The association between dietary inflammatory index, muscle strength, muscle endurance, and body composition in Iranian adults.

PURPOSE: Dietary factors may modulate inflammation status which contributed to the various chronic diseases like sarcopenia. Therefore, we aimed to examine the association of dietary inflammatory index (DII) and muscle strength (MS), muscle endurance (ME), and body composition. METHODS: This cross-sectional study was conducted in 270 adults living in Tehran, Iran. The DII was calculated using a validated food frequency questionnaire. Body composition (fat-free mass (FFM), fat mass (FM), percent body fat (PBF), skeletal muscle mass (SMM)) was measured using body composition analyzer. Anthropometric measures (weight, body mass index (BMI), waist circumference (WC)), were done. MS was measured by a digital handgrip dynamometer in both right (MSR) and left (MSL) hand. Mean of MSR and MSL was considered as MS. RESULTS: A significant decrease was found for MS (p < 0.01) and MSR (p < 0.01) across tertiles of DII. Participants who had greater scores of DII also had lower MER (p < 0.01), even after adjustment for confounding factors (age, sex, education status, income, smoking, physical activity, body mass index and energy intake) (p < 0.02). Adherence to DII was significantly related to MSL (p < 0.01), ME (p < 0.01), and ME of the MEL (p = 0.02) in the crude model, which was disappeared after controlling for covariates. Those in the third compared to the lowest tertile of DII, had no significant difference in mean of FFM (p < 0.001), SMM (p < 0.001), and WC (p < 0.001). CONCLUSIONS: Higher DII scores were associated with less muscle strength and endurance among Iranian adults. Further studies are needed to confirm the veracity of our results. LEVEL OF EVIDENCE: Descriptive cross-sectional study, Level V.

The association between the Healthy Eating Index (HEI-2015) score and body composition among Iranian soccer players and referees: a cross-sectional study.

For an optimal performance, soccer players and referees need to consume a high-quality diet. The Healthy Eating Index (HEI) is a tool that can estimate diet quality and has been shown to be associated with body composition. The aims of the present study were first to determine the HEI-2015 score of the diets consumed by athletes and second its association with different body composition parameters of athletes. We conducted a cross-sectional study on 198 soccer players and referees. Dietary intakes were recorded using a validated food frequency questionnaire (FFQ), and HEI scores were calculated. Body composition parameters were measured using the bioelectrical impedance analysis. The mean score for the HEI-2015 was 65⋅04. A multiple linear regression model showed significant associations of the HEI-2015 score with percent body fat (PBF), percent muscle mass (PMM), waist-to-hip ratio (WHR) and waist-to-height ratio (WHtR) in male soccer players aged <18 years, body mass index (BMI) in male soccer players aged ≥18 years and BMI and waist-to-height ratio (WHtR) in male soccer referees after adjustment for covariates (P < 0⋅05). The mean overall score for the HEI-2015 shows that Iranian soccer players and referees have an acceptable quality of diet. We also found significant associations between the HEI-2015 score and different body composition parameters in male soccer players and referees but we did not find any significant association in female athletes (P > 0⋅05).

Effects of melatonin supplementation on oxidative stress: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: Previous studies showed that melatonin supplementation may suppress oxidative stress, however, the results have not been consistent. So, we conducted this meta-analysis to assess the precise relationship between melatonin supplementation and oxidative stress. METHODS: PubMed and Scopus were searched for randomized controlled trials that investigated the effect of melatonin supplementation on oxidative stress up to March 2020. Heterogeneity was assessed by Cochran's Q test and I-square (I 2) statistic. Data were pooled using the random effect model and standardized mean difference (SMD) was considered as the summary effect size. Also, standard methods were used for assessment of sensitivity analysis and publication bias. RESULTS: We included 15 related articles and our findings indicated that melatonin supplementation significantly increased total antioxidant capacity (TAC) level (SMD: 1.03, 95% CI: 0.24, 1.81, p=0.011) and reduced protein carbonyl (PCO) (SMD: -1.78, 95% CI: -2.97, -0.58, p=0.004) and malondialdehyde (MDA) levels (SMD: -0.94, 95% CI: -1.48, -0.40, p=0.001). Additionally, there was considerable effect on TAC level by using ≥20 mg/d melatonin and in people under 35 years old. MDA level also decreased using dosage of below 20 mg/d and in people ≥35 years old. CONCLUSIONS: The present study showed a promising effect of melatonin administration for reducing MDA, PCO, and increasing TAC levels. However, further studies especially with more attention to PCO level assessment are needed to confirm the findings of the present study in larger samples on different populations.