Sodium and Salt Consumption in Latin America and the Caribbean: A Systematic-Review and Meta-Analysis of Population-Based Studies and Surveys

Monitoring sodium content in processed and ultraprocessed foods in Argentina 2022: compliance with National Legislation and Regional Targets

OBJECTIVE

To assess the current Na levels in a variety of processed food groups and categories available in the Argentinean market to monitor compliance with the National Law and to compare the current Na content levels with the updated Pan American Health Organisation (PAHO) regional targets.

DESIGN

Observational cross-sectional study.

SETTING AND PARTICIPANTS

Argentina. Data were collected during March 2022 in the city of Buenos Aires in two of the main supermarket chains. We carried out a systematic survey of pre-packaged food products available in the food supply assessing Na content as reported in nutrition information panels.

RESULTS

We surveyed 3997 food products, and the Na content of 760 and 2511 of them was compared with the maximum levels according to the Argentinean law and the regional targets, respectively. All food categories presented high variability of Na content. More than 90 % of the products included in the National Sodium Reduction Law were found to be compliant. Food groups with high median Na, such as meat and fish condiments, leavening flour and appetisers are not included in the National Law. In turn, comparisons with PAHO regional targets indicated that more than 50 % of the products were found to exceed the regional targets for Na.

CONCLUSIONS

This evidence suggests that it is imperative to update the National Sodium Reduction Law based on regional public health standards, adding new food groups and setting more stringent legal targets.

Sodium and potassium excretion and its association with cardiovascular disorders in Mexican adults

Worldwide, as well as in Mexico, the leading cause of death is cardiovascular disease (CVD). Hypertension is the main risk factor for CVD; about 50% of the adult population suffers from this condition. High sodium (Na) intake combined with low potassium (K) intake can trigger cardiovascular disorders such as high blood pressure (BP). The aim of this study was to estimate the mean excretion of Na and K in Mexican adults using a spot urine sample, and its association with cardiovascular disorders. Information on 2,778 adults, 20-59 years of age, who participated in ENSANUT-2016 was analyzed. Na and K were estimated using Tanaka formulae. Biomarkers such as glucose, total cholesterol, triglycerides, HDL cholesterol and LDL cholesterol, and anthropometry were measured. Mean Na was 3,354 mg/day (95%CI: 3,278, 3,429), 1,440 mg/day of K (95%CI: 1,412, 1,469), and the Na-K ratio was 2.4. The excretion of Na was greater in adults with high BP (3,542 mg/day) compared to those with normal BP (3,296 mg/day). In adults with hypertension, excretion of K was 10% greater (1,534 mg/day) than in adults with normal BP (1,357 mg/day). In adults with moderate reduction of renal function, Na excretion was 22% less (2,772 mg/day) than in adults with normal kidney function (3,382 mg/day). The results of this study show that the cardiovascular health of Mexican adults is at risk, as they showed high Na excretion and low K excretion.

Effective and Scalable Interventions to Reduce Sodium Intake: a Systematic Review and Meta-Analysis

PURPOSE OF REVIEW

High-sodium intake is a main risk factor for increased blood pressure and cardiovascular disease, the leading cause of death worldwide. Reducing sodium intake at the population level is one of the most cost-effective strategies to address this. The aim of the present systematic review and meta-analysis are to examine data from recent studies that measure the effectiveness and scalability of interventions aimed at reducing sodium intake at both the population and individual level.

RECENT FINDINGS

Worldwide, sodium intake is higher than the World Health Organization recommendations. Structural interventions such as mandatory reformulation of foods, food labeling, taxes or subsidies, and communication campaigns have shown to be the most effective in reducing the population's sodium consumption. Interventions in education, particularly those that use a social marketing framework with short duration, food reformulation, and combined strategies, have the potential to decrease sodium intake.

Sodium content in commonly consumed away-from-home food in three areas of Metropolitan Lima, Peru

The aim of this study was to characterize the sodium content in commonly consumed away-from-home food in three areas of Metropolitan Lima. We conducted a cross-sectional study, in which twenty frequently consumed foods were identified according to the place of sale. Sodium content was determined through atomic absorption spectroscopy in preparations collected in 2019. The median sodium content in street food products was 492.36 mg/100g (IQR: 83.93 - 918.78), 471.37 mg/100 g in artisanal food (IQR: 76.04 - 765.39) and 471.06 mg/100 g in fast food (IQR: 115.31 - 695.18). Sixty-five percent of the foods were classified as having high sodium content according to Peruvian regulations, while 30% of the preparations had high sodium content, according to UK parameters. Most food sold and consumed away from home have high sodium content. It is essential to engage all stakeholders involved in food preparation for away-from-home consumption in order to raise awareness and involve them in the promotion of policies aimed at reducing sodium intake.

Modelling the impact of sodium intake on cardiovascular disease mortality in Mexico

BACKGROUND

Cardiovascular diseases (CVD) represent the main cause of death in Mexico, while high blood pressure is suffered by about half of the adult population. Sodium intake is one of the main risk factors for these diseases. The Mexican adult population consumes about 3.1 g/day, an amount that exceeds what is recommended by the World Health Organization (WHO) < 2 g sodium/day. The objective of this study was to estimate the impact of reducing sodium intake on CVD mortality in Mexico using a scenario simulation model.

METHODS

The Integrated Model of Preventable Risk (PRIME) was used to estimate the number of deaths prevented or postponed (DPP) due to CVD in the Mexican adult population following the following sodium intake reduction scenarios: (a) according to the WHO recommendations; (b) an "optimistic" reduction of 30%; and (c) an "intermediate" reduction of 10%.

RESULTS

The results show that a total of 27,700 CVD deaths could be prevented or postponed for scenario A, 13,900 deaths for scenario B, and 5,800 for scenario C. For all scenarios, the highest percentages of DPP by type of CVD are related to ischemic heart disease, hypertensive disease, and stroke.

CONCLUSIONS

The results show that if Mexico considers implementing policies with greater impact to reduce sodium/salt consumption, a significant number of deaths from CVD could be prevented or postponed.

24-hour sodium and potassium excretion in the Americas: a systematic review and meta-analysis

Objective

To determine the 24-hour urinary sodium and potassium excretions in the Americas.

Methods

A systematic review and meta-analysis were performed seeking for studies conducted between 1990 and 2021 in adults living in any sovereign state of the Americas in Medline, Embase, Scopus, SciELO, and Lilacs. The search was first run on October 26th, 2020 and was updated on December 15th, 2021. Of 3 941 abstracts reviewed, 74 studies were included from 14 countries, 72 studies reporting urinary sodium (27 387 adults), and 42 studies reporting urinary potassium (19 610 adults) carried out between 1990 and 2020. Data were pooled using a random-effects meta-analysis model.

Results

Mean excretion was 157.29 mmol/24h (95% CI, 151.42-163.16) for sodium and 57.69 mmol/24h (95% CI, 53.35-62.03) for potassium. When only women were considered, mean excretion was 135.81 mmol/24h (95% CI, 130.37-141.25) for sodium and 51.73 mmol/24h (95% CI, 48.77-54.70) for potassium. In men, mean excretion was 169.39 mmol/24h (95% CI, 162.14-176.64) for sodium and 62.67 mmol/24h (95% CI, 55.41-69.93) for potassium. Mean sodium excretion was 150.09 mmol/24h (95% CI, 137.87-162.30) in the 1990s and 159.79 mmol/24h (95% CI, 151.63-167.95) in the 2010s. Mean potassium excretion was 58.64 mmol/24h (95% CI, 52.73-64.55) in the 1990s and 56.33 mmol/24/h (95% CI, 48.65-64.00) in the 2010s.

Conclusions

These findings suggest that sodium excretions are almost double the maximum level recommended by the World Health Organization and potassium excretions are 35% lower than the minimum requirement; therefore, major efforts to reduce sodium and to increase potassium intakes should be implemented.

Mean population salt intake in Iran: A systematic review and meta-analysis

Introduction

High salt intake has been connected with the increase of many non-communicable diseases (NCDs) worldwide. Like other middle-income countries, Iran is experiencing a considerable increase in NCDs, necessitating attempts to reduce dietary salt intake. As in Iran there is uncertainty about the existing rate of salt intake. The present study aimed to estimate mean salt intake of Iranian population by systematically reviewing existing literature.

Methods

This research is a systematic review and meta-analysis (PRISMA Protocol) of published article data, with no time constraint until the end of 2020, to estimate mean salt intake of Iranian population. A comprehensive literature search was performed on international databases of Medline, Science Direct, PubMed, Embase, Scopus, Springer, Online Library Wiley, Web of Science, Cochrane, and Google Scholar and domestic data bases of Iranmedex, Magiran, SID, and Medlib. Subgroup analysis was conducted for gender, region, measurement method, and age group. Research homogeneity was evaluated by I 2 statistic. We reviewed all studies which met inclusion criteria. STATA Ver.13.1 was used to perform meta-analysis.

Results

Meta-analysis of data from 32 studies showed that the average salt intake in all ages was 9.674 g/day (95% CI, 9.033-10.316 g/day). The lowest estimation of salt intake was 9.33 g/day (95% CI, 7.75-10.91 g/day) which was estimated from studies which used point collection method, and the highest estimate using the food reminder questionnaire was 10.41 g/day (95% CI, 8.49-12.34 g/day). Also, the average weight salt intake for men over 18 years old in different cities was 10.39 g/day (95% CI, 9.01-11.78 g/day), for women over 18 years in different cities 9.52 g/day (95% CI, 8.42-10.62 g/day), and children and adolescents was estimated at 5.664 g/day (95% CI, 2.91-8.41 g/day).

Conclusion

The intake of salt in the Iranian population is near twice the WHO recommendation. Therefore, it is necessary to consider effective strategies and interventions to reduce dietary salt intake in Iran as a health priority.

Estimation of Sodium Availability and Food Sources from 2018 to 2019 and Its Trends during the 2004-2019 Period in Costa Rica

Sodium availability and food sources in 2018−2019 were estimated and trends analyzed for 15 years (2004−2019) in Costa Rica. Food purchase records from the National Household Income and Expenditure Survey (ENIGH) 2018−2019 were converted to energy and sodium using food composition tables measuring “apparent consumption”. Foods were classified by sodium content. ENIGH is a probabilistic, stratified, two-stage and replicated national survey, carried out regularly by the national statistics institution. Results from the 2004−2005 and 2012−2013 ENIGHs came from previous analysis. Differences between periods were determined through descriptive and inferential statistics. The available sodium adjusted to 2000 kcal/person/day was 3.40, 3.86, and 3.84 g/person/day (g/p/d) for periods 2004−2005, 2013−2014, and 2018−2019, respectively. In this last period, this was 3.94 urban and 3.60 g/p/d rural (p < 0.05), with a non-linear increase with income. During 2004−2019 sodium from salt and salt-based condiments increased from 69.5 to 75.5%; the contribution of common salt increased, from 60.2 to 64.8% and condiments without added salt from 9.3 to 10.7%. From 2012−2013 to 2018−2019, processed and ultra-processed foods with added sodium intake increased from 14.2 to 16.9% and decreased in prepared meals (7.2 to 2.8%). Costa Rica has been successful in reducing salt/sodium available for consumption; after a 12% increase of salt consumption between 2004−2005 and 2012−2013, to a level almost twice as high as recommended, it has stabilized in the last period.

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.

Development, validation and application of a machine learning model to estimate salt consumption in 54 countries

Global targets to reduce salt intake have been proposed but their monitoring is challenged by the lack of population-based data on salt consumption. We developed a machine learning (ML) model to predict salt consumption at the population level based on simple predictors and applied this model to national surveys in 54 countries. We used 21 surveys with spot urine samples for the ML model derivation and validation; we developed a supervised ML regression model based on: sex, age, weight, height, systolic and diastolic blood pressure. We applied the ML model to 54 new surveys to quantify the mean salt consumption in the population. The pooled dataset in which we developed the ML model included 49,776 people. Overall, there were no substantial differences between the observed and ML-predicted mean salt intake (p<0.001). The pooled dataset where we applied the ML model included 166,677 people; the predicted mean salt consumption ranged from 6.8 g/day (95% CI: 6.8-6.8 g/day) in Eritrea to 10.0 g/day (95% CI: 9.9-10.0 g/day) in American Samoa. The countries with the highest predicted mean salt intake were in Western Pacific. The lowest predicted intake was found in Africa. The country-specific predicted mean salt intake was within reasonable difference from the best available evidence. A ML model based on readily available predictors estimated daily salt consumption with good accuracy. This model could be used to predict mean salt consumption in the general population where urine samples are not available.

Salt intake and blood pressure in Iranian children and adolescents: a population-based study

BACKGROUND

Previous studies have reported a high prevalence of hypertension in Iranian students, especially in rural areas. The aim of this study was to investigate the daily intake of salt in students and its association with high blood pressure.

METHODS

A random sub-sample was selected from the participants of the second phase of Shahroud schoolchildren eye cohort study and then a random urine sample was tested for sodium, potassium and creatinine. Urine electrolyte esexcretion and daily salt intake were calculated by Tanaka et al.'s formula.

RESULTS

Among 1455 participants (including 230 participants from rural area and 472 girls), the mean age was 12.9 ± 1.7 year and the mean daily salt intake was 9.7 ± 2.6 g (95% CI 9.5-9.8). The mean salt consumption in rural areas [10.8 (95% CI 10.4-11.2)] was higher than urban areas [9.4 (95% CI 9.3-9.6)], in people with hypertension [10.8 (95% CI 10.3-11.3)] was more than people with normal blood pressure [9.4 (95% CI 9.3-9.6)], and in boys [9.8 (95% CI 9.7-10.0)] was more than girls [9.3 (95% CI 9.1-9.6)]. Higher age, BMI z-score, male sex and rural life, were associated with increased daily salt intake. Increased salt intake was associated with increased systolic and diastolic blood pressure.

CONCLUSION

Daily salt intake in Iranian adolescents was about 2 times the recommended amount of the World Health Organization, was higher in rural areas and was associated with blood pressure. Reducing salt intake should be considered as an important intervention, especially in rural areas.

The burden of hypertension in Ecuador: a systematic review and meta-analysis

Hypertension is a major risk factor of cardiovascular diseases, which occurrence has increased consistently worldwide. With this in mind, this review was designed to evaluate the prevalence of hypertension in Ecuador. We systematically searched publications in Medline, Cumulative Index of Nursing and Allied Health Literature, Cochrane Database, and Ibero-America electronic databases for articles published through September 2019 and reporting the prevalence of hypertension in Ecuador. Selected data were subjected to meta-analysis, and pooled prevalence and their 95% (95% CI) were calculated. Seventeen articles have been selected according to the inclusion/exclusion criteria of the study. The overall estimate of the pooled prevalence of hypertension was 35.8% (CI: 31.3-38.4). Most importantly, the prevalence of hypertension increased markedly with age and obesity. Pooled estimates for the four age subdivisions (<30 years), (≥30 and ≤50 years), (>50 and ≤60 years) and (>60 years) were 9.4% (CI: 7.3-11.5), 22.0% (CI: 19.0-25.0), 26.1% (22.2-30.0) and 48.7% (CI: 45.4-52.0), respectively. Moreover, the pooled estimate of subjects with BMI ≥ 30 kg/m² (57.7%, CIs: 45.6-69.8) was markedly higher than those with BMI < 30 kg/m² (30.4%, CI: 23.3-38.4). Although limited, available data reported higher rates of hypertension in Afro-Ecuadorians than other ethnicities. This study underlines a high prevalence of hypertension in adults nationwide, but mostly in elderly and obese individuals. The magnitude of this burden emphasizes the need for robust and targeted interventions to control hypertension, and ultimately reverse the trend of cardiovascular diseases.

Activation of the Sympathetic Nervous System Promotes Blood Pressure Salt-Sensitivity in C57BL6/J Mice

Global salt intake averages >8 g/person per day, over twice the limit advocated by the American Heart Association. Dietary salt excess leads to hypertension, and this partly mediates its poor health outcomes. In ≈30% of people, the hypertensive response to salt is exaggerated. This salt-sensitivity increases cardiovascular risk. Mechanistic cardiovascular research relies heavily on rodent models and the C57BL6/J mouse is the most widely used reference strain. We examined the effects of high salt intake on blood pressure, renal, and vascular function in the most commonly used and commercially available C57BL6/J mouse strain. Changing from control (0.3% Na⁺) to high salt (3% Na⁺) diet increased systolic blood pressure in male mice by ≈10 mm Hg within 4 days of dietary switch. This hypertensive response was maintained over the 3-week study period. Returning to control diet gradually reduced blood pressure back to baseline. High-salt diet caused a rapid and sustained downregulation in mRNA encoding renal NHE3 (sodium-hydrogen-exchanger 3) and EnaC (epithelial sodium channel), although we did not observe a suppression in aldosterone until ≈7 days. During the development of salt-sensitivity, the acute pressure natriuresis relationship was augmented and neutral sodium balance was maintained throughout. High-salt diet increased ex vivo sensitivity of the renal artery to phenylephrine and increased urinary excretion of adrenaline, but not noradrenaline. The acute blood pressure-depressor effect of hexamethonium, a ganglionic blocker, was enhanced by high salt. Salt-sensitivity in commercially sourced C57BL6/J mice is attributable to sympathetic overactivity, increased adrenaline, and enhanced vascular sensitivity to alpha-adrenoreceptor activation and not sodium retention or attenuation of the acute pressure natriuresis response.