High salt intake: detrimental not only for blood pressure, but also for bone health?

A review of the world's salt reduction policies and strategies - preparing for the upcoming year 2025

Excessive consumption of dietary sodium is a significant contributor to non-communicable diseases, including hypertension and cardiovascular disease. There is now a global consensus that regulating salt intake is among the most cost-effective measures for enhancing public health. More than half of the countries worldwide have implemented multiple strategies to decrease salt consumption. Nevertheless, a report on sodium intake reduction published by the World Health Organization revealed that the world is off-track to meet its targeted reduction of 30% by 2025. The global situation regarding salt reduction remains concerning. This review will center on domestic and international salt reduction policies, as well as diverse strategies, given the detrimental effects of excessive dietary salt intake and the existing global salt intake scenario. Besides, we used visualization software to analyze the literature related to salt reduction research in the last five years to explore the research hotspots in this field. Our objective is to enhance public awareness regarding the imperative of reducing salt intake and promoting the active implementation of diverse salt reduction policies.

High Salt Diet Impairs Male Fertility in Mice via Modulating the Skeletal Homeostasis

Male reproductive functions and bone health are both adversely affected by the high salt diet (HSD). Nevertheless, the underlying mechanism via which it alters the sperm function remains largely unknown. This study examines the mechanism by which HSD affects male fertility by impairing bone health. For investigating the same, male BALB/c mice were categorized into three groups-HSD group (fed with 4% NaCl), a low salt diet (LSD) group (fed with 0.4% NaCl), and a control group (fed with a normal diet) for 6 weeks and thereafter assessed for various sperm parameters, bone turnover markers, and testosterone levels. Furthermore, the quantitative assessment of testosterone biosynthesis enzymes was performed. Interestingly, we observed that mice fed with HSD showed significant alterations in sperm parameters-motility, count, and vitality, including morphological changes compared to both the LSD and the control groups. In addition, serum analysis showed an increase in bone resorption markers and a decrease in bone formation markers in the HSD group (p < 0.05). Further, HSD caused a decrease in the testosterone level and mRNA expression of testosterone biosynthesis enzymes. Importantly, a significant decrease in bone formation marker osteocalcin (OC) was observed to coincide with the dip in testosterone level in the HSD group. Given that OC plays a key role in maintaining male fertility, the above findings suggest that a decrease in OC levels may affect the testosterone biosynthesis pathway, reducing testosterone hormone secretion and thereby resulting in decreased spermatogenesis. The study for the first time delineates and bridges the mechanism of HSD-mediated bone loss (results in a deficiency of OC) with decreased testosterone biosynthesis and thus impaired male fertility.

Nutrition, Physical Activity, and Dietary Supplementation to Prevent Bone Mineral Density Loss: A Food Pyramid

Bone is a nutritionally modulated tissue. Given this background, aim of this review is to evaluate the latest data regarding ideal dietary approach in order to reduce bone mineral density loss and to construct a food pyramid that allows osteopenia/osteoporosis patients to easily figure out what to eat. The pyramid shows that carbohydrates should be consumed every day (3 portions of whole grains), together with fruits and vegetables (5 portions; orange-colored fruits and vegetables and green leafy vegetables are to be preferred), light yogurt (125 mL), skim milk (200 mL,) extra virgin olive oil (almost 20 mg/day), and calcium water (almost 1 l/day); weekly portions should include fish (4 portions), white meat (3 portions), legumes (2 portions), eggs (2 portions), cheeses (2 portions), and red or processed meats (once/week). At the top of the pyramid, there are two pennants: one green means that osteopenia/osteoporosis subjects need some personalized supplementation (if daily requirements cannot be satisfied through diet, calcium, vitamin D, boron, omega 3, and isoflavones supplementation could be an effective strategy with a great benefit/cost ratio), and one red means that there are some foods that are banned (salt, sugar, inorganic phosphate additives). Finally, three to four times per week of 30-40 min of aerobic and resistance exercises must be performed.

A Review Study of a Green Diet and Healthy Ageing

Nowadays people are living longer, and there has been a substantial growth in the global elderly population in the past decades. While life expectancy is increasing, there are growing concerns towards the heavy financial and social burdens related to chronic diseases among the elderly. These have been critical health care issues, and healthy ageing is considered a top priority in public health. Diet and eating habits are crucial factors contributing to healthy ageing. These important aspects have attracted much attention in health research, particularly in consideration of the causes and management of chronic conditions which affect most elder adults in the world. Recently, a growing number of investigations have reported significant findings on the association of reduction in the risks of chronic non-communicable diseases with plant-based diets. Meanwhile, there have been worldwide initiatives and programmes implemented for reduction of salt intake. A green diet, which emphasises the consumption of a diet rich in plant foods with minimal portions of red or processed meat and reduced salt intake, is advocated with due consideration to the importance of sustainable environment and healthy ageing. This paper highlights a brief review of the recent advance of knowledge in diet and health, its effects on the elderly and the significance of a green diet on healthy ageing. Implications for a green diet and recommendations for future research are also discussed.

Spironolactone reduces biochemical markers of bone turnover in postmenopausal women with primary aldosteronism

CONTEXT

Primary aldosteronism (PA) is the most frequent form of endocrine hypertension. Besides its deleterious impact on cardiovascular target organ damage, PA is considered to cause osteoporosis.

PATIENTS AND METHODS

We assessed bone turnover in a subset of 36 postmenopausal women with PA. 18 patients had unilateral PA and were treated by adrenalectomy, whereas 18 patients had bilateral PA and received mineralocorticoid receptor antagonist (MRA) therapy respectively. 18 age- and BMI-matched females served as controls. To estimate bone remodeling, we measured the bone turnover markers intact procollagen 1 N-terminal propeptide, bone alkaline phosphatase, osteocalcin and tartrate resistant acid phosphatase 5b in plasma by chemiluminescent immunoassays at time of diagnosis and one year after initiation of treatment.

STUDY DESIGN

Observational longitudinal cohort study.

SETTING

Tertiary care hospital.

RESULTS

Compared with controls, patients with PA had mildly elevated osteocalcin at baseline (p = 0.013), while the other bone markers were comparable between both groups. There were no differences between the unilateral and the bilateral PA subgroup. One year after initiation of MRA treatment with spironolactone bone resorption and bone formation markers had significantly decreased in patients with bilateral PA. In contrast, patients adrenalectomized because of unilateral PA showed no significant change of bone turnover markers.

CONCLUSION

This study shows that aldosterone excess in postmenopausal women with PA is not associated with a relevant increase of bone turnover markers at baseline. However, we observed a significant decrease of bone markers in patients treated with spironolactone, but not in patients treated by adrenalectomy.

Increased urinary sodium excretion is associated with systolic blood pressure in first degree relatives of hypertensive patients in Ibadan, Southwestern Nigeria

INTRODUCTION

Understanding the risk factors of hypertension has led to a better understanding of the pathogenesis, prevention and reduction in morbidity of hypertension. It is well known that offsprings of hypertensive parents have an increased risk of developing hypertension. It is therefore necessary to explore the physiological differences between normotensive patients with and without a positive family history of hypertension with respect to their urinary excretion of sodium.

METHODS

This study was carried out at the University College Hospital, Ibadan Nigeria, to determine if normotensive patients with a positive family history of hypertension are different with respect to their urinary excretion of electrolytes and blood pressure. It examined the relationship between 24-hour urinary excretion of sodium, chloride and potassium, urea and creatinine and blood pressure in subjects with and without family history of hypertension. It was a case-control study of sixty-two subjects: normotensive patients' first degree relatives of primary hypertensive patients and normotensive patients without positive family history.

RESULTS

The mean (SD) systolic blood pressures for subjects with and without family history of hypertension were significantly different: 120.0(22.25) and 105.0(17.50) respectively, (p=0.001). The mean arterial blood pressures were significantly different: 86.4(10.2) mmHg and 80.1(8.1) mmHg respectively (p=0.010). The mean (SD) 24-hour urinary excretion of sodium for normotensive patients with and without positive family history of hypertension were 180.5 (45.50) mEq/L, and 156.0(36.25) mEq/L respectively. Systolic blood pressure and 24-hour urinary excretion of sodium was also higher in normotensive subjects with a positive family history of hypertension.

CONCLUSION

Systolic blood pressure and twenty-four hour urinary excretion of sodium were higher in normotensive subjects with a positive family history of hypertension than in those without a family history of hypertension.

Biogenic Amines and Predictive Models of Quality of Rainbow Trout ( Oncorhynchus mykiss ) Fillets during Storage

To estimate biogenic amines and changes in quality of rainbow trout ( Oncorhynchus mykiss ) fillets at different temperatures, we determined the sensory attributes, total volatile basic nitrogen (TVB-N), total viable counts (TVC), and biogenic amines (BAs) of samples that were untreated (CK) or dry cured with 1.8% salt (T). There was no significant difference between CK and T samples in terms of TVB-N, TVC, and BAs. TVB-N and TVC increased significantly (P < 0.05) with storage time at 3, 9, and 15°C. Putrescine (PUT) and cadaverine (CAD) increased significantly (P < 0.05) at -3, 3, 9, and 15°C during storage. Histamine formed more easily when storage temperatures were higher. The kinetic models of sensory scores for TVB-N, TVC, PUT, CAD, and the sum of PUT and CAD (PUT+CAD) in T samples versus storage time and temperature were developed based on the Arrhenius equation. High regression coefficients (R² > 0.9) indicated the acceptability of the kinetic model for predicting changes in the quality of the rainbow trout fillets. Relative errors between predicted and experimental values of TVB-N, TVC, and PUT+CAD were all within 10% except for TVB-N on day 6. The prediction model based on TVB-N, TVC, and PUT+CAD can be applied to evaluate changes in quality of rainbow trout fillets from -3 to 15°C (270 to 288 K).