No abstract

Background Unsaturated fatty acids might be involved in the prevention and improvement of mental disorders, but the evidence on these associations has not been comprehensively assessed. Objective This umbrella review aimed to appraise the credibility of published evidence evaluating the associations between unsaturated fatty acids and mental disorders. Methods In this umbrella review, systematic reviews and meta-analyses of studies comparing unsaturated fatty acids (including supplementation, dietary intake and blood levels) in participants with mental disorders versus healthy individuals were included. We reanalyzed summary estimates, between-study heterogeneity, predictive intervals, publication bias, small-study effects, and excess significance bias for each meta-analysis. Results Ninety-five meta-analyses from 29 systematic reviews were included, encompassing 43 studies on supplementation interventions, 32 studies on dietary factors and 20 studies on blood biomarkers. Suggestive evidence was only observed for dietary intake, in which higher intake of fish was associated with reduced risk of depression (relative risk [RR]: 0.78; 95% CI: 0.69, 0.89) and Alzheimer's disease (RR: 0.74; 95% CI: 0.63, 0.87), and higher intake of total polyunsaturated fatty acids (PUFAs) might be associated with a lower risk of mild cognitive impairment (RR: 0.71; 95% CI: 0.61, 0.84). Evidence showed that PUFA supplementation was favorable but had weak credibility in anxiety, depression, attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder (ASD), dementia, mild cognitive impairment, Huntington's disease and schizophrenia (P random-effects: <0.001-0.040). There was also weak evidence on decreased circulating n-3 PUFAs among patients on risk of ADHD, ASD, bipolar disorder, and schizophrenia (P random-effects: <10–6-0.037). Conclusions Our results suggest that higher levels of unsaturated fatty acids may relieve symptoms or reduce the risk of various mental disorders; however, the strength of the associations and credibility of the evidence were generally weak. Future high-quality research is needed to identify whether PUFA interventions should be prioritized to alleviate mental disorders.

Purpose: The main objective of the study was to translate, validate, and compare the Chinese ORTO scales (ORTO-15 and ORTO-R). The secondary objective was to assess factors that may be related with risk of orthorexia nervosa (ON). Methods: Two cross-sectional surveys were conducted on March-to-June 2021 for ORTO-15) and April 2022 (ORTO-R). ORTO questionnaires were translated into Chinese using the forward–backward–forward method. Exploratory factor analysis, discriminant validity and confirmatory factor analysis (CFA) were used to examine the construct validity of the assessment questionnaires. The internal consistency was assessed by using the Cronbach alpha coefficient and the test-retest reliability. Multivariate linear regression analysis was used to explore potential impact factors related with ON scores. Results: Totally, 1289 and1084 eligible participants were included for the study of ORTO-15 and ORTO-R, with the mean age of 20.9±2.0 years and 21.0±2.3 years. The internal consistency of Chinese ORTO-15 scale and ORTO-R scale were both satisfactory (α=0.79, ICC=0.79; α=0.77, ICC=0.82). A two-factor solution of ORTO-R was characterized by acceptable goodness-of-fit, whereas the three-factor solution of ORTO-15 showed relatively poor fit. Multivariate linear regression indicated that physical activities and mental disorders were positively associated with ON risk assessed by both ORTO-R and ORTO-15. Conclusion: The Chinese ORTO-R scale were a more reliable tool to screen for ON tendencies than the Chinese version of ORTO-15. Mental disorders and physical activities might be associated with the increased ON risk.Level of evidence Level V (descriptive cross-sectional study).

Purpose: The main objective of the study was to translate, validate, and compare the Chinese ORTO scales (ORTO-15 and ORTO-R). The secondary objective was to assess factors that may be related with risk of orthorexia nervosa (ON). Methods: Two cross-sectional surveys were conducted on March-to-June 2021 for ORTO-15) and April 2022 (ORTO-R). ORTO questionnaires were translated into Chinese using the forward-backward-forward method. Exploratory factor analysis, discriminant validity and con rmatory factor analysis (CFA) were used to examine the construct validity of the assessment questionnaires. The internal consistency was assessed by using the Cronbach alpha coe cient and the test-retest reliability. Multivariate linear regression analysis was used to explore potential impact factors related with ON scores.Results: Totally, 1289 and1084 eligible participants were included for the study of ORTO-15 and ORTO-R, with the mean age of 20.9±2.0 years and 21.0±2.3 years. The internal consistency of Chinese ORTO-15 scale and ORTO-R scale were both satisfactory (α=0.79, ICC=0.79; α=0.77, ICC=0.82). A two-factor solution of ORTO-R was characterized by acceptable goodness-of-t, whereas the three-factor solution of ORTO-15 showed relatively poor t. Multivariate linear regression indicated that physical activities and mental disorders were positively associated with ON risk assessed by both ORTO-R and ORTO-15. Conclusion:The Chinese ORTO-R scale were a more reliable tool to screen for ON tendencies than the Chinese version of ORTO-15. Mental disorders and physical activities might be associated with the increased ON risk.Level of evidence Level V (descriptive cross-sectional study).