings were independent of major confounding factors.

CONCLUSIONS

Age, sex, adiposity, sitting behaviours and existing co-morbidities such as diabetes were associated with higher Na excretion levels in the Chilean population. These findings could help policy makers to implement public health strategies tailored towards individuals who are more likely to consume high levels of dietary salt.

Association between urinary sodium excretion and coronary heart disease in hospitalized elderly patients in China

Objective

This study was performed to evaluate the association between urinary sodium excretion and coronary heart disease (CHD) in hospitalized elderly patients in China.

Methods

The 24-h urinary excretion specimens of 541 patients were collected, and the serum creatinine concentration and urinary sodium/potassium ratio were measured. Associations were explored by multivariate logistic regression analysis.

Results

The mean 24-h urinary sodium excretion was 200.4 mmol, corresponding to 11.7 g of salt intake. Both of these values were higher in men than in women. The salt intake of 80- to 89-year-old patients was significantly lower than that of 70- to 79-year-old patients. The 24-h urinary sodium excretion and spot urine Na/K ratios were significantly higher in overweight/obese and hypertensive patients. The 24-h urinary sodium excretion of men who smoked was significantly higher than that of women. The spot urine Na/K ratio was significantly higher in patients with cerebral thrombosis. The urinary Na/K ratio, smoking status, and hypertension were independent risk factors for CHD.

Conclusions

This cross-sectional survey suggests that the Na/K ratio may better represent salt loading than Na excretion alone in studying the association between sodium intake and CHD. There was no association between sodium and CHD prevalence.

Adoptable Interventions, Human Health, and Food Safety Considerations for Reducing Sodium Content of Processed Food Products

Although vital for maintaining health when consumed in moderation, various epidemiological studies in recent years have shown a strong association between excess dietary sodium with an array of health complications. These associations are robust and clinically significant for development of hypertension and prehypertension, two of the leading causes of preventable mortality worldwide, in adults with a high-sodium diet. Data from developed nations and transition economies show worldwide sodium intake of higher than recommended amounts in various nations. While natural foods typically contain a moderate amount of sodium, manufactured food products are the main contributor to dietary sodium intake, up to 75% of sodium in diet of American adults, as an example. Lower cost in formulation, positive effects on organoleptic properties of food products, effects on food quality during shelf-life, and microbiological food safety, make sodium chloride a notable candidate and an indispensable part of formulation of various products. Although low-sodium formulation of each product possesses a unique set of challenges, review of literature shows an abundance of successful experiences for products of many categories. The current study discusses adoptable interventions for product development and reformulation of products to achieve a modest amount of final sodium content while maintaining taste, quality, shelf-stability, and microbiological food safety.

Differences in nutrient and energy contents of commonly consumed dishes prepared in restaurants v. at home in Hunan Province, China

OBJECTIVE

Eating away from home is associated with poor diet quality, in part due to less healthy food choices and larger portions. However, few studies account for the potential additional contribution of differences in food composition between restaurant- and home-prepared dishes. The present study aimed to investigate differences in nutrients of dishes prepared in restaurants v. at home.

DESIGN

Eight commonly consumed dishes were collected in twenty of each of the following types of locations: small and large restaurants, and urban and rural households. In addition, two fast-food items were collected from ten KFC, McDonald's and food stalls. Five samples per dish were randomly pooled from every location. Nutrients were analysed and energy was calculated in composite samples. Differences in nutrients of dishes by preparation location were determined.

SETTING

Hunan Province, China.

SUBJECTS

Na, K, protein, total fat, fatty acids, carbohydrate and energy in dishes.

RESULTS

On average, both the absolute and relative fat contents, SFA and Na:K ratio were higher in dishes prepared in restaurants than households (P < 0·05). Protein was 15 % higher in animal food-based dishes prepared in households than restaurants (P<0·05). Quantile regression models found that, at the 90th quantile, restaurant preparation was consistently negatively associated with protein and positively associated with the percentage of energy from fat in all dishes. Moreover, restaurant preparation also positively influenced the SFA content in dishes, except at the highest quantiles.

CONCLUSIONS

These findings suggest that compared with home preparation, dishes prepared in restaurants in China may differ in concentrations of total fat, SFA, protein and Na:K ratio, which may further contribute, beyond food choices, to less healthy nutrient intakes linked to eating away from home.

Effects of salt substitute on home blood pressure differs according to age and degree of blood pressure in hypertensive patients and their families

BACKGROUND

It is known that home blood pressure (HBP) is a more reliable assessment of hypertension treatments than clinical blood pressure (BP). Despite this, HBP response to a salt substitute has only been evaluated by one study which, did not look at the salt substitute's effect on family members and did not analyze by age, gender, or BP degree. The aim of this current study was to assess the effects of a low-sodium and high-potassium salt substitute on HBP among hypertensive patients and their family members.

METHODS

A total of 220 households (including 220 hypertensive patients and 380 their families) were randomly assigned to the regular salt or salt substitute groups. HBP was measured at the beginning, 3rd, 6th, and 12th months. Among the patients (n = 220), only home systolic blood pressure (HSBP) was significantly reduced, by an adjusted baseline BP of 4.2 mm Hg (95% CI: 1.3-7.0 mm Hg), in the salt substitute group compared with those in the regular salt group at each visit (all P < 0.05). There were no detectable differences between groups for home diastolic blood pressure (HDBP) at any visit. Among the family members, HSBP and HDBP were not significantly different between the groups. Furthermore, Individuals ≥60 years old, hypertensive patients with stage-2 hypertension, family members with hypertension, and women experienced greater HSBP reduction.

CONCLUSIONS

Older subjects, those with higher blood pressure, and women experienced greater home blood pressure reduction from the salt substitute compared to regular salt.

Salt Use Behaviours of Ghanaians and South Africans: A Comparative Study of Knowledge, Attitudes and Practices

Salt consumption is high in Africa and the continent also shares the greatest burden of hypertension. This study examines salt-related knowledge, attitude and self-reported behaviours (KAB) amongst adults from two African countries—Ghana and South Africa—which have distributed different public health messages related to salt. KAB was assessed in the multinational longitudinal World Health Organisation (WHO) study on global AGEing and adult health (WHO-SAGE) Wave 2 (2014–2015). Respondents were randomly selected across both countries—Ghana (n = 6746; mean age 58 years old; SD 17; 41% men; 31% hypertensive) and South Africa (n = 3776, mean age 54 years old; SD 17; 32% men; 45% hypertensive). South Africans were more likely than Ghanaians to add salt to food at the table (OR 4.80, CI 4.071–5.611, p < 0.001) but less likely to add salt to food during cooking (OR 0.16, CI 0.130–0.197, p < 0.001). South Africans were also less likely to take action to control their salt intake (OR 0.436, CI 0.379–0.488, p < 0.001). Considering the various salt reduction initiatives of South Africa that have been largely absent in Ghana, this study supports additional efforts to raise consumer awareness on discretionary salt use and behaviour change in both countries.

Dietary Sources of High Sodium Intake in Turkey: SALTURK II

Previous research has shown daily salt intakes in Turkey to be far above the recommended limits. Knowing the sources of dietary salt could form a basis for preventive strategies aimed towards salt reduction. This study aimed to investigate dietary sources of salt in Turkey. A sub-group (n = 657) was selected from the PatenT2 study population, which represented the urban and rural areas of 4 major cities (Ankara, Istanbul, Izmir, and Konya). A questionnaire inquiring about sociodemographic characteristics, medical histories, detailed histories of diet, and salt consumption was completed. Participants were asked to collect a 24-h urine sample and to record their food intake (dietary recall) on the same day. Of 925 participants selected, 657 (71%) provided accurate 24-h urine collections, based on creatinine excretion data. The mean daily 24-h urinary sodium excretion was 252.0 ± 92.2 mmol/day, equal to daily salt intake of 14.8 ± 5.4 g. Of the 657 participants with accurate 24-h urine collections, 464 (70%) provided fully completed dietary recalls. Among these 464 participants, there was a significant difference between the 24-h urinary sodium excretion-based salt intake estimation (14.5 ± 5.1 g/day) and the dietary recall-based salt intake estimation (12.0 ± 7.0 g/day) (p < 0.001). On the other hand, a positive correlation was obtained between the dietary recall-based daily salt intake and 24-h urinary sodium excretion-based daily salt intake (r = 0.277, p < 0.001). Bread was the main source of salt (34%) followed by salt added during cooking and preparing food before serving (30%), salt from various processed foods (21%), and salt added at the table during food consumption (11%). Conclusively, this study confirmed a very high salt intake of the adult population in four major cities in Turkey. The present findings support the emerging salt reduction strategy in Turkey by promoting lower salt content in baked bread, and less salt use in habitual food preparation and during food consumption in the home.

Food Sources of Sodium Intake in an Adult Mexican Population: A Sub-Analysis of the SALMEX Study

Excessive dietary sodium intake increases blood pressure and cardiovascular risk. In Western diets, the majority of dietary sodium comes from packaged and prepared foods (≈75%); however, in Mexico there is no available data on the main food sources of dietary sodium. The main objective of this study was to identify and characterize the major food sources of dietary sodium in a sample of the Mexican Salt and Mexico (SALMEX) cohort. Adult male and female participants of the SALMEX study who provided a complete and valid three-day food record during the baseline visit were included. Overall, 950 participants (mean age 38.6 ± 10.7 years) were analyzed to determine the total sodium contributed by the main food sources of sodium identified. Mean daily sodium intake estimated by three-day food records and 24-h urinary sodium excretion was 2647.2 ± 976.9 mg/day and 3497.2 ± 1393.0, in the overall population, respectively. Processed meat was the main contributor to daily sodium intake, representing 8% of total sodium intake per capita as measured by three-day food records. When savory bread (8%) and sweet bakery goods (8%) were considered together as bread products, these were the major contributor to daily sodium intake, accounting for the 16% of total sodium intake, followed by processed meat (8%), natural cheeses (5%), and tacos (5%). These results highlight the need for public health policies focused on reducing the sodium content of processed food in Mexico.

Salt reduction in China: a state-of-the-art review

Objective

This study aimed to reveal the latest evidence on salt reduction initiatives in China in order to identify the contextual cost-effective interventions, as well as the barriers encountered during China’s long march to reach its population salt reduction goal.

Background

Population-based salt reduction has been considered as one of the most cost-effective strategies in the world for the prevention and control of noncommunicable diseases. China, along with its sustained economic growth, faces increasing burdens from chronic diseases such as cardiovascular and kidney diseases. With policy support and cross-sector collaboration, various salt reduction initiatives have been adopted in China in order to reduce such dietary risk, especially since the beginning of this millennium.

Methods

This study conducted structured literature reviews in both English and Chinese databases and synthesized the latest evidence on the association of salt intake and health, as well as salt intake among Chinese and population-based salt reduction strategies in China and around the world.

Findings

Dietary salt restriction has been found to contribute to the reduction of blood pressure among both the normotensives and hypertensives bringing associated reduced disease burdens and great public health benefits. With gender, ethnic, and regional variations, salt intake levels in the population in China are well above the recommended threshold and physiological need. Admittedly, excessive salt intake precipitates the high prevalence of hypertension and cardiovascular disease among the Chinese. Considering that the majority of the dietary salt is added during cooking in China, salt substitutes, salt restriction tools, and health education are the most common salt reduction initiatives with varying levels of effectiveness and acceptability among the Chinese population.

Implication

Overwhelming evidence is in support of a well-coordinated nationwide salt restriction initiative as a key public health strategy for the prevention and control of hypertension and its related diseases. Orchestrated efforts from the government, industries, academia, health professionals, and the general public are required to achieve China’s long-term goal for salt reduction.