Supplementary dietary calcium stimulates faecal fat and bile acid excretion, but does not protect against obesity and insulin resistance in C57BL/6J mice

Review Article on Molecular Mechanism of Regulation of Hypertension by Macro-elements (Na, K, Ca and Mg), Micro-elements/Trace Metals (Zn and Cu) and Toxic Elements (Pb and As)

Hypertension (HT) is a medical condition arising due to increase in blood pressure (BP) prevalent worldwide. The balanced dietary intakes of macro-elements and micro-elements including Na, K, Ca, Mg, Zn, and Cu have been described to maintain BP in humans by regulating the osmolarity of blood, cells/tissues, prevention of generation of oxidative and nitrosative stress (OANS), and endothelial damage through their functioning as important components of renin-angiotensin-aldosterone system (RAAS), antioxidant enzyme defense system, and maintenance of blood vascular-endothelial and vascular smooth muscle cell (VSMC) functions. However, inadequate/excess dietary intakes of Na/K, Ca/Mg, and Zn/Cu along with higher Pb and As exposures recognized to induce HT through common mechanisms including the followings: endothelial dysfunctions due to impairment of vasodilatation, increased vasoconstriction and arterial stiffness, blood clotting, inflammation, modification of sympathetic activity and higher catecholamine release, increased peripheral vascular resistance, and cardiac output; increased OANS due to reduced and elevated activities of extracellular superoxide dismutase and NAD(P)H oxidase, less nitric oxide bioavailability, decrease in cGMP and guanylate cyclase activity, increase in intracellular Ca2+ ions in VSMCs, and higher pro-inflammatory cytokines; higher parathyroid and calcitriol hormones; activation/suppression of RAAS resulting imbalance in blood Na+, K+, and water regulated by renin, angiotensin II, and aldosterone through affecting natriuresis/kaliuresis/diuresis; elevation in serum cholesterol and LDL cholesterol, decrease in HDL cholesterol due to defect in lipoprotein metabolism. The present study recommends the need to review simple dietary mineral intervention studies/supplementation trials before keeping their individual dietary excess intakes/exposures in consideration because their interactions lead to elevation and fall of their concentrations in body affecting onset of HT.

Dairy products and constituents: a review of their effects on obesity and related metabolic diseases

Obesity has become a global public health problem that seriously affects the quality of life. As an important part of human diet, dairy products contain a large number of nutrients that are essential for maintaining human health, such as proteins, peptides, lipids, vitamins, and minerals. A growing number of epidemiological investigations provide strong evidence on dairy interventions for weight loss in overweight/obese populations. Therefore, this paper outlines the relationship between the consumption of different dairy products and obesity and related metabolic diseases. In addition, we dive into the mechanisms related to the regulation of glucose and lipid metabolism by functional components in dairy products and the interaction with gut microbes. Lastly, the role of dairy products on obesity of children and adolescents is revisited. We conclude that whole dairy products exert more beneficial effect than single milk constituent on alleviating obesity and that dairy matrix has important implications for metabolic health.

The Eeffect of Metformin Combined with Calcium-Vitamin D3 Against Diet-Induced Nonalcoholic Fatty Liver Disease

Purpose: Metformin is one of the most popular drugs tested against nonalcoholic fatty liver disease (NAFLD). The present study aimed to investigate whether calcium-vitamin D₃ cosupplementation will intensify the effect of metformin on the prevention of high-fat, high-fructose (HFFr) diet-induced hepatic steatosis.

Methods: Male wistar rats (210±16 g) were assigned into the following seven groups: a Control group to receive a standard chow and six HFFr-fed groups to receive diets containing either normal (0.5% calcium and 1000 IU/kg vitamin D₃) or high amount of calcium and vitamin D₃ (2.4% calcium and 10000 IU/kg vitamin D₃) (CaD), in combination with gastric gavage administration of either saline or 25 or 200 mg/kg body weight/day metformin. After 60 days, rats were assessed with respect to their anthropometric, metabolic and hepatic parameters, as well as their hepatic AMP-activated protein kinase (AMPK) phosphorylation.

Results: Metformin and CaD, either alone or in combination, caused a significant reduction in HFFr diet-induced high serum aspartate aminotransferase (AST), hepatic steatosis and lipid accumulation without effect on insulin resistance and AMPK phosphorylation. In addition, slightly (and non-significantly) better effects of the combination in ameliorating steatosis and hepatic cholesterol content were observed.

Conclusion: Taken together, our results suggest that metformin and CaD could protect against the onset of HFFr diet-induced NAFLD in an insulin and AMPK-independent manner, without any marked additional benefits of their combination.

Flavonoids, Dairy Foods, and Cardiovascular and Metabolic Health: A Review of Emerging Biologic Pathways

A growing body of nutritional science highlights the complex mechanisms and pleiotropic pathways of cardiometabolic effects of different foods. Among these, some of the most exciting advances are occurring in the area of flavonoids, bioactive phytochemicals found in plant foods; and in the area of dairy, including milk, yogurt, and cheese. Many of the relevant ingredients and mechanistic pathways are now being clarified, shedding new light on both the ingredients and the pathways for how diet influences health and well-being. Flavonoids, for example, have effects on skeletal muscle, adipocytes, liver, and pancreas, and myocardial, renal, and immune cells, for instance, related to 5'-monophosphate-activated protein kinase phosphorylation, endothelial NO synthase activation, and suppression of NF-κB (nuclear factor-κB) and TLR4 (toll-like receptor 4). Effects of dairy are similarly complex and may be mediated by specific amino acids, medium-chain and odd-chain saturated fats, unsaturated fats, branched-chain fats, natural trans fats, probiotics, vitamin K1/K2, and calcium, as well as by processing such as fermentation and homogenization. These characteristics of dairy foods influence diverse pathways including related to mammalian target of rapamycin, silent information regulator transcript-1, angiotensin-converting enzyme, peroxisome proliferator-activated receptors, osteocalcin, matrix glutamate protein, hepatic de novo lipogenesis, hepatic and adipose fatty acid oxidation and inflammation, and gut microbiome interactions such as intestinal integrity and endotoxemia. The complexity of these emerging pathways and corresponding biological responses highlights the rapid advances in nutritional science and the continued need to generate robust empirical evidence on the mechanistic and clinical effects of specific foods.

Evaluation of calcium supplementation with algae (Lithothamnion muelleri) on metabolic and inflammatory parameters in mice fed a high refined carbohydrate-containing diet

The aim of the present study was to evaluate the potential of calcium supplementation from Lithothamnium muelleri algae on metabolic and inflammatory parameters in mice with increased adiposity. Male mice were fed and divided during 8 weeks in: control (C), a high refined carbohydrate-containing diet (HC), HC diet supplemented with 1% of Lithothamnion muelleri algae (HC + A) and HC diet supplemented with 0.9% calcium carbonate (HC + C). Animals fed HC diet had increased body weight gain and adiposity, serum glucose and cholesterol, glucose intolerance and decreased insulin sensitivity, compared to control diet. However, the HC + A and HC + C groups did not prevent these aspects and were not able to change the CD14 + cells population in adipose tissue of animals fed HC diet. Calcium supplementation with Lithothamnium muelleri algae and calcium carbonate had no protective effect against the development of adiposity, metabolic and inflammatory alterations induced by HC diet.

Daily calcium intake and its relation to blood pressure, blood lipids, and oxidative stress biomarkers in hypertensive and normotensive subjects

Several studies revealed that low calcium intake is related to high prevalence of cardiovascular diseases such as hypertension. The prevalence of hypertension is high in Koreans along with their low dietary calcium consumption. Thus, the aim of this study was to evaluate the status of calcium intake between the hypertension and normotension groups and to investigate the correlation between dietary calcium intake and blood pressure, blood lipid parameters, and blood/urine oxidative stress indices. A total of 166 adult subjects participated in this study and were assigned to one of two study groups: a hypertension group (n = 83) who had 140 mmHg or higher in systolic blood pressure (SBP) or 90 mmHg or higher in diastolic blood pressure (DBP), and an age- and sex-matched normotension group (n = 83, 120 mmHg or less SBP and 80 mmHg or less DBP). The hypertension group consumed 360.5 mg calcium per day, which was lower than that of the normotension group (429.9 mg) but not showing significant difference. In the hypertension group, DBP had a significant negative correlation with plant calcium (P < 0.01) after adjusting for age, gender, body mass index (BMI), and energy intake. In the normotension group, total calcium and animal calcium intake were significantly and positively correlated with serum triglycerides. No significant relationship was found between calcium intake and blood/urine oxidative stress indices in both groups. Overall, these data suggest reconsideration of food sources for calcium consumption in management of the blood pressure or blood lipid profiles in both hypertensive and normotensive subjects.

The framingham risk score, diet, and inflammatory markers in Korean men with metabolic syndrome

The Framingham risk score (FRS) has been used to assess the risk of a cardiovascular event and to identify patients for risk factor modifications. Therefore, the purpose of this study was to evaluate the relationship of the FRS with dietary intake and inflammatory biomarkers. We conducted a cross-sectional study of 180 men (49.2 ± 10.2 years) with MS. Serum levels of high sensitive C-reactive protein (hs-CRP), interleukin-6 (IL-6), and adiponectin were examined. Participants were asked to complete the food frequency questionnaire (FFQ) using the previous 1 year as a reference point. The absolute cardiovascular disease (CVD) risk percentage over 10 years was calculated to estimate the FRS, which was classified as low risk (< 10%), intermediate risk (10-20%), and high risk (> 20%). Mean intake of polyunsaturated fatty acids was lower in subjects who had > 20% FRS than in subjects who had < 10% FRS (3.7 ± 1.9 g/day vs. 4.7 ± 1.9 g/day; P < 0.05). Significant differences in the Index of Nutritional Quality of protein, phosphorus, iron, vitamin A, vitamin B₁, niacin, vitamin B₆, and vitamin C were observed between the > 20% FRS group and the < 10% FRS group (P < 0.05). IL-6 concentrations were significantly lower in subjects with a < 10% FRS than in subjects who were 10-20% FRS or > 20% FRS (0.91 ± 0.26 vs. 1.48 ± 033 vs. 2.72 ± 0.57 pg/mL, respectively; P < 0.05). IL-6 and dietary intake of polyunsaturated fatty acids together explained 6.6% of the variation in FRS levels in a stepwise multiple regression model. Our results provide some evidence that dietary intake in the higher CVD risk group was inferior to that in the lower risk group and that dietary fat intake and IL-6 were associated with FRS and MS in Korean men.

Calcium and vitamin D in obesity

New and more effective nutritional measures are urgently needed for the prevention of obesity. The role of Ca and vitamin D in obesity has been recently implicated. Low Ca intake and low vitamin D status have been linked with an increased risk of obesity in epidemiological studies; however, clinical intervention trials designed to test this association have produced controversial results. The suggested anti-obesity mechanisms of Ca and vitamin D include the regulation of adipocyte death (apoptosis), adipogenesis and lipid metabolism. Dietary Ca has been also shown to increase faecal fat excretion. The potential role of Ca and vitamin D in shifting energy balance towards a more negative state is an area of considerable interest. Ultimately, a review of recent research findings does not allow the reaching of a definitive conclusion that increasing Ca intake and rising vitamin D status will influence fat mass and body weight or decrease the risk of obesity and overweight.