The effect of whole grape products on blood pressure and vascular function: A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND AND AIMS: Grape consumption-associated improvements in cardiovascular health have received significant attention over the last few years; however, major gaps have remained in the meta-evidence related to this topic. This systematic review and meta-analysis of randomized controlled trials (RCTs) was performed to explore the effect of whole grapes and its products on blood pressure, endothelial function, heart rate, and pulse rate. METHODS AND RESULTS: Four database (PubMed, Scopus, Web of Sciences, and the Cochrane Library) were searched until the 14th of January 2022. The pooled effect size of interested outcomes was calculated using the random-effects model. Thirty eligible RCTs were identified. Pooled results indicated that compared to the control group, consumption of grape products significantly decreased systolic blood pressure (SBP) (WMD = -3.17 mmHg; 95% CI: -5.36, -0.99 mmHg; P = 0.004; I2 = 64%; P-heterogeneity<0.001); while, vascular cell adhesion molecule-1 (VCAM-1) increased (WMD = 34.11 ng/ml; 95% CI: 0.98, 67.25 ng/ml; P = 0.04; I2 = 2%; P-heterogeneity = 0.4). Although, the certainty of evidence was low and very low, respectively. No significant effect was observed on diastolic blood pressure, endothelial function, heart rate, pulse rate, and soluble intercellular adhesion molecule-1 (sICAM-1). In a subgroup analysis, consumption of whole grape products (raisin and grape powder) induced a significant decrease in SBP (WMD = -2.69 mmHg; 95% CI: -4.81, -0.57; P = 0.01; I2 = 18.1%; P-heterogeneity < 0.001), while grape juice did not. CONCLUSION: The low certainty of evidence from RCTs revealed that consumption of grape products, especially in whole forms, resulted in a small reduction of SBP but did not influence other markers of cardiovascular health. PROSPERO REGISTRATION CODE: CRD42022379231.

Food and nutrition literacy: a predictor for diet quality and nutrient density among late adolescents.

BACKGROUND: Evidence regarding an individual`s food and nutrition literacy (FNL), and its impact on dietary behaviours, could guide the development of more effective interventions. This study sought to examine the association between FNL and its components with diet quality and nutrient density among Iranian senior highschool students. METHODS: In this cross-sectional study, 755 senior high school students were recruited from high schools in Tehran, Iran. FNL was assessed using the Food and Nutrition Literacy Assessment Tool (FNLAT), a selfadministered questionnaire which has been locally designed and validated. Dietary assessment was performed by obtaining two 24-hour dietary recalls. Healthy Eating Index-2010 (HEI-2010) and nutrient-rich food index 9.3 (NRF9.3) were calculated to evaluate diet quality. Socioeconomic status, anthropometric measures, and the health status of participants were also assessed. RESULTS: Higher FNL score was significantly correlated with higher HEI-2010 (ß = 0.167, p < 0.001) and NRF9.3 (ß = 0.145, p < 0.001) scores. Subgroup analysis indicated that these associations were significant only among males, but not females. Regarding components of FNL, skill dimension of FNL was a stronger predictor for HEI- 2010 (ß = 0.174, p < 0.001) and NRF9.3 (ß = 0.153, p < 0.001) than knowledge (ß = 0.083, p = 0.054 for HEI-2010 and ß = 0.107, p = 0.01 for NRF9.3). CONCLUSIONS: FNL may be a significant predictor of diet quality and nutrient density among late adolescents. To improve the effectiveness of food and nutrition education, emphasis must be placed on skill development.

Effects of probiotic/synbiotic supplementation on body weight in patients with diabetes: a systematic review and meta-analyses of randomized-controlled trials.

OBJECTIVE: The aim of the present study was to assess the effect of probiotic/synbiotic supplementation on anthropometric measures in adults with diabetes, independent of body weight. METHODS: PubMed, Scopus, Web of Sciences and the Cochrane Library were searched for randomized controlled trials (RCTs) up until December 14, 2022. The effect sizes were pooled using an inverse-variance random-effects model. The methodological quality of studies as well as the quality of evidence was assessed using standard tools. RESULTS: Thirty-two RCTs met the established inclusion criteria. Overall, compared with the respective control groups, probiotic/synbiotic supplementation resulted in a significant reduction in body weight (weighted mean difference [WMD]: -0.50 kg; 95% CI: -0.83, -0.17; I2 = 79.8%, n = 27 studies]), body mass index (WMD: -0.24 kg/m2; 95% CI: -0.39, -0.09; I2 = 85.7%, n = 30 studies), and waist circumference (WMD: -0.90 cm; 95% CI: -1.13, -0.52; I2 = 0%, n = 11 studies). However, hip circumference and waist to hip ratio were not significantly improved. CONCLUSIONS: Our analysis revealed that probiotic/synbiotic supplementation may assist with weight management in patients with diabetes, especially when consumed at higher doses, in younger adults, and in participants with obesity. However, more studies are needed to elucidate the anti-obesity effects of specific strains of probiotics/synbiotics.

Oral vitamin D supplementation and body weight in children and adolescents: a systematic review and meta-analysis of randomized controlled trials.

This study was designed to ascertain whether oral vitamin D supplementation (oral supplementation and fortified foods) is associated with changes in body weight measures in children and adolescents, using a systematic review and meta-analysis of randomized controlled trials (RCTs). PubMed, Scopus, Cochrane, and Web of Science databases were searched from inception to October 28, 2022. The mean difference and corresponding 95% confidence interval (CI) of interested outcomes were pooled using a random-effects model. Twenty-one RCTs were included in the meta-analysis, and the results showed a significant decrease in body mass index (BMI) following vitamin D supplementation in children and adolescents (n = 9 studies, 1029 participants; weighted mean difference: - 0.43 kg/m2, 95% CI: - 0.79, - 0.08; P = 0.02; I2 = 58.5%). Overall, oral vitamin D supplementation had no significant effect on body weight and other anthropometric indices, including fat mass, lean mass, waist circumference, BMI Z-score, and height. Although results of body weight changed to significant after sensitivity analysis (WMD = 0.39 kg, 95% CI = 0.01, 0.78; P = 0.04; I2 = 0%, P-heterogeneity = 0.71), we also found significant weight gain in healthy pediatric population, and when the dose of vitamin D supplementation was up to 600 IU/day, the certainty of evidence was very low for weight, moderate for height and BMI, and low for the remaining outcomes. CONCLUSION: Our results suggest that vitamin D supplementation may lead to a statistically significant weight gain in children and adolescents, while BMI was reduced. Although no significant change was observed in height, it seems vitamin D supplementation may elicit these changes by increasing skeletal growth; however, this remains to be verified. Further high-quality RCTs, with longer duration and larger sample sizes, are needed to yield more certain evidence in this regard. WHAT IS KNOWN: • Available evidence indicates an inverse association between body weight/fat mass and vitamin D status in children and adolescents; however, findings regarding the effect of vitamin D supplementation on anthropometric measurements in children are controversial. WHAT IS NEW: • Our results showed a significant decrease in BMI following vitamin D supplementation in children. • A significant weight gain also was observed after sensitivity analysis, and in healthy pediatric population, and when the dose of vitamin D supplementation was up to 600 IU/day.

Riboflavin is an antioxidant: a review update.

Aerobic organisms need antioxidant defense systems to deal with free radicals which either are produced during aerobic respiration or may have an external origin. Oxidative stress, which is resulted from an imbalance between the production of free radicals and the ability of antioxidant defense mechanism to deactivate them, is involved in the development of many chronic diseases such as cancer, diabetes, CVD and some neurodegenerative diseases. Reinforcing the antioxidant potential of the body has been considered as a strategy that could prevent and manage such conditions. In the previous review article published by British Journal of Nutrition, in 2014, for the first time, we concluded that riboflavin could alleviate oxidative stress. Although riboflavin can serve as a prooxidant when exposed to ultraviolet irradiation, the literature is replete with studies that support its antioxidant properties. Furthermore, recent evidence suggests that riboflavin may have a therapeutic potential in many conditions in which oxidative stress is involved, although the therapeutic efficacy of riboflavin as an antioxidant requires further study under conditions of wellness and clinical disease.

Food and nutrition literacy status and its correlates in Iranian senior high-school students.

BACKGROUND: Planning interventions to promote food and nutrition literacy (FNL) require a better understanding of the FNL status of the target group and its correlates. AIMS: This study aimed to examine the FNL status and its determinants in Iranian senior high-school students. METHODS: In this cross-sectional study, FNL and its components (food and nutrition knowledge, functional skills, interactive skills, advocacy, critical analysis of information, and food label reading skill) were evaluated by a locally designed and validated, self-administered questionnaire. Besides, socioeconomic, demographic, anthropometric measures, as well as academic performance of 626 senior high-school students were assessed. RESULTS: The mean ± SD of the total FNL score (within potential range of 0 to 100) was 52.1 ± 10.96, which is below the minimum adequate level of 60. The probability of high FNL knowledge score was significantly higher among students who majored in Natural Sciences (OR = 1.73, CI = 1.09-2.75), had better school performance (OR = 1.13, CI = 1.06-1.20) and higher SES score (OR = 1.20, CI = 1.01-1.44). The score for food label reading was significantly lower in girls (OR = 0.45, CI = 0.31-0.67), while those who had a family member with the nutrition-related disease were more likely to have a higher score of food label reading skill (OR = 1.48, CI = 1.01-1.64). CONCLUSION: The level of FNL in senior high-school students in Tehran was relatively low. These findings have key messages for the education system and curriculum designers to have more consideration for food and nutrition-related knowledge and skills in schools.

Development and Validation of Food and Nutrition Literacy Assessment Tool for Iranian High-school Graduates and Youth.

BACKGROUND: Food and nutrition literacy (FNL) is an emerging concept that emphasizes not only on personal knowledge, but food and nutrition skills about. This study aimed to develop and validate a food and nutrition literacy assessment tool (FNLAT) for youth and high-school graduates in Iran. METHODS: The study protocol included the following steps: First, FNL components for Iranian high-school graduates and youth were identified through literature review and interviews with experts. Delphi method was used in order to achieve consensus about FNL components. Then, the questionnaire items were generated, and its content and face validity were assessed. Construct validity of the questionnaire was evaluated through applying principal component analysis (PCA) and confirmatory factor analyses (CFA) in the next step. Finally, reliability of the FNLAT was assessed by calculating Cronbach's Alpha and evaluating test-retest reliability. RESULTS: A 104-item questionnaire was developed. S-CVI was ≥90 which confirmed content validity of the questionnaire. PCA suggested that it was constructed of 6 factors, one in knowledge domain (food and nutrition knowledge) and five in skill domain (functional skills, interactive skills, advocacy, critical analysis of information, and food label reading skills). On the basis of CFA, the fit indices of the model had acceptable fit and confirmed construct validity of the FNLAT (X 2/df = 1.58, RMSEA = 0.041; P = 1.00, RMR = 0.034, GFI = 0.79). The values of Cronbach's Alpha and intraclass correlation coefficient (ICC) confirmed internal consistency and time stability of the FNLAT and its subscales. CONCLUSIONS: The developed FNLAT is a valid and reliable tool to assess FNL in Iranian late adolescents and youth.

Riboflavin in Human Health: A Review of Current Evidences.

Riboflavin is a water-soluble vitamin, which was initially isolated from milk. There are two coenzyme forms of riboflavin, flavin mononucleotide and flavin adenine dinucleotide, in which riboflavin plays important roles in the enzymatic reactions. Riboflavin is found in a wide variety of animal and plant foods. Meat and dairy products are the major contributors of riboflavin dietary intake. In this chapter, the latest evidence on the relationship between riboflavin status and specific health risks will be reviewed. Also, some of the mechanisms by which riboflavin exerts its roles will be discussed. The evidence accrued suggests that riboflavin is an antioxidant nutrient which may prevent lipid peroxidation and reperfusion oxidative injury. Moreover, riboflavin deficiency may increase the risk of some cancers. Riboflavin may also exert a neuroprotective effects in some neurological disorders (e.g., Parkinson disease, migraine, and multiple sclerosis) through its role in some pathways that are hypothesized to be impaired in neurological disorders such as antioxidation, myelin formation, mitochondrial function, and iron metabolism.

Riboflavin (vitamin B2) and oxidative stress: a review.

Oxidative stress is involved in the development of many chronic diseases. One of the main factors involved in oxidative stress reduction is increased antioxidant potential. Some nutrients such as vitamin C, vitamin E and carotenoids are known to act as antioxidants; however, riboflavin is one of the neglected antioxidant nutrients that may have an antioxidant action independently or as a component of the glutathione redox cycle. Herein, studies that have examined the antioxidant properties of riboflavin and its effect on oxidative stress reduction are reviewed. The results of the reviewed studies confirm the antioxidant nature of riboflavin and indicate that this vitamin can protect the body against oxidative stress, especially lipid peroxidation and reperfusion oxidative injury. The mechanisms by which riboflavin protects the body against oxidative stress may be attributed to the glutathione redox cycle and also to other possible mechanisms such as the conversion of reduced riboflavin to the oxidised form.