The prevalence of obesity and underweight in celiac patients at the time of diagnosis: a systematic review and meta-analysis.

BACKGROUND: This study aimed to estimate the prevalence of obesity, overweight, and underweight in celiac disease (CD) at diagnosis before starting the Gluten-free diet (GFD). METHODS: A comprehensive search was conducted in PubMed, Embase, Scopus, and Web of Science until July 2024 to find the cross-sectional and longitudinal studies that measured the body mass index (BMI) in CD patients at diagnosis. The risk of bias assessment was conducted using the Newcastle-Ottawa Quality Assessment scale. Meta-regression analyses were applied to understand whether weight status is associated with CD. RESULTS: A total of 23 studies involving 15,299 CD patients and 815,167 healthy individuals were included in this study. In newly diagnosed CD patients, pooled estimates of the prevalence of obesity, overweight, and underweight before GFD were 11.78%, 18.42%, and 11.04%, respectively. The prevalence of overweight and obesity in newly diagnosed CD patients increased from 22.15% in 2003-2009 to 32.51% in 2016-2021. Meta-regression analyses indicated that the CD patients with higher BMI had a higher mean age (p = 0.001), and female gender had a marginally significant (p = 0.055) association with higher BMI. Only a few CD patients were underweight at the time of diagnosis, and more patients were overweight/obese. CONCLUSIONS: our meta-analysis demonstrated that only a few CD patients were underweight at the time of diagnosis, and almost 37% were overweight or obese. Meta-regression showed a significant association between higher BMI and higher mean age and female gender. A delay or failure for diagnosis of CD is more common in overweight/obese patients, resulting in more progression of the disease and counteracting any advantages of diagnosis.

Dietary advanced glycation end-products (dAGEs) are not associated with the risk of cancer incidence. A systematic review and meta-analysis of prospective cohort studies.

A growing body of evidence indicates the association of dietary advanced glycation end-products (dAGEs) with the risk of cancer. This systematic review and meta-analysis aimed to assess the overall association between dAGEs and cancer incidence. An extensive search was carried out through online databases including PubMed, Scopus, and Web of Science up to June 2024. All reported HRs and their 95% CIs for risk of cancer were used to estimate log HRs and their standard errors (SEs). The overall risk estimate was obtained using a random effects model. Inter-study heterogeneity was determined using Cochrane's Q test and I-squared. Five prospective cohort studies with a total of 1,220,096 participants and 23,229 incident cancer cases (2193 pancreatic cancers, 11,443 breast cancers, 6162 colorectal cancers, and 3431 total cancers) were included in this meta-analysis. Compared with the lowest category of dAGEs, the pooled hazard ratio (HR) for overall cancers was 1.04 (95% CI: 0.94, 1.15; I 2 = 67.9%) for the highest category of dAGEs. Pooled estimates for different types of cancer showed no significant relationship between dAGEs and risk of breast cancer (HR: 1.119; 95% CI: 0.868, 1.444; I 2 = 77.6%; N = 2 studies), pancreatic cancer (HR: 1.242; 95% CI: 0.971, 1.588; I 2 = 0.0%; N = 2 studies), colon cancer (HR: 10.985; 95% CI: 0.887, 1.094; I 2 = 0.0%; N = 2 studies) and rectal cancer (HR: 0.940; 95% CI: 0.616, 1.433; I 2 = 57.7%; N = 2 studies). Dietary AGEs had no significant link with cancer risk. More well-designed prospective studies are required.

Correction: Theobromine supplementation in combination with a low-calorie diet improves cardiovascular risk factors in overweight and obese subjects with metabolic syndrome: a randomized controlled trial.

Correction for 'Theobromine supplementation in combination with a low-calorie diet improves cardiovascular risk factors in overweight and obese subjects with metabolic syndrome: a randomized controlled trial' by Elham Sharifi-Zahabi et al., Food Funct., 2023, 14, 8431-8441, https://doi.org/10.1039/D3FO00555K.

Associations of circulating advanced glycation end products and their soluble receptors with cancer risk: A systematic review and meta-analysis of observational studies.

Advanced glycation end products (AGE) in complex with their receptors (RAGE) cause a chronic inflammatory state in the body, which is the major mechanism in cancer development. This study aimed to conduct a systematic review and meta-analysis on the observational studies investigating the association between AGEs / sRAGE and cancer incidence. The PubMed, Scopus, and Web of Science databases were comprehensively searched to identify papers focused on the associations of sRAGE and AGEs with cancer incidence up to May 2023. Eight studies with a total of 7690 participants were included in the analysis to evaluate the association between circulating sRAGE and cancer incidence. The results indicated that circulating sRAGE (per 100 ng/L) had a significant inverse association with cancer incidence (RR 0.977; 95% CI 0.956, 0.999; p = 0.036; I 2 = 73.3%). The association between AGEs and cancer incidence was evaluated in 8 studies with a total of 3718 individuals. Serum concentrations of AGEs (per 100 µg/L) were not associated with the risk of cancer incidence (RR 0.988; 95% CI 0.974, 1.002; p = 0.08; I2 = 78.8%). Our findings revealed that a higher circulating sRAGE may have a protective effect against cancer incidence.

Theobromine supplementation in combination with a low-calorie diet improves cardiovascular risk factors in overweight and obese subjects with metabolic syndrome: a randomized controlled trial.

Background & aims: The beneficial effects of theobromine (TB) on obesity and features of metabolic syndrome (MetS) have been reported in several studies. However, the findings are equivocal. The present study aimed to investigate the effects of 12 week pure TB supplementation (450 mg day-1) combined with a low-calorie diet on the anthropometric and metabolic syndrome indices in overweight and obese adults with MetS. Methods: In a randomized double-blind parallel controlled trial, 80 participants aged 40-55 years were randomly assigned to take 450 mg day-1 TB or placebo along with a low-calorie diet for 12 weeks. Dietary intake, anthropometric indices, blood pressure, lipid profile and glycemic indices were assessed at the start and end of the intervention. Results: Seventy-two participants completed the study. After 12 weeks, TB supplementation significantly decreased the waist circumference (WC) (-0.86 cm; P = 0.045), LDL-c/HDL-c (-0.26; P = 0.008), TG/HDL-c (-0.41; P = 0.001), TC/HDL-c (-0.38; P = 0.006) and increased HDL-c (1.72 mg dl-1; P = 0.036) compared to the placebo group. There were no significant differences regarding body weight, BMI, hip circumference (HC), hip-to-waist circumference ratio (WHR), systolic and diastolic blood pressure, fasting levels of total cholesterol (TC), triacylglycerol (TAG), low-density lipoprotein cholesterol (LDL-c), fasting blood glucose, insulin, homoeostatic model assessment for insulin resistance (HOMA-IR) and homeostasis model assessment of ß-cell function (HOMA-ß) between the two groups (p > 0.05). Conclusion: The results of the current study revealed that TB supplementation along with a low-calorie diet had favorable effects on WC, LDL-c/HDL-c, TG/HDL-c, TC/HDL-c, and serum level of HDL-c in overweight and obese subjects with MetS. Trial registration number: IRCT20091114002709N59. Registration date: 5 March 2022.

A comprehensive insight into the molecular effect of theobromine on cardiovascular-related risk factors: A systematic review of in vitro and in vivo studies.

Theobromine may have beneficial effects on cardiovascular risk factors. This study aimed to find molecular effects of theobromine on lipid profile, glycemic status, inflammatory factors, and vascular function through a comprehensive assessment of all in vitro and in vivo studies. The search process was started at 18 July 2022. Databases including PubMed, Scopus, and Web of Science were searched to find all articles published up to 18 July 2022. Nineteen studies were included in this study. In vitro studies showed the improving effects of theobromine on inflammatory markers. Of four animal studies assessing the effect of theobromine on inflammatory markers, two reported favorable effects. Among five animal studies assessing the effects of theobromine on lipid profile, three reported improving effects on either triglyceride, total cholesterol, low- or high-density lipoprotein cholesterol. Of the three human studies, two revealed that theobromine had improving effects on lipid profile. A favorable effect of theobromine on augmentation index was also reported in two RCTs. The results for other outcomes were inconclusive. Theobromine may have favorable effects on inflammatory factors, lipid profile, and vascular function markers. However, studies with a longer duration and lower, dietary-relevant doses are required for future confirmation.

Role of alpha-lipoic acid in vascular function: A systematic review of human intervention studies.

Alpha-lipoic acid (ALA) has long been the focus of interest due to its promising effects on cardiometabolic risk factors. The aim of this systematic review was to summarize findings from existing human intervention studies evaluating the effect of ALA on vascular function. We performed a systematic search in the PubMed, SCOPUS, and Web of science electronic databases from inception until 1 July 2020. A total of 1106 records were identified from the database search, of which 12 were eligible: nine addressed chronic effects and three measured acute effects of ALA on vascular function. Of 11 trials that evaluated endothelial function by methods such as flow-mediated dilation (n = 7), reactive hyperemia (n = 2) and ACh-induced endothelium-dependent vasodilation (n = 2), 10 reported a significant improvement in endothelial function. In contrast, none of six trials examining the response of endothelium-independent vasodilation reported the favorable impact. The effect of ALA on arterial stiffness measures has been poorly studied. ALA appears to improve endothelial function through increasing the bioavailability of endothelium-derived nitric oxide as well as decreasing oxidative stress and inflammation. In conclusion, these results suggest improvement of endothelial function, but not endothelium-independent vasodilation as a potential mechanism by which ALA attenuates cardiovascular diseases.

High-intensity interval training with or without chlorella vulgaris supplementation in obese and overweight women: effects on mitochondrial biogenesis, performance and body composition.

The beneficial effects of high-intensity interval training (HIIT) and chlorella vulgaris (CV) on body composition and mitochondrial biogenesis have been shown in some mechanistic studies. This study aimed to determine the effects of CV and/or HIIT on mitochondrial biogenesis, performance and body composition among overweight/obese women. There was a significant reduction in the fat mass (FM) of the CV + HIIT group, as compared with the placebo group (P = 0·005). A marginal significant increase in body water (P = 0·050) and PPAR-γ coactivator-1α (P = 0·050) was also found only in the CV + HIIT group, as compared with the placebo. Relative (P < 0·001) and absolute (P < 0·001) VO2max, as well as Bruce MET (P < 0·001), were significantly increased in the HIIT and HIIT + CV groups. Besides, the synergistic effect of CV and HIIT on the Bruce MET increment was found (interaction P-value = 0·029). No significant changes were observed in BMI, fat-free mass, visceral fat, silent information regulator 1 and fibroblast growth factor-21. In this randomised clinical trial, forty-six overweight/obese women were assigned to four groups including CV + HIIT and HIIT + placebo groups that received three capsules of CV (300 mg capsules, three times a day) or corn starch, in combination with three sessions/week of HIIT. CV and placebo groups only received 900 mg of CV or corn starch, daily, for 8 weeks. Biochemical assessments, performance assessment and body composition were obtained at the beginning and end of the intervention. HIIT may be, therefore, effective in improving mitochondrial biogenesis, performance and body composition in overweight/obese women.

Role of whey protein in vascular function: a systematic review and meta-analysis of human intervention studies.

Whey protein (WP) has been heavily appreciated as a rich source of bioactive peptides, with potential benefits for cardiovascular health. This study constitutes a systematic review and meta-analysis summarising the effects of WP consumption on vascular reactivity, arterial stiffness and circulatory biomarkers of vascular function. We searched electronic databases, including PubMed, SCOPUS and Web of science for relevant articles from inception to July 2020. Original clinical trials published in English-language journals that investigated the effects of WP on vascular function were eligible. A total of 720 records were identified in the initial search; from these, sixteen were included in our systematic review and thirteen in meta-analysis. The pooled analysis of six studies showed a significant increase in flow-mediated dilation (FMD) after WP consumption (weighted mean differences (WMD): 1·09 %, 95 % CI: 0·17, 2·01, P= 0·01). Meta-analysis of available data did not show any significant reduction in arterial stiffness measures including augmentation index (effect sizes: 7, WMD: -0·29 %, 95 % CI: -1·58, 0·98, P= 0·64) and pulse wave velocity (effect sizes: 4, WMD: -0·72 m/s, 95 % CI: -1·47, 0·03, P= 0·06). Moreover, the pooled analysis of six effect sizes showed no significant effects on plasma levels of nitric oxide following WP supplementation (WMD: 0·42 µmol/l, 95 % CI: -0·52, 1·36, P= 0·38). The overall results provided evidence supporting a protective effect of WP on endothelial function measured by FMD, but not for arterial stiffness measures and circulatory biomarker of vascular function. Further research is required to substantiate the benefits of WP on vascular function.

Carotenoids supplementation and inflammation: a systematic review and meta-analysis of randomized clinical trials.

The aim of this study was to perform a systematic review and meta-analysis on randomized controlled trials investigating the effects of carotenoids on selected inflammatory parameters. PubMed, SCOPUS, and Web of science were searched from inception until April 2021. The random-effect model was used to analyze data and the overall effect size was computed as weighted mean difference (WMD) and corresponding 95% of confidence interval (CI). A total of 26 trials with 35 effect sizes were included in this meta-analysis. The results indicated significant effects of carotenoids on C-reactive protein (CRP) (WMD: ‒0.54 mg/L, 95% CI: ‒0.71, ‒0.37, P < 0.001), and interleukin-6 (IL-6) (WMD: ‒0.54 pg/mL, 95% CI: ‒1.01, ‒0.06, P = 0.025), however the effect on tumor necrosis factor-alpha (TNF-α) was not significant (WMD: ‒0.97 pg/ml, 95% CI: ‒1.98, 0.03, P = 0.0.059). For the individual carotenoids, astaxanthin, (WMD: ‒0.30 mg/L, 95% CI: ‒0.51, ‒0.09, P = 0.005), lutein/zeaxanthin (WMD: ‒0.30 mg/L, 95% CI: ‒0.45, ‒0.15, P < 0.001), and ß-cryptoxanthin (WMD: ‒0.35 mg/L, 95% CI: ‒0.54, ‒0.15, P < 0.001) significantly decreased CRP level. Also, only lycopene (WMD: ‒1.08 pg/ml, 95%CI: ‒2.03, ‒0.12, P = 0.027) led to a significant decrease in IL-6. The overall results supported possible protective effects of carotenoids on inflammatory biomarkers.

The effect of resveratrol on advanced glycation end products in diabetes mellitus: a systematic review.

Advanced glycation end products (AGEs) lead to chronic oxidative stress and inflammation, which in turn augment diabetes complications. Resveratrol plays a potential role in relation to diabetes due to improving of hyperglycemia, oxidative stress, and inflammation. The aim of this review was to evaluate the scientific literature to identify the impacts of resveratrol on the accumulation of AGEs. The literature was searched in the online databases, viz. PubMed, SCOPUS, Embase, ProQuest, and Google Scholar until May 2019. From a total of 338 retrieved articles, 10 papers were eligible for the present analysis. Except one clinical trial, all studies were conducted on animals. All the included studies, except one, showed inhibitory effects of resveratrol on the accumulation of AGE or receptor for AGEs. The findings indicate that resveratrol is a potential protective agent against the accumulation of AGEs. There is, however, the need for future studies to investigate this effect on human.

Chlorella vulgaris in combination with high intensity interval training in overweight and obese women: a randomized double-blind clinical trial.

BACKGROUND: Chlorella vulgaris (CV) as a multifunctional dietary supplement is known with lots of health benefits. It is possible that CV consumption along with high-intensity interval training (HIIT), a short period exercise is more beneficial. This investigation aimed to evaluate the effects of CV and/or HIIT on anthropometric parameters and cardiometabolic risk factors among overweight or obese women. METHODS: Present randomized double-blind clinical trial, included 46 women with overweight or obesity and randomly assigned them to four groups including CV, HIIT, CV+HIIT, and placebo. CV supplementation was 900 mg a day and HIIT program 3 sessions a week. Dietary intake, anthropometric assays and blood samples were taken at the commencement and completion of 8-week intervention. RESULTS: After 8 weeks, waist circumference (WC) significantly reduced in CV+HIIT group in comparison with placebo group. Significant decreases in triglycerides (TG) and low-density lipoprotein (LDL) cholesterol levels were found after CV supplementation and/or HIIT exercise in comparison with placebo group. A significant rise in high-density lipoprotein (HDL) cholesterol level was observed in HIIT and HIIT + CV groups in comparison with placebo group, however CV consumption failed to affect HDL cholesterol levels. CV and/or HIIT significantly lowered, visceral adiposity index (VAI), lipid accumulating product (LAP) and atherogenic index of plasma (AIP) in comparison with placebo. However, concurrent administration of CV and HII resulted in greater reduction in this indexes. Among glycemic indices a significant reduction in insulin resistance in CV+HIIT group compared with placebo group were seen. CONCLUSIONS: In conclusion, CV and HIIT could improve lipid profile and glycemic status in overweight and obese women.

The effect of green tea on prostate specific antigen (PSA): A systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Prostate cancer is a major malignancy, affecting men, worldwide. The protective effect of green tea consumption on prostate cancer has been reported in several studies; however, the findings are equivocal. OBJECTIVE: The aim of this study was to evaluate the effects of green tea on PSA level, by conducting a systematic review and meta-analysis of randomized controlled trials. METHODS: We searched online databases, including PubMed, Scopus, and Web of Science, up to 11 Aug 2020, to obtain relevant publications. The publication search was not limited by language or date. RESULTS: A total of 2488 records were identified in the systematic search; from these, seven were included in the meta-analysis. The overall analysis showed no significant changes in PSA levels in subjects treated with green tea, (WMD: ‒0.60 ng/mL; 95 % CI: ‒1.32, 0.12 ng/mL; P = 0.104, I2 = 93.80 %, P heterogeneity<0.001). Subgroup analysis based on geographical location showed that green tea significantly reduced PSA level in the USA population (WMD: ‒1.02 pg/mL, 95 % CI: ‒1.30, ‒0.73, P < 0.001) compared to non-USA populations (WMD: ‒0.22 pg/mL, 95 % CI: ‒0.95, 0.50, P = 0.539) (P < 0.001). CONCLUSION: The results of this review show that green tea has no significant effect on PSA level. However, due to the heterogeneity among studies more consistent clinical trials, with larger sample sizes are required.

Lutein supplementation combined with a low-calorie diet in middle-aged obese individuals: effects on anthropometric indices, body composition and metabolic parameters.

Lutein is considered as a major biologically active carotenoid, with potential benefits for obesity and cardiometabolic health. This double-blind, randomised controlled trial aimed to assess whether the consumption of lutein along with a low-calorie diet (LCD) can influence anthropometric indices, body composition and metabolic parameters in obese middle-aged individuals. After a 2-week run-in period with an LCD, forty-eight participants aged 45-65 years were randomly assigned to consume 20 mg/d lutein or placebo along with the LCD for 10 weeks. Dietary intake, anthropometric indices, body composition, lipid profile, glucose homoeostasis parameters, NEFA and appetite sensations were assessed at the beginning and end of the study. After 10 weeks, body weight and waist circumference significantly decreased in both groups, although between-group differences were not significant. There was more of a decrease in the percentage of body fat in the lutein group v. the placebo group. Moreover, the placebo group experienced a significant reduction in fat-free mass (FFM), whereas the lutein group preserved FFM during calorie restriction, although the between-group difference did not reach statistical significance. Visceral fat and serum levels of total cholesterol (TC) and LDL-cholesterol were significantly decreased only in the lutein group, with a statistically significant difference between the two arms only for TC. No significant changes were observed in the TAG, HDL-cholesterol, glucose homoeostasis parameters, NEFA and appetite sensations. Lutein supplementation in combination with an LCD could improve body composition and lipid profile in obese middle-aged individuals.

A comprehensive insight into the effect of glutamine supplementation on metabolic variables in diabetes mellitus: a systematic review.

Diabetes mellitus is one of the most important threats to human health in the twenty-first century. The use of complementary and alternative medicine to prevent, control, and reduce the complications of diabetes mellitus is increasing at present. Glutamine amino acid is known as a functional food. The purpose of this systematic review is to determine the potential role of glutamine supplementation on metabolic variables in diabetes mellitus. For this review, PubMed, SCOPUS, Embase, ProQuest, and Google Scholar databases were searched from inception through April 2020. All clinical trial and animal studies assessing the effects of glutamine on diabetes mellitus were eligible for inclusion. 19 studies of 1482 articles met the inclusion criteria. Of the 19 studies, nine studies reported a significant increase in serum GLP-1 levels. Also, eight studies showed reducing in serum levels of fasting blood sugar, four studies reducing in postprandial blood sugar, and triglyceride after glutamine supplementation. Although glutamine resulted in a significant increase in insulin production in seven studies, the findings on Hb-A1c levels were inconclusive. In addition to, despite of the results was promising for the effects of glutamine on weight changes, oxidative stress, and inflammation, more precise clinical trials are needed to obtain more accurate results. In conclusion, glutamine supplementation could improve glycemic control and levels of incretins (such as GLP-1 and GIP) in diabetes mellitus. However, more studies are needed for future studies.

The effect of vitamin d-calcium co-supplementation on inflammatory biomarkers: A systematic review and meta-analysis of randomized controlled trials.

Data on the effect of vitamin d-calcium co-supplementation on inflammatory biomarkers, compared to placebo or intake of calcium and vitamin D supplements alone, are conflicting. The current systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to summarize available findings on the effect of vitamin d-calcium co-supplementation on inflammatory biomarkers in adults. Online databases including PubMed, Scopus, ISI Web of Science and Google Scholar were searched using relevant keywords up to June 2019. We included RCTs investigating the effect of vitamin d-calcium co-supplementation, compared to placebo or intake of calcium and vitamin D supplements alone, on inflammatory biomarkers. In total, 8 RCTs that enrolled 706 participants, aged ≥18 years, were included. Pooling 9 effect sizes from 8 RCTs on C-reactive protein (CRP) levels revealed a significant reducing effect of vitamin d-calcium co-supplementation on serum CRP concentrations compared to placebo intake (WMD: -0.82, 95% CI: -1.56, -0.07 mg/L, P = 0.03). However, this beneficial effect became non-significant when compared to the intake of calcium and vitamin D supplements alone. Also, we found that the associations of vitamin d-calcium dosages and duration of intervention with the reduction in CRP concentrations were in a non-linear fashion. Combining 5 effect sizes for IL-6 and 3 effect sizes for TNF-α, we found no significant effect of joint calcium and vitamin D supplementation on serum concentrations of IL-6 (WMD: -1.45, 95% CI: -5.31, 2.41 pg/mL, P = 0.46) and TNF-α (WMD: -0.79, 95% CI: -2.19, 0.61 pg/mL, P = 0.26). We found a beneficial effect of vitamin d-calcium co-supplementation on serum CRP concentrations. However, such a beneficial effect was not seen for IL-6 and TNF-α concentrations.

The effects of taurine supplementation on oxidative stress indices and inflammation biomarkers in patients with type 2 diabetes: a randomized, double-blind, placebo-controlled trial.

BACKGROUND: Reduced serum level of taurine in type 2 diabetes mellitus (T2DM) was shown to be associated with the metabolic alterations and clinical complications of diabetes. Dietary supplementation with taurine may attenuate oxidative stress and inflammatory responses in T2DM as well as alleviate diabetes-induced complications. Hence, this study evaluated the effect of taurine supplementation on oxidative stress and inflammatory biomarkers in patients with T2DM. METHODS: Fifty patients with T2DM were randomly allocated to two groups to consume either taurine (containing 1000 mg taurine), or placebo (containing crystalline microcellulose) three times per day for 8 weeks. Anthropometric data, dietary intake, serum total antioxidant capacity (TAC), malondialdehyde (MDA), the activities of antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), serum levels of tumor necrosis factor alpha (TNF-α), interleukin 6 (IL-6) and high-sensitivity C-reactive protein (hs-CRP) were assessed before and after intervention. RESULTS: There was a significant increase in SOD (5.1%, p = 0.004) and CAT (4.22%, p = 0.001) after 8 weeks of taurine supplementation. In addition, serum levels of MDA (26.33%, p = 0.001), hs-CRP (16.01%, p = 0.001), and TNF-α (11.65%, p = 0.03) significantly decreased in the taurine group compared with baseline. Following treatment, the taurine group had fewer serum levels of MDA (p = 0.04), hs-CRP (p = 0.002) and TNF-α (p = 0.006) than the placebo group. Also, a significant increase was observed in SOD (p = 0.007), and CAT (p = 0.001) in the taurine group compared with the placebo group. There were no differences in the serum levels of IL-6 or TAC. CONCLUSIONS: The findings of this study showed that taurine supplementation improved some oxidative stress indices and inflammatory biomarkers in patients with T2DM.Trial registration The protocol of this clinical trial is registered with the Iranian Registry of Clinical Trials (http://www.IRCT.IR, identifier: IRCT20121028011288N16).

Quercetin and polycystic ovary syndrome, current evidence and future directions: a systematic review.

Polycystic ovary syndrome (PCOS) is a polygenic endocrine disorder and the most common gynecological endocrinopathy among reproductive-aged women. Current remedies are often used only to control its signs and symptoms, while they are not thoroughly able to prevent complications. Quercetin is an herbal bioactive flavonoid commonly used for the treatment of metabolic and inflammatory disorders. Thus, this systematic review was conducted to evaluate the efficacy of quercetin supplementation in subjects with PCOS. Databases until March 2019 were searched. All human clinical trials and animal models evaluating the effects of quercetin on PCOS women were included. Out of 253 articles identified in our search, 8 eligible articles (5 animal studies and 3 clinical trials) were reviewed. The majority of studies supported the beneficial effects of quercetin on the ovarian histomorphology, folliculogenesis, and luteinisation processes. The effects of quercetin on reducing the levels of testosterone, luteinizing hormone (LH), and insulin resistance were also reported. Although quercetin improved dyslipidemia, no significant effect was reported for weight loss. It is suggested that the benefits of quercetin may be more closely related to antioxidant and anti-inflammatory features of quercetin rather than weight-reducing effects. Therefore, this review article provides evidence that quercetin could be considered as a potential agent to attenuate PCOS complications. However, due to the paucity of high-quality clinical trials, further studies are needed.

Chamomile (Matricaria recutita L.) and diabetes mellitus, current knowledge and the way forward: A systematic review.

Chamomile, as a rich source of phenolic compounds and terpenoids, seems to be an effective approach in the management of chronic conditions such as diabetes mellitus. The aim of this systematic review was to evaluate evidence from animal and human studies of the effects of chamomile on metabolic risk markers and complications of diabetes mellitus. The literature search was conducted in PubMed, SCOPUS, Embase, ProQuest and Google Scholar electronic and were considered the articles published on April 2019. Original studies that investigated the effect of chamomile in diabetes mellitus which met the inclusion criteria were eligible. After screening 208 citations, 15 studies were included. The results of these studies demonstrated a significant effect of chamomile administration on metabolic profiles. All 12 studies that examined the impact of chamomile supplementation on glycemic control indicated this feature. Four of the five studies appraising the impact of chamomile on lipid profiles showed that it improved dyslipidemia. Six studies showed that chamomile markedly decreased oxidative stress particularly malondialdehyde. Altogether, four chamomile studies evaluating diabetes complications, including renal and hepatic profiles, found significant decreases compared to controls. These findings extend the novel functions of chamomile in the improvement of glycemic and lipid profiles and oxidative stress indicators in diabetes mellitus and related complications. In-depth studies focusing on underlying mechanisms are warranted to make useful conclusions.

Mechanistic insights into the effect of lutein on atherosclerosis, vascular dysfunction, and related risk factors: A systematic review of in vivo, ex vivo and in vitro studies.

Lutein is an essential carotenoid commonly consumed in the diet; however, its dietary intake does not usually reach the minimum recommended intake to decrease the incidence of chronic diseases. Experimental and epidemiological evidence suggests an anti-atherosclerotic effect for lutein-rich foods or lutein supplementation. This systematic review aimed to assess the mechanistic pathways of lutein in the prevention of atherosclerosis. Electronic databases, including PubMed, SCOPUS, ProQuest, Embase, and Google Scholar were searched to May 2019. Original studies published in English-language journals that investigated the effects of lutein on atherosclerosis and related risk factors, including lipid profile, hemodynamic, glycemic and inflammatory measurements, and endothelial function indices, were considered. Two reviewers independently extracted data on study characteristics, methods and outcomes. The review protocol has been registered at PROSPERO database of Systematic Reviews (registration number: CRD42019121381). A total of 5818 articles were found in the first phase of the search; from these, 19 met the inclusion criteria: 3 in vitro, 1 ex vivo, 11 animal, and 4 human studies. Nine of ten studies showed positive effects of lutein on endothelial function by reducing blood pressure, arterial thickness, monocyte migration, and vascular smooth muscle cell migration. Twelve studies examined the anti-inflammatory properties of lutein and found a significant decrease in proinflammatory cytokines. Although few studies investigated the anti-hyperlipidemic effects of lutein, three animal studies and one clinical trial found a beneficial effect of lutein on lipid profile. Evidence supports positive effects of lutein on atherosclerosis development and some common risk factors of atherosclerosis, including inflammation and endothelial dysfunction. Further studies focused on the effects of lutein on hyperglycemia, lipid profile, blood pressure and coagulation are required.