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Clinical trial studies revealed conflicting results on the effect of Ashwagandha extract on anxiety and stress. Therefore, we aimed to evaluate the effect of Ashwagandha supplementation on anxiety as well as stress. A systematic search was performed in PubMed/Medline, Scopus, and Google Scholar from inception until December 2021.We included randomized clinical trials (RCTs) that investigate the effect of Ashwagandha extract on anxiety and stress. The overall effect size was pooled by randomeffects model and the standardized mean difference (SMD) and 95% confidence interval (CIs) for outcomes were applied. Overall, 12 eligible papers with a total sample size of 1,002 participants and age range between 25 and 48 years were included in the current systematic review and meta-analysis. We found that Ashwagandha supplementation significantly reduced anxiety (SMD: À1.55, 95% CI: À2.37, À0.74; p = .005; I 2 = 93.8%) and stress level (SMD: À1.75; 95% CI: À2.29, À1.22; p = .005; I 2 = 83.1%) compared to the placebo. Additionally, the non-linear dose-response analysis indicated a favorable effect of Ashwagandha supplementation on anxiety until 12,000 mg/d and stress at dose of 300-600 mg/d. Finally, we identified that the certainty of the evidence was low for both outcomes. The current systematic review and dose-response meta-analysis of RCTs revealed a beneficial effect in both stress and anxiety following Ashwagandha supplementation. However, further highquality studies are needed to firmly establish the clinical efficacy of the plant.

We conducted the present systematic review and meta-analysis to evaluate the association of total protein, animal protein and animal protein sources with risk of kidney stones in the general population. A literature search was performed on PubMed/Medline, Scopus and EMBASE up to July 2021. We assessed the credibility of evidence based on NutriGrade scoring system. A total of 14 prospective cohort studies were included. A positive association was observed between higher intake of non-dairy animal protein (RR: 1.11, 95%CI: 1.03, 1.20; I2 = 0%, n = 4), total meat and meat products (RR: 1.22, 95%CI: 1.09, 1.38; I2 = 13%, n = 3), and processed meat (RR: 1.29, 95%CI: 1.10, 1.51; I2 = 0%, n = 2) with risk of kidney stones. There was an inverse association between higher intake of dairy protein and risk of kidney stones (RR: 0.91, 95%CI: 0.84, 0.99; I2 = 0%, n = 4). Moreover, each 100 gram increment of red meat intake was significantly associated with increased risk of kidney stones (RR: 1.39, 95% CI: 1.13, 1.71). According to NutriGrade scoring system, the credibility of evidence for most of the exposures was rated as low. We found some kind of publication bias in the association of animal protein intake and risk of kidney stones, according to Egger's and Begg's tests. In the sensitivity analysis of processed meat as well as dairy consumption with risk of kidney stones, we observed in each individual analysis, one study changed the overall estimate. Further observational studies are needed to confirm present results.

Some studies suggested the effects of inflammatory cytokines in reducing muscle mass and muscle strength and, performance. This study aimed to compare pro-inflammatory cytokines in sarcopenic and non-sarcopenic subjects. 120 men and women were selected out from the cross-sectional study ‘sarcopenia and its determinants among Iranian elders’ (SARIR). Sarcopenia was defined based on the first ‘European Working Group on sarcopenia in older people’ (EWGSOP1) guidelines. A fasting blood sample was taken from each participant to measure serum high-sensitivity C-reactive protein (hs-CRP), Interleukin 6 (IL-6), and tumor necrosis factor α (TNFα). A total of 120 participants were included in this study. Mean age was 66.7 ± 7.7 years and mean body mass index (BMI) was 27.3 ± 4.2 kg/m2. Forty participants had the criteria of EWGSOP1 sarcopenia. A statistically significant difference was seen between normal and abnormal groups of muscle strength in hs-CRP (P-value = 0.04). Furthermore, we did not observe any remarkable association between inflammatory biomarkers including IL-6 (OR 1.15; 95% CI 0.31–4.28), TNF-α (OR 0.68; 95% CI 0.17–2.77), and hs-CRP (OR 2.39; 95% CI 0.87–6.55) and the presence of sarcopenia even after controlling for plausible confounders. We found that inflammatory biomarkers level was not associated with odds of sarcopenia. The lack of correlation between inflammatory cytokines and sarcopenia could be due to the participants’ age and genetics. Future studies are required to confirm these findings.

Context Current findings about the differential effects of various sources of dietary animal protein on the risk of neurodegenerative diseases are contradictory. Objective The current meta-analysis was conducted to investigate the associations between intake of dietary animal protein sources and the risk of neurodegenerative diseases. Data Sources PubMed, Scopus, Web of Science, and Google Scholar databases were searched systematically until October 2021. Data Extraction Prospective cohort studies exploring the association between consumption of animal protein sources and risk of neurodegenerative diseases in the general population were included. Among 10 571 identified studies, 33 prospective cohort studies met the eligibility criteria. Data Analysis Dietary fish consumption was associated with a reduced risk of Alzheimer’s disease (RR = 0.75; 95%CI, 0.57–0.97), dementia (RR = 0.84; 95%CI, 0.75–0.93), and cognitive impairment (RR = 0.85; 95%CI, 0.81–0.95). The risk of developing Parkinson’s disease was significantly higher among those in the highest vs the lowest intake categories of total dairy (RR = 1.49; 95%CI, 1.06–2.10) and milk (RR = 1.40; 95%CI, 1.13–1.73). Moreover, dietary intake of total dairy (RR = 0.89; 95%CI, 0.80–0.99), total meat (RR = 0.72; 95%CI, 0.57–0.90), and poultry (RR = 0.82; 95%CI, 0.68–0.99) was significantly associated with a lower risk of cognitive impairment. A linear dose-response meta-analysis revealed that each 200-g increase in total daily dairy intake was associated with an 11% higher risk of Parkinson’s disease and a 12% lower risk of cognitive impairment. Furthermore, there was a strong linear association between fish consumption and reduced risk of dementia. Conclusion Dairy consumption is associated with an increased risk of Parkinson’s disease, but a higher intake of fish may be associated with lower risk of neurodegenerative disease. Future well-controlled, randomized clinical trials are essential to validate the present findings. Systematic Review Registration PROSPERO registration no. CRD42021281887.