Dietary counselling to reduce moderate sodium intake: effects on cardiovascular and renal biomarkers: primary findings of the COSIP and STICK phase II feasibility randomised controlled trials

Manufacture of Low-Na White Soft Brined Cheese: Effect of NaCl Substitution with a Combination of Na-K Salts on Proximate Composition, Mineral Content, Microstructure, and Sensory Acceptance

All over the world, especially in Western societies, table salt intake that is inordinately higher than the acceptable level has been observed. An excess of Na in the human diet, mostly from processed foods, is becoming the "number one killer", leading to increased blood pressure. Therefore, the food industry is faced with a need to reduce Na in human nutrition in an effort to raise public health protection to a higher level. In this study, a commercially available combination of Na/K salts (COMB) at different concentrations was used as a NaCl substitute in the production of a modified, healthier, Na-reduced cheese. Samples of the modified low-Na white soft-brined cheese (WSBC) were produced by adding four different concentrations of COMB to production lots PL-1 to PL-4, and the control (CON) samples were prepared by salting with the usual, non-reduced concentration of NaCl. The effects of NaCl replacement on the physical-chemical parameters, major- and micro-elements, and microstructural and sensory properties of the WSBC were investigated. The obtained results indicated that there was no significant influence on the ash content, pH, and aw. The Na and K levels differed among treatments (p < 0.001). The lowest Na level in this study was recorded in PL-4 (only COMB was added) and was 334.80 ± 24.60 mg/100 g. According to the Na content, WSBC PL4 can be labeled with the nutrient claim "reduced amount of Na". A significant difference (p < 0.05) was noticed in overall acceptance between the CON and PL-4, with no statistically significant difference found amongst other WSBC production lots. The replacement of NaCl resulted in a slightly greater firmness of the WSBC. The results confirm the possibility of producing low-Na WSBC when optimal amounts of a suitable mineral salt are used as a substitute for NaCl, thus reducing the risk of high Na intake in the human body through the consumption of evaluated cheese.

Age differences in the impact of dietary salt on metabolism, blood pressure and cognitive function in male rats

The influence of salt consumption on physiological processes, especially blood pressure (BP), metabolism, and cognition, remains a topical concern. While guidelines endorse reduced salt diets, there are gaps in understanding the age-specific implications and challenges in adherence. The present study delved into the differential effects of salt intake on young adult and aged male rats over a 12-week period, using control, low-, and high-salt diets. Key metrics, such as BP, cognition, and general parameters, were monitored. Our findings revealed significant age-dependent effects of salt intake on survival rates, body weight, blood sodium, blood glucose, blood lipids, BP, heart rates, and cognition. Notably, young adult rats did not show significant sodium level changes on a high-salt diet, whereas aged rats experienced increased sodium levels even on a normal salt diet. Blood glucose levels decreased significantly in aged rats on a high-salt diet but remained stable in young adults. Aged rats had the highest survival rates on low-salt diets. Low-salt diets led to reduced BP in both age groups, more significantly in young adults. Young adult rats displayed increased BP variability on both high- and low-salt diets, while a decrease in BP variability was exclusive to aged rats on a low-salt diet. There were significant differences across age groups in short-term memory, but not in long-term memory. The study provides a nuanced understanding of the age-dependent physiological effects of salt intake, suggesting the necessity of age-specific guidelines for public health.

Salt restriction for treatment of hypertension - current state and future directions

PURPOSE OF REVIEW

Given the adverse effects of excess dietary sodium chloride (also known as table salt) on blood pressure (BP) and cardiovascular disease (CVD), restriction of dietary sodium is recommended by numerous guidelines. The strictest of these recommend no more than 1.5 g/day of dietary sodium among hypertensive persons. However, average dietary sodium intake in the population is closer to 5 g/day and there is debate about whether too much sodium restriction may be associated with increased CVD risk. Herein, we aim to provide a balanced update on this topic.

RECENT FINDINGS

In 2021, the Salt Substitute and Stroke Study (SSaSS) demonstrated a significant reduction in BP, CVD, and death among Chinese adults randomized to a low sodium salt-substitute supplemented with potassium. This trial largely puts to rest any remaining debate about the benefits of dietary sodium restriction among persons with excess baseline intake (dietary sodium intake fell from approximately 5 down to 4 g/day in the active arm of SSaSS). However, whether achieving and maintaining a dietary sodium of less than1.5 g/day is feasible in real-world settings and whether this low an intake is harmful remain open questions.

SUMMARY

Aiming for sodium intakes of 2--3 g/day in the general population and as low as 2 g/day in persons with hypertension or CVD seems most reasonable, but there is some uncertainty around lower targets.

A low dietary sodium dose is associated with a more pronounced aldosterone response in normotensive than in hypertensive individuals

In this comprehensive meta-regression analysis encompassing 79 randomized controlled trials, we observed that in populations assigned to a high sodium intake level exceeding 94 mmol, there was no discernible link between plasma aldosterone levels and sodium intake. However, among populations with normal blood pressure subjected to a lower sodium intake, falling below 111 mmol (N = 1544), the association between sodium intake and plasma aldosterone levels manifested as a decrease of 192 pg/ml per 100 mmol of sodium (95% CI - 303 to - 81). In hypertensive populations (N = 1145), this association was less pronounced, with a reduction of 46 pg/ml per 100 mmol sodium, (95% CI - 112 to 20). Furthermore, in normotensive populations the plasma aldosterone increase associated with a decrease in sodium intake was 70 pg/ml per 100 mmol sodium (95% CI 27 to 113). In hypertensive populations, the observed increase was more modest, at 30 pg/ml per 100 mmol sodium, (95% CI 6.8 to 54). A limitation of this study lies in the absence of individual participant data. Our analysis included adjustments for potential effect-modifiers, encompassing bias estimation, which did not substantially alter these associations. One perspective of the present results may be to prompt a reconsideration of current sodium reduction recommendations.

Global cardiovascular diseases burden attributable to high sodium intake from 1990 to 2019

Sodium intake shows a positive correlation with blood pressure, resulting in an increased risk for cardiovascular diseases (CVD). Salt reduction is a key step toward the WHO's goal of 25% reduction in mortality from non-communicable diseases (NCDs) by 2025. This study aims to assess the current condition and temporal changes of the global CVD burden due to high sodium intake (HSI). We extracted data from the Global Burden of Disease (GBD) study 2019. The numbers and age-standardized rates of mortality and disability-adjusted life-years (DALYs), stratified by location, sex, and socio-demographic Index (SDI), were used to assess the high sodium intake attributable CVD burden from 1990 to 2019. The relationship between the DALYs rates and related factors was evaluated by stepwise multiple linear regression analysis. Globally, in 2019, the deaths and DALYs of HSI-related CVD were 1.72 million and 40.54 million, respectively, increasing by 41.08% and 33.06% from 1990. Meanwhile, the corresponding mortality and DALYs rates dropped by 35.1% and 35.2%, respectively. The high-middle and middle SDI quintiles bore almost two-thirds of CVD burden caused by HSI. And the leading cause of HSI attributable CVD burden was ischemic heart disease. Universal health coverage (UHC) was associated with the DALYs rates after adjustment. From 1990 to 2019, the global CVD burden attributable to HSI has declined with spatiotemporal and sexual heterogeneity. However, it remains a major public health challenge because of the increasing absolute numbers. Improving UHC serves as an effective strategy to reduce the HSI-related CVD burden.