Soy Supplementation Does Not Affect Serum Adiponectin Levels in Adults: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Numerous studies have indicated that low levels of serum adiponectin are linked with the development of various chronic diseases. While some recent research has suggested that soy has a positive impact on serum adiponectin levels, the results are inconsistent. Therefore, we aim to conduct a thorough systematic review and meta-analysis of randomized controlled trials (RCTs) that investigate the effects of soy on serum adiponectin levels in adults. The search was conducted until March 2024 on PubMed, Scopus, Web of Science, and Cochrane Library databases to identify RCTs that studied the effects of soy supplementation on serum adiponectin levels. A random-effects model was used to pool the weighted mean differences (WMDs). Ten and nine RCTs were selected for the systematic review and meta-analysis, respectively. After analyzing data from 9 eligible RCTs, it was found that soy supplementation did not significantly impact the concentrations of adiponectin (WMD = -0.24 µg/mL; 95% confidence interval, -1.56 to 1.09; p = 0.72). However, there was significant heterogeneity between the studies (I2 = 89.8%, p < 0.001). Sensitivity analysis showed that overall estimates were not affected by the elimination of any study. We did not observe any evidence regarding publication bias. In conclusion, soy supplementation did not have a significant effect on adiponectin levels in adults. However, further RCTs are needed with longer intervention duration, higher doses, and studies conducted in different countries.

Effect of a plant-based diet on oxidative stress biomarkers in male footballers.

Proper nutrition plays a vital role in modulating oxidative status. There is an increasing popularity of plant-based dietary patterns among athletes. Therefore, the present study aimed to determine the plant-based diet index (PDI) score among male footballers and their non-athlete controls, as well as its relationship with oxidative biomarkers by evaluating the urinary excretion of F2alpha-isoprostane (F2a-IP) and 8-hydroxy-2'-deoxyguanosine (8-OHdG). A group of footballers (n = 45) and a healthy non-athlete group (n = 45) were selected. The two groups were matched based on body mass index (BMI) and age. The mean (standard deviation (SD)) age of the subjects was 22.88 (2.41) years, and their BMI was 22.08 (1.35) kg/m2. Anthropometric indices were evaluated, and fasting morning urine samples were analyzed to measure oxidative biomarkers. The PDI, unhealthy plant-based diet index (uPDI), and healthy plant-based diet index (hPDI) were calculated using valid food frequency questionnaire data. Generalized estimating equation models were used for all analyses. Compared to the non-athlete group, the PDI score was significantly greater in the footballer group (ß = 9.8; P < 0.001), while the differences between the two groups in uPDI and hPDI scores were not significant. Overall, footballers consumed more plant-based foods. By examining the relationship between dietary indices and oxidative biomarkers, only a negative association was observed between PDI score and F2a-IP level (ß = -1.25; P = 0.03). Based on the results, footballers were more adherent to a plant-based diet than non-athletes. In addition, it seems that following plant-based diets (the higher PDI) may exert beneficial effects on lowering F2a-IP levels due to improving the body's antioxidant status.

The Effect of a Combined Exercise Program on the Fatigue Severity of Patients with Breast Cancer Undergoing Chemotherapy: A Randomized Clinical Trial Study.

Background: Breast Cancer (BC) is one of the most common cancers in the world, including in Iran. Chemotherapy as one of the basic treatments for BC leads to many side effects such as fatigue. This study aimed to examine the effect of a combined exercise program on the intensity of fatigue in patients with BC undergoing chemotherapy. Materials and Methods: This clinical trial study was conducted on 64 patients with BC undergoing chemotherapy referring to the Seyyed al-Shoada and the Al-Zahra clinics from January to April 2022. Eligible patients who met inclusion criteria were recruited by the convenience sampling and then assigned randomly to intervention and control groups. The combined exercise program in the intervention group was done for 8 weeks as three sessions a week (34 sessions) each for 35-40 min. Piper's Fatigue Scale was completed for both groups before and after the intervention. Data were analyzed using descriptive and inferential statistical methods. Results: The results showed that the mean score of fatigue intensity in both control and intervention groups had a statistically significant difference after the intervention (p = 0.004). The mean fatigue intensity score in the intervention group decreased significantly from mean (SD) 8.17 (1.88) to 5.56 (1.74). Conclusions: Based on the results, a combined exercise program can reduce fatigue in patients with BC. Therefore, nurses can utilize exercise programs and practices as a subset of complementary medicine alongside other treatment methods, which can effectively promote cancer patients' quality of life by reducing their fatigue.

Effect of sesame (Sesamum indicum L.) consumption on glycemic control in patients with type 2 diabetes: A systematic review and meta-analysis of randomized controlled trials.

Conflicting evidence exists on the effect of sesame consumption on glucose metabolism in patients with type 2 diabetes (T2D). Therefore, this meta-analysis focuses on the relationship between sesame (Sesamum indicum L.) intervention and glycemic control in patients with T2D. Published literature was retrieved and screened from PubMed, Scopus, ISI Web of Science, and the Cochrane Library up to December 2022. Outcome measures included fasting blood sugar (FBS) concentrations, fasting insulin levels, and hemoglobin A1c (HbA1c) percentage. Pooled effect sizes were reported as weighted mean differences (WMDs) and 95% confidence intervals (CIs). Eight clinical trials (395 participants) were eligible for meta-analyses. Overall, sesame consumption significantly reduced serum FBS (WMD: -28.61 mg/dL, 95% CI: -36.07 to -21.16, p˂0.001; I2 = 98.3%) and HbA1c percentage (WMD: -0.99%, 95% CI: -1.22 to -0.76, p ≤ 0.001; I2 = 65.1%) in patients with T2D. However, sesame consumption did not significantly influence fasting insulin levels (Hedges's: 2.29, 95% CI: -0.06 to 4.63, p = 0.06; I2 = 98.1%). In summary, the current meta-analysis showed a promising effect of sesame consumption on glycemic control through reducing FBS and HbA1c, yet additional prospective studies are recommended, using higher doses and longer intervention period, to confirm the impact of sesame consumption on insulin levels in T2D patients.

The effect of cumin (Cuminum cyminum L.) supplementation on glycemic indices: A systematic review and meta-analysis of randomized controlled trials.

We aimed to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) to examine the effect of cumin supplementation on markers of glycemic control in adults. A comprehensive literature search was conducted up from inception to November 2020 on PubMed, Scopus, Web of Sciences, and Cochrane electronic databases. Studies that compared the effect of cumin with placebo on fasting blood sugar (FBS), serum insulin, and homeostasis model assessment-estimated insulin resistance (HOMA-IR) index in adults were considered eligible. Weighted mean difference (WMD) (with 95% confidence intervals) for endpoints were calculated using the random-effects model. Finally, a total of eight RCT studies involving 552 participants were included in the review. The results of the meta-analysis suggest that cumin supplementation did not significantly alter serum FBS (WMD: -17.77 mg/dl; 95% CI: -36.42 to 0.87, p = .06), insulin (WMD: -0.49 Hedges' g; 95% CI: -1.19 to 0.21, p =.16) levels and HOMA-IR (WMD: -0.06; 95% CI: -0.21 to 0.10, p = 0.48) index. These results do not support the use of cumin supplementation for improving glycemic markers in adults. However, further high-quality trials are still needed to confirm these results.

The effects of quinoa seed supplementation on cardiovascular risk factors: A systematic review and meta-analysis of controlled clinical trials.

This meta-analysis was designed to determine the effect of quinoa seed on cardiovascular disease (CVD) risk factors in adults. PubMed, Scopus, ISI Web of Science, and Cochrane library were searched electronically from their inception to February 2020 to identify eligible RCTs. We calculated the pooled estimates of weighted mean differences (WMDs) and their 95% confidence intervals (CIs) by using random-effects models. Five eligible RCTs representing 206 subjects were enrolled. The pooled result showed that quinoa seed supplementation significantly lowered the body weight (WMD: -1.26 kg, 95% CI: -2.35, -0.18, p = .02), waist circumference (WC) (WMD: -1.15 cm, 95% CI: -2.08, -0.21, p = .01), fat mass (FM) (WMD: -0.59%, 95% CI: -1.14, -0.03, p = .03), insulin serum level (WMD: -0.86 pmol/L, 95% CI: -13.38, -1.59, p = .01), triglyceride (TG) (WMD: -7.20 mg/dl, 95% CI: -9.52, -4.87, p < .001), total cholesterol (TC) (WMD: -6.86 mg/dl, 95% CI: -10.64, -3.08, p < .001), and low density lipoprotein (LDL) (WMD: -3.08 mg/dl, 95% CI: -5.13, -1.03, p = .003) levels. However, no significant changes were seen in other markers (p > .05). The current evidence suggests that quinoa seed might be utilized as a possible new effective and safe supplementary option to better prevent and control CVD in humans.

The Effect of Arginine Intake on Colorectal Cancer: a Systematic Review of Literatures.

Colorectal cancer (CRC) is one of the major reasons of mortality in the worldwide. There is clear evidence that some amino acids such as arginine can improve CRC and its complications. Hence, in this systematic review we evaluated the association between arginine intake and CRC improvement. We searched the PubMed, Scopus, ISI Web of Science, Cochrane library, and Google Scholar databases by using proper keywords to find the relevant literatures, published to March 2019. Nine human studies of 523 screened articles were included in present systematic review. The majority of studies have found a positive association between consumption of arginine and CRC improvement. Increased inducible nitric oxide (NO) synthase expression and subsequently increasing the NO concentration in the tumor and/or serum, after arginine intake may be responsible for these protective effects. Also, arginine consumption may reduce cell proliferation in CRC and it can enhance immune function after remove the tumor. Although the benefits of arginine consumption in CRC patients were reported in previous trials, the finding need replication in well-designed studies before final conclusion.

The efficacy of propolis on markers of glycemic control in adults with type 2 diabetes mellitus: A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVES: The impetus for the current study was to evaluate the efficacy of propolis supplementation on markers of glycemic status in adults with type 2 diabetes mellitus (T2DM). METHODS: A comprehensive search was conducted in PubMed, Scopus, Cochrane Library, Web of Science, and Google Scholar up to August 2018, identifying randomized controlled trials investigating the effect of propolis supplementation on glycemic markers in adults with T2DM. Cochrane Collaboration tool was used to evaluate the risk of bias assessment. A random-effects model was applied in the meta-analysis to compensate for potential heterogeneity among the included studies. RESULTS: Six randomized controlled trials comprising 373 participants were included in the systematic review and meta-analysis. The results of the meta-analysis revealed significant reductions in fasting plasma glucose (-13.51 mg/dl; 95% CI [-24.98, -2.04]) and hemoglobin A1C (-0.52%; 95% CI [-0.94, -0.10]) concentrations following propolis supplementation. However, no significant lowering effect was observed in fasting insulin levels (-0.53 pmol/L; 95% CI [-1.69, 0.63]) or homeostasis model assessment of insulin resistance (-0.543; 95% CI [-1.72, 0.64]). CONCLUSION: This systematic review and meta-analysis suggested that propolis supplementation may be effective in controlling glycemic levels for T2DM patients. Further studies are needed to confirm these results.

A comparative study of the effect of green tea and sour tea on blood pressure and lipid profile in healthy adult men.

BACKGROUND: Cardiovascular diseases (CVD) are a set of metabolic disorders affecting heart and blood vessels. Green tea and sour tea (Hibiscus sabdariffa L.) have attracted significant attention recently due to their high popularity, nutrient profile and therapeutic effects. The aim of the present study was to compare the effects of green tea and sour tea supplementation on blood pressure and lipid profile in healthy adult men. METHODS: This randomized, double-blind, placebo-controlled trial included 54 healthy adult men. The participants were randomly assigned to two intervention groups receiving 450 mg green tea or sour tea and one placebo group which consumed 450 mg placebo (maltodextrin) for 6 weeks. Blood pressure, lipid profile, dietary intake and physical activity were measured pre- and post-intervention and compared. RESULTS: After 6 weeks of intervention, sour tea supplementation led to a significant decrease in systolic blood pressure (SBP) compared with the placebo group. However, we faild to find any significant difference in SBP between green tea and control groups. Also, no significant changes were observed in diastolic blood pressure (DBP) and lipid profile between the three groups. In comparison with baseline, there was a significant increase in the mean level of serum high-density lipoprotein cholesterol (HDL-C) in green tea and sour tea groups. Also, the interventions resulted in significant decrease in the mean levels of serum total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-C) and DBP in the sour tea group compared with the pre-intervention value. CONCLUSION: On the basis of our findings, sour tea supplementation led to decreased SBP in healthy men compared with the placebo, but there was no significant difference between their effects on DBP and lipid profile.

The Effect of Green Tea and Sour Tea (Hibiscus sabdariffa L.) Supplementation on Oxidative Stress and Muscle Damage in Athletes.

OBJECTIVE: Additional oxygen consumption during intense exercises may lead to oxidative stress and contribute to muscular fatigue. Green tea and sour tea (Hibiscus sabdariffa L.), which contain various flavonoids and polyphenols, have many healthful properties such as anticarcinogenic, anti-inflammatory, and heart protecting effects. The aim of the present study was to assess the effects of green tea and sour tea supplementation on oxidative stress and muscle damage in soccer athletes. METHODS: This randomized, double-blind control trial was conducted on 54 male soccer players. Participants were randomly assigned to three groups to receive: 450 mg/d green tea extract (GTE) in the first group (n = 18), 450 mg/d sour tea extract (STE) in the second group (n = 18) and 450 mg/d maltodextrin in the control group (n = 18). Fasting whole blood samples were taken under resting conditions at the beginning and the end of the study to quantify the serum levels of muscle damage indices, aspartate aminotransferase (AST), creatine kinase (CK), lactate dehydrogenase (LDH), and oxidative stress biomarkers, malondialdehyde (MDA), and total antioxidant capacity (TAC). RESULTS: After six weeks intervention, athletes who received GTE and STE supplements compared with the placebo had a significantly decreased MDA level (P = 0.008). Furthermore, STE supplementation resulted in a significant increase in TAC level compared with GTE and placebo groups (P = 0.01). However, supplementation with GTE and STE had no significant effects on muscle damage indices. CONCLUSION: GTE and STE supplementation have beneficial effects on oxidative stress status in male athletes. However, both kinds of tea extract did not affect muscle damage status.

The effects of two methods of reflexology and stretching exercises on the severity of restless leg syndrome among hemodialysis patients.

BACKGROUND: Restless leg syndrome prevalence is high among the patients undergoing hemodialysis. Due to several side effects of medicational treatments, the patients prefer non-medicational methods. Therefore, the present study aimed to investigate the effects of two methods of reflexology and stretching exercises on the severity of restless leg syndrome among patients undergoing hemodialysis. MATERIALS AND METHODS: This study is a randomized clinical trial that was done on 90 qualified patients undergoing hemodialysis in selected hospitals of Isfahan, who were diagnosed with restless leg syndrome through standard restless leg syndrome questionnaire. They were randomly assigned by random number table to three groups: Reflexology, stretching exercises, and control groups through random allocation. Foot reflexology and stretching exercises were conducted three times a week for 30-40 min within straight 4 weeks. Data analysis was performed by SPSS version 18 using descriptive and inferential statistical analyses [one-way analysis of variance (ANOVA), paired t-test, and least significant difference (LSD) post hoc test]. RESULTS: There was a significant difference in the mean scores of restless leg syndrome severity between reflexology and stretching exercises groups, compared to control (P < 0.001), but there was no significant difference between the two study groups (P < 0.001). Changes in the mean score of restless leg syndrome severity were significantly higher in reflexology and stretching exercises groups compared to the control group (P < 0.001), but it showed no significant difference between reflexology massage and stretching exercises groups. CONCLUSIONS: Our obtained results showed that reflexology and stretching exercises can reduce the severity of restless leg syndrome. These two methods of treatment are recommended to the patients.

Effect of Resistance Training on Capillary Density Around Slow and Fast Twitch Muscle Fibers in Diabetic and Normal Rats.

BACKGROUND: It is well accepted that skeletal muscle conforms to exercise stimulus by increasing capillary density and angiogenesis, but there is less evidence regarding the effect of resistance training on capillary density in flexor hallucis longus (FHL) and soleus muscle. OBJECTIVES: In this study, we evaluated the effect of resistance training on capillary density around soleus and FHL muscles in type 1 diabetic rats. MATERIALS AND METHODS: Thirty-six male rats were divided into four groups: (1) control; (2) diabetic; (3) diabetic trained and (4) control trained (n = 9 each). A Single intraperitoneal injection of Streptozotocin at a dose of 55 mg/kg was used for induction of diabetes. The rats in the trained group undertook one training session per day for 3 days/week. Training was done with the use of a 1 meter high ladder inclined at 80°. After 4 weeks, the plasma nitrite concentrations were measured. Capillary/fiber ratio was determined around soleus and FHL muscles by immunohistochemistry. RESULTS: Plasma Nitric Oxide (NO) concentration was increased after resistance training in diabetic animals (P < 0.05). Capillary/fiber ratio around the soleus muscle of diabetic group was more than control rats. Resistance training did not alter capillary/fiber ratio in diabetic animals (1.00 ± 0.6 vs. 1.07 ± 0.07, respectively). Capillary/fiber ratio around FHL muscle was significantly different between diabetic and control and did not alter after exercise (diabetes: 1.1702 ± 0.09; diabetic trained: 1.1714 ± 0.08; control: 0.79 ± 0.08; control trained: 0.73 ± 0.03). There was a positive correlation between plasma NO concentration and capillary density in the soleus muscle (R2 = 0.65). CONCLUSIONS: Resistance training could not improve capillary/fiber ratio in soleus and FHL muscle of diabetic animals in spite of increase in some angiogenic factors including NO.

The relationship between social capital and the way of spending leisure time, based on physical activities.

BACKGROUND: Today, social capital is a need in the society. Also, leisure time and physical activities are among the most important productive sources of social capital, which have been realized recently. This study aims to find the relationship between social capital and physical leisure time of the faculty members of Isfahan University of Medical Sciences. MATERIALS AND METHODS: A descriptive correlation method was used in this study. Two questionnaires were used for data collection. Social capital questionnaire is based on SCAT Model. Also, leisure time questionnaire was made by the researcher for which face and content validity was verified by experts. Reliability coefficients by using Cronbach's alpha coefficients were calculated as 0.92 and 0.82, respectively. Sample population was calculated by Cochran's formula, and 150 people were selected as the sample using multiple cluster sampling by taking the sex and college into consideration as the variables. FINDINGS: According to the findings, there was a direct relationship between a combination of social capital parameters (including commitment, attitude, trust, participation, mutual relationship, social norm, and unity) and the way of spending physical leisure time (R = 0.659, P = 0.000). Among the parameters, "commitment" was significant with a beta coefficient B = 0.293 and P = 0.044 and social norms was significant with a beta coefficient B = 0.196 and P = 0.047, but the rest of the factors were not significant. CONCLUSION: Playing sport and doing physical activities in the leisure time and also taking part in group activities and their membership provide a situation for people to respect the group interests through communication. Such activities can cause the level of social capital and its factors to be increased.

Pathology of Isfahan University of Medical Sciences based on Weisbord six box model and its relation with mental health.

BACKGROUND: The aim of this research was to study the pathology of Isfahan University of Medical Sciences based on Weisbord six box model and to find its relation with mental health. MATERIALS AND METHODS: The research method followed was a descriptive survey. The statistical society consisted of all staffs of the Isfahan University of Medical Sciences consisting of professors in the year 2012 (personnel of deputy of treatment, deputy of training, cultural-student deputy, supporting deputy, deputy of food and drugs, health deputy, and deputy of research). The number of subjects in the mentioned society was 1647, sample size was 332 Based on Cochrane's formula. They were selected by random sampling method in proportion with the statistical society. The measurement instruments included organizational pathology questionnaire (ODQ) with 35 questions and the questionnaire of mental health standard [General Health Questionnaire (GHQ)] with 28 questions. The validity of the questionnaires obtained from reviews by faculties and experts, and the reliability of the questionnaire assessed through Cronbach's coefficient were 0.86, 0.85, and 0.76, respectively. To analyze data, the statistical methods such as single-variance t-test, regression analysis, correlation coefficient, Kolmogorov-Smirnov test, and Multivariate Analysis of Variance (MANOVA) were used. FINDINGS: The findings of research demonstrated that the organizational damage based on six box model was seen only in the reward component at the Isfahan University of Medical Sciences. Mental health of persons in the sample group of Isfahan University of Medical Sciences was in the suitable status. There was a meaningful and positive interrelation between mental health and attitude toward the organizational damages in the dimensions of communications, useful merchandises, and attitude to change. However, no meaningful interrelation was seen between aims, structure, leadership, and reward and mental health. There was no meaningful difference between the averages of staffs' attitude about their mental health per the demographic properties. CONCLUSIONS: The results show that there was a meaningful and positive interrelation between mental health and attitude toward the organizational damages in the dimensions of communications, useful merchandises, and attitude to change. Therefore, managers should focus on all parts of the organization and the pathology strengths and weaknesses in these areas.

Investigation of the SWB and its relation with demographic parameters in patients with breast cancer referred to an oncology hospital affiliated to the Isfahan university of medical sciences.

BACKGROUND: Spiritual well-being is well-recognized as a factor that affects cancer patients' quality of life, quality of care, and satisfaction. There is evidence that supports the fact that patients' spiritual needs are associated with better quality of care, higher hospice utilization, and less aggressive care at the end of life. However, few studies have examined the Spiritual well-being (SWB) in cancer patients. Less is known about spirituality; furthermore, no published research about SWB and its relationship with demographic parameters in breast cancer patients exists; this made us carry out this project. MATERIALS AND METHODS: This cross-sectional study was a descriptive - analytical one, conducted on 297 breast cancer patients, with a simple sampling methodology. The data collection instrument included a questionnaire containing two parts (demographic information and standard SWB Scale questionnaire). The data were analyzed with 95% confidence by SPSS18, using descriptive and analytic statistics. RESULTS: According to the results of the present study, SWB of most of the study subjects (52.52%) was at a moderate level. Results showed that the average score for religious aspect of spiritual well-being (RWB) was 51.38 ± 8.17 for 60, average score for the existential aspect of spiritual well-being (EWB) was 42.47 ± 10.21 for 60, and the total score of SWB was 93.69 ± 10.04 for 120. Based on the study findings, there was a statistically significant correlation between the SWB and age (P = 0.03, r = 0.59), educational level (P = 0.04, r = -0.58), and marital status (P = 0.001), of breast cancer patients. CONCLUSION: According to the results of the present study, the SWB of most study subjects was at a moderate level. Furthermore, according to the results there was a correlation between some important demographic parameters in women with breast cancer and SWB. Hence, it is necessary for the treatment team to assess and improve the SWB of patients; meanwhile the role of nurses is highlighted. In fact, the nurse is the first person who can recognize the spiritual needs of a patient and even his/her family, and can be effective in meeting the spiritual needs and improving their SWB. Therefore, it is strongly recommended that in patients with cancer, a holistic care plan, based on spiritual care, development, and education of patients be applied, as it is considered to improve their SWB.

Effect of resistance training on plasma nitric oxide and asymmetric dimethylarginine concentrations in type I diabetic rats.

BACKGROUND: Asymmetric dimethylarginine (ADMA) has a predominant role in progression of some cardiovascular diseases, including diabetes. It interferes with L-arginine in production of nitric oxide (NO) by inhibition of NO synthase. The purpose of this study was to evaluate the effect of resistance training on plasma NO and ADMA concentrations in type 1 diabetic male rats. METHODS: Thirty-six male wistar rats were randomly divided into four groups: (1) control; (2) diabetic; (3) diabetic trained, and (4) control trained (n = 9 each). In the trained groups, the animals undertook one training session per day, 3 days/week, for 4 weeks. At the end of experiment, blood samples were taken and the concentrations of plasma glucose, insulin, lipid profile, NO and ADMA concentrations were determined. RESULTS: plasma ADMA concentration showed a significant increase in diabetic rats compare to control group (0.73 ± 0.07 vs. 0.62 ± 0.04 µmol/l; P < 0.05). The plasma ADMA level in the trained diabetic and control were lower than the sedentary groups, although it was not statistically significant. Plasma NO concentration in diabetic group was lower than control (P < 0.05). Resistance training significantly increased plasma NO concentration in diabetic animals (P < 0.05). CONCLUSION: Elevated ADMA level in diabetic animals can normalize during resistance exercise. Reduced ADMA level and increased NO level following resistance training might improve cardiovascular risk in diabetic subjects.

The effects of quercetin supplementation on body composition, exercise performance and muscle damage indices in athletes.

BACKGROUND: Flavonoids comprise a large group of plant metabolites, 6,000 of which have been identified to date. Some studies have shown the increased aerobic performance and maximal oxygen consumption (VO(2max)) and therefore fitness following quercetin intake as a result of elevated number of intracellular mitochondria caused by the flavonoid. METHODS: This double-blind clinical trial comprised 60 male students having an athletic history of at least 3 years. Body composition, exercise performance, and some blood biomarkers were analyzed. The individuals were selected by convenient sampling, and then were assigned into four groups of equal number by using permuted block randomization. The first to fourth groups received a 500 mg supplemental quercetin capsule plus a 250 mg vitamin C pill, a 500 mg supplemental quercetin capsule plus a 250 mg placebo vitamin C pill, a 500 mg placebo quercetin capsule plus a 250 mg vitamin C pill, and a 500 mg placebo quercetin capsule plus a 250 mg placebo vitamin C pill, respectively, daily for 8 weeks. The participants were asked to continue their routine diet and physical activity during the study and they were monitored through phone calls or text messages. RESULTS: Lean body mass, total body water, basal metabolic rate, and total energy expenditure increased significantly in the quercetin group after intervention. On the other hand, VO(2max) increased in the "quercetin" and "quercetin + vitamin C" groups following the intervention, non-significantly. CONCLUSION: Our findings suggest that supplementation with quercetin in athletes may improve some indices of performance.

Does quercetin and vitamin C improve exercise performance, muscle damage, and body composition in male athletes?

BACKGROUND: Quercetin is a bioflavonoid occurs in many food items. Some previous studies on quercetin showed the inconsistent results on exercise performance and muscle damage in athletes. The aim of this study was to determine the effects of 8 weeks of quercetin supplementation on exercise performance and muscle damage indices in student athletes. METHODS: This placebo-controlled, double-blind clinical trial was conducted on 60 male students for 8 weeks. The subjects were randomly assigned to one of the four groups: a) quercetin (500 mg/day quercetin + 200 mg/day placebo), b) quercetin+ vitamin C (500 mg/day quercetin + 200 mg/day vitamin C), vitamin C (500 mg/day placebo + 200 mg/day vitamin C), and placebo (500 mg/day placebo + 200 mg/day placebo). Time to exhaustion (TTE) for measuring performance, aspartate transaminase (AST), and creatine kinase (CK) for measuring muscle damage and body fat percent (BFP) were measured before and after intervention. RESULTS: CK levels reduced in group 1 significantly (P=0.045) and BFP reduced in group 1, 3, and 4, significantly, too (P=0.018, P=0.013, and P=0.043, respectively). Whereas statistically significant changes between groups were not observed for TTE, AST, CK, and BFP after 8 weeks of intervention. CONCLUSIONS: Supplementation with quercetin and vitamin C for 8 weeks did not improve exercise performance but reduced muscle damage and body fat percent in healthy subjects.

The effect of quercetin supplementation on selected markers of inflammation and oxidative stress.

BACKGROUND: Athletes use flavonoids as antioxidant to enhance endurance and physical performance. In vitro data indicate flavonoids have antioxidative and antiinflammatory functions but data in human studies are limited. The aim of this study was to determine the effects of a 2-month flavonoid quercetin supplementation on oxidative stress and inflammatory biomarkers in nonprofessional athletes with regular exercise. MATERIALS AND METHODS: The randomized double-blind clinical trial was done among subjects with systematic and regular exercise for 8 weeks in four groups, each containing 15 individuals: 500 mg quercetin + 250 mg vitamin C as pro-oxidant (Q+C), 500 mg of quercetin alone (Q), 250 mg of vitamin C alone (C), and placebo (Control). IL-6, CRP, E-selectin and F2-isoprostane were measured before and after intervention. RESULTS: In 60 participants with mean (±SD) age of 21.0 ± 1.6 years, statistically significant within group differences were observed in IL-6 (P<0.1), CRP (P<0.01) and F2-isoprostane for group 1 and pre- and postchanges in E-selectin was marginally significant for all study groups (P<0.1). Group 1 had marginally smaller F2-isoprostane (P<0.1) and interleukin 6 than control group (P<0.05) and there were marginally differences in CRP between respondents in group 1 and 2 with the control group (P<0.1). CONCLUSIONS: Eight-week supplementation with quercein-vitamin C was effective in reducing oxidative stress and reducing inflammatory biomarkers including CRP and IL-6 with little effect on E-selectin in healthy subjects.

Supplement consumption in body builder athletes.

BACKGROUND: Widespread use of supplements is observed among world athletes in different fields. The aim of this study was to estimate the prevalence and determinants of using supplements among body builder athletes. METHODS: This cross-sectional study was conducted on 250 men and 250 women from 30 different bodybuilding clubs. Participants were asked to complete a self-administered standardized anonymous check-list. RESULTS: Forty nine percent of the respondents declared supplement use. Men were more likely to take supplements than women (86.8% vs. 11.2%, p = 0.001). Reasons for using supplements were reported to be for health (45%), enhancing the immune system (40%) and improving athletic performance (25%). Most athletes (72%) had access to a nutritionist but underused this resource. Coaches (65%) had the greatest influence on supplementation practices followed by nutritionists (30%) and doctors (25%) after them. CONCLUSIONS: The prevalence of supplement use among bodybuilders was high. Sex, health-related issues and sport experts were determinant factors of supplement use.