A comprehensive review on salt and health and current experience of worldwide salt reduction programmes

Exploring the novel antioxidant peptides in low-salt dry-cured ham: Preparation, purification, identification and molecular docking

Dry-cured ham is important source of bioactive peptides. In this study, the antioxidant activities of peptides and components from low and fully salted dry-cured hams were compared by peptidomics. And novel antioxidant peptides were identified and characterized. The results showed that the peptides (<3 KDa) extracted from low-salt dry-cured ham had higher antioxidant activity. Therefore, the antioxidant peptides in low-salt dry-cured ham were further characterized and the mechanism of their antioxidant activity was investigated. From the five candidate peptides selected, we found DWPDARGIWHND (DD12) to be highly stable, non-sensitizing, and non-toxic with the highest free radical scavenging activity. Molecular docking predicted that DD12 interacted with Keap1 through hydrogen-bond formation and hydrophobic interactions, suggesting that DD12 had good cellular antioxidant activity. DD12 peptide can bind to DPPH• and ABTS•+, resulting in strong free radical scavenging activity. Our findings support the development and application of natural antioxidant peptides in dry-cured ham.

Application effects of NaCl substitute on the fermentation profile of Pixian douban (broad bean paste)

The effects of a reduced-salt substitute (composed of NaCl, sodium gluconate, KCl, L-histidine, and L-lysine) applied in the fermentation of traditional Pixian douban (PXDB) were explored in this study according to sensory quality, physicochemical characteristics, color, colony count, and the contents of free amino acids (FAAs), organic acids, and volatile flavor compounds. The results showed that the PXDB with a 15% salt substitution had the most attractive reddish-brown color, a mellow fragrance, and the lowest total colony count of the three pastes. The fermentation quality of the 15% salt substitute PXDB was superior to that of the control groups, its sensory quality was more readily accepted, and the contents of its amino acid nitrogen, FAAs and organic acids had increased by 0.1050, 0.3290, and 3.9068 mg/g, respectively. Moreover, the concentrations of the main aroma compounds in the PXDB containing the salt substitute were higher than those of the control. These included phenylethanol, 3-methylthiopropanol, isoamyl alcohol, furfural, benzaldehyde, phenylacetaldehyde, nonanal, isoamyl aldehyde, 4-ethylphenol, and, particularly, 2,6-dimethylpyrazine, which had increased as much as 100 times. Correlation analysis showed that Glu, Phe, Tyr, Gly, Leu, Val, Asp, Ile, citric acids, and succinic acids were all positively correlated with the main aroma and contributed to the generation of PXDB's characteristic flavor, and main aroma substances in turn positively influence PXDB flavor sensory attributes. Overall, these results showed the application of the 15% salt substitute during PXDB fermentation improved the quality of the paste and, thus, would benefit the development of reduced-salt PXDB.

TRPC3 deficiency attenuates high salt-induced cardiac hypertrophy by alleviating cardiac mitochondrial dysfunction

Long-term high salt intake leads to cardiac hypertrophy, but the mechanism remains elusive. Transient receptor potential channel, canonical 3(TRPC3), located in mitochondria, regulates mitochondrial calcium and reactive oxygen species(ROS) production. Herein, we investigated whether TRPC3 participates in high salt-induced cardiac hypertrophy by impairing cardiac mitochondrial function. High salt treatment increased the expression of mitochondrial TRPC3 in cardiomyocytes, accompanied by enhanced mitochondrial calcium uptake and elevated ROS production. Inhibition of TRPC3 significantly reduced high salt-induced ROS generation, promoted ATP production by stimulating oxidative phosphorylation, and increased enzyme activity in mitochondria in cardiomyocytes. Additionally, TRPC3 deficiency inhibited high salt-induced cardiac hypertrophy in vivo. A long-term high salt diet increased cardiac mitochondrial TRPC3 expression, elevated expression of cardiac hypertrophic markers atrial natriuretic peptide (ANP),brain natriuretic peptide (BNP) and β-myosin heavy chain (β-MHC) and decreased ATP production and mitochondrial complex I and II enzyme activity in a TRPC3-dependent manner. TRPC3 deficiency antagonises high salt diet-mediated cardiac hypertrophy by ameliorating TRPC3-mediated cardiac mitochondrial dysfunction. TRPC3 may therefore represent a novel target for preventing high salt-induced cardiac damage.

Does gender influence cardiovascular remodeling in C57BL/6J mice fed a high-fat, high-sucrose and high-salt diet?

Animal models are widely used to study the physiopathology of human diseases. However, the influence of gender on modern society diet style-induced cardiovascular disease has not thus far been explored in these models. Thus, this study investigated cardiovascular remodelling in C57BL/6J mice fed a diet rich in saturated fat, sucrose and salt, evaluating gender effect on this process. Male and female C57BL/6J mice were fed AIN93M diet or a modified AIN93M rich in fat, sucrose and salt (HFSS) for 12 weeks. Body mass, water and food intake and cardiovascular remodelling were assessed. The HFSS diet did not lead to body mass gain or glucose metabolism disturbance as assessed by serum glucose, insulin and oral glucose tolerance test. However, female mice on a HFSS diet had increased visceral and subcutaneous adiposity. Only male mice displayed heart hypertrophy. The left ventricle was not hypertrophied in either male or female mice, but its lumen was dilated. Intramyocardial arteries and the thoracic aorta showed media thickening in male mice, but in the female it was only observed in the thoracic aorta. Finally, intramyocardial artery dilation was present in both genders, but not in the aorta. Therefore changes in LV dimensions and arterial remodelling were influenced by both gender and the HFSS diet. In conclusion, male and female C57BL/6J mice suffered cardiovascular remodelling after 12 weeks of HFSS feeding, although they did not develop obesity or diabetes. Sexual dimorphism occurred in response to diet for body adiposity, heart hypertrophy and intramyocardial artery remodelling.

Validity and reliability of the dietary sodium restriction questionnaire in patients with hypertension

The study aimed to evaluate the reliability and the validity of the dietary sodium restriction questionnaire (DSRQ) in patients with hypertension receiving outpatient treatment at a tertiary care university hospital in Southern Brazil. This instrument is composed of three subscales: attitude, subjective norm and perceived behavioral control. A total of 104 patients were included. They were 63.3±8.9 years old and 75% were females. Cronbach's alpha coefficient for the subscales of attitude, subjective norm and perceived behavioral control were 0.75, 0.37 and 0.82, respectively. The PCA with the extraction of three factors explained a total of 53.5% of the variance. The data suggest that the 15-item DSRQ is reliable and has internal consistency of its construct to measure the barriers and the attitudes of hypertensive patients related to dietary sodium restriction and may be useful to improve blood pressure control.

Salt Intakes, Knowledge, and Behavior in Samoa: Monitoring Salt-Consumption Patterns Through the World Health Organization's Surveillance of Noncommunicable Disease Risk Factors (STEPS)

This project measured population salt intake in Samoa by integrating urinary sodium analysis into the World Health Organization's (WHO's) STEPwise approach to surveillance of noncommunicable disease risk factors (STEPS). A subsample of the Samoan Ministry of Health's 2013 STEPS Survey collected 24-hour and spot urine samples and completed questions on salt-related behaviors. Complete urine samples were available for 293 participants. Overall, weighted mean population 24-hour urine excretion of salt was 7.09 g (standard error 0.19) to 7.63 g (standard error 0.27) for men and 6.39 g (standard error 0.14) for women (P=.0014). Salt intake increased with body mass index (P=.0004), and people who added salt at the table had 1.5 g higher salt intakes than those who did not add salt (P=.0422). A total of 70% of the population had urinary excretion values above the 5 g/d cutoff recommended by the WHO. A reduction of 30% (2 g) would reduce average population salt intake to 5 g/d, in line with WHO recommendations. While challenging, integration of salt monitoring into STEPS provides clear logistical and cost benefits and the lessons communicated here can help inform future programs.

Salt, blood pressure and cardiovascular risk: what is the most adequate preventive strategy? A Swiss perspective

Among the various strategies to reduce the incidence of non-communicable diseases reduction of sodium intake in the general population has been recognized as one of the most cost-effective means because of its potential impact on the development of hypertension and cardiovascular diseases. Yet, this strategic health recommendation of the WHO and many other international organizations is far from being universally accepted. Indeed, there are still several unresolved scientific and epidemiological questions that maintain an ongoing debate. Thus what is the adequate low level of sodium intake to recommend to the general population and whether national strategies should be oriented to the overall population or only to higher risk fractions of the population such as salt-sensitive patients are still discussed. In this paper, we shall review the recent results of the literature regarding salt, blood pressure and cardiovascular risk and we present the recommendations recently proposed by a group of experts of Switzerland. The propositions of the participating medical societies are to encourage national health authorities to continue their discussion with the food industry in order to reduce the sodium intake of food products with a target of mean salt intake of 5–6 grams per day in the population. Moreover, all initiatives to increase the information on the effect of salt on health and on the salt content of food are supported.

Salt Reduction Initiatives around the World - A Systematic Review of Progress towards the Global Target

OBJECTIVE

To quantify progress with the initiation of salt reduction strategies around the world in the context of the global target to reduce population salt intake by 30% by 2025.

METHODS

A systematic review of the published and grey literature was supplemented by questionnaires sent to country program leaders. Core characteristics of strategies were extracted and categorised according to a pre-defined framework.

RESULTS

A total of 75 countries now have a national salt reduction strategy, more than double the number reported in a similar review done in 2010. The majority of programs are multifaceted and include industry engagement to reformulate products (n = 61), establishment of sodium content targets for foods (39), consumer education (71), front-of-pack labelling schemes (31), taxation on high-salt foods (3) and interventions in public institutions (54). Legislative action related to salt reduction such as mandatory targets, front of pack labelling, food procurement policies and taxation have been implemented in 33 countries. 12 countries have reported reductions in population salt intake, 19 reduced salt content in foods and 6 improvements in consumer knowledge, attitudes or behaviours relating to salt.

CONCLUSION

The large and increasing number of countries with salt reduction strategies in place is encouraging although activity remains limited in low- and middle-income regions. The absence of a consistent approach to implementation highlights uncertainty about the elements most important to success. Rigorous evaluation of ongoing programs and initiation of salt reduction programs, particularly in low- and middle- income countries, will be vital to achieving the targeted 30% reduction in salt intake.

Adaptation, Update and Validation of the General Nutrition Questionnaire in a Portuguese Adolescent Sample

This article describes the adaptation of the adult Portuguese version of the General Nutrition Knowledge Questionnaire (GNKQ) for adolescents, and its validation. Respondents were 1,315 adolescents, who completed the questionnaire in two phases. A subsample of 73 adolescents was used to measure test-retest reliability. Concurrent validity was tested using a sample of 32 dietetic students. The adapted version showed high internal consistency (Cronbach's alpha = 0.92), test-retest reliability (R = 0.71) and concurrent validity (U = 22766.0; p < .01). Adolescents' nutrition knowledge can now be assessed with a valid and reliable instrument. Future validation works of this or others questionnaires for children and elderly are warranted.

[Cerebrovascular mortality in Portugal: are we overemphasizing hypertension and neglecting atrial fibrillation?]

Cerebrovascular disease has long been the leading cause of death in Portugal. Despite improvements in the treatment of hypertension and the resulting decrease in associated mortality, the progressive aging of the population and increased prevalence of atrial fibrillation have prevented the incidence of stroke from falling as much as desired. The authors review the evidence on the situation in Portugal and propose an intervention plan.

The effect of salt usage behavior on sodium intake and excretion among Korean women

This study was done to explore the effect of Korean women's salt usage behavior on their sodium intake and excretion according to aging. Dietary sodium intake and salt usage behavior were analyzed to compare the difference between young and middle-aged women. One hundred fifty six young women and 77 middle-aged women without hypertension or any current medication were recruited. Body mass index, waist hip ratio, blood pressure were measured from each subject. Salt usage behaviors were surveyed with questionnaire, sodium intake with 24-hr recall method, and sodium excretion with spot urine. Middle-aged women were more obese than young women according to body mass index and waist hip ratio. Blood pressure was significantly higher for the middle-aged. Young women consumed more fats and middle-aged women more carbohydrates. Middle-aged women consumed more sodium and potassium, and excreted more sodium. Among questionnaire items, kimchi, soup or pot stew, or salted vegetables were found to be related with high sodium diet. Salted vegetables and salted nuts and potato chips were significantly correlated with young women's high sodium diet, while soy sauce on fried food, kimchi, salted vegetables accounted for middle-aged women's high sodium diet. With these results, we concluded that middle-aged women consumed more carbohydrates, less fat, and more sodium and potassium than young women. Middle-aged women frequently choose kimchi, soup or pot stew, or salted vegetables, and they contribute to high sodium intake. We recommend to choose low-salt kimchi, less soup or pot stew, and more fresh vegetables for lower sodium diet.

Sodium recommendations for special populations and the resulting implications

Based on the most recent Dietary Guidelines for Americans, sodium recommendations are set at 2,300 mg for the general population and 1,500 mg for special populations. However, sodium intake among adults has been shown to be much higher than this; on average 3,436 mg. The Centers for Disease Control and Prevention notes that special populations (those with hypertension, African Americans, and those 40 years of age and older) make up 70% of adults in the United States. Excess sodium in the diet has been shown to contribute to problems such as blood pressure abnormalities, kidney function problems, and congestive heart failure, which account for a large sum of health care costs in the United States. The purpose of this review and accompanying three case studies was to explore if adherence to the sodium recommendations for special populations is feasible. Current literature shows that while a food industry-wide sodium reduction would help reduce overall sodium intake, adherence to low-sodium diets is difficult for the majority of individuals. Three case studies were completed which looked at subjects with a sodium recommendation of 1,500 mg. None of the participants met the recommendation, were aware of their daily sodium intake or knew how much they should be consuming. The snapshot provided by these case studies suggests further research is warranted. Because of the current state of sodium in the American diet, a combination of personal interventions coupled with widespread industry sodium reduction would be the most beneficial way to reduce dietary sodium for most individuals.

WASH-world action on salt and health

There is overwhelming evidence that our current high-salt intake is the major factor increasing blood pressure (BP) and, thereby, a major cause of cardiovascular disease and kidney disease worldwide. A reduction in salt intake to the recommended level of <5-6 g/day is very beneficial, and could prevent millions of deaths each year and make major savings for healthcare services. Several countries, e.g., Finland and the UK, have already reduced the amount of salt being consumed by a combined policy of getting the food industry to decrease the amount of salt added to foods, clear labelling on food products, and increasing public awareness of the harmful effects of salt on health. Many other developed countries, e.g., Australia, Canada, and the US, are also stepping up their activities. The major challenge now is to spread this out worldwide, particularly to developing countries where ≈80% of global BP-related disease burden occurs. In many developing countries, most of the salt consumed comes from salt added during cooking or from sauces; therefore, public health campaigns are needed to encourage consumers to use less salt. A modest reduction in salt intake across the whole population will result in major improvements in public health and have huge economic benefits in all countries around the world. World Action on Salt and Health (WASH) is a coalition of health professionals from different countries who know very well the harm of high BP and has a major role in implementing changes in their own countries. We welcome nephrologists to join (http://www.worldactiononsalt.com).