Volatile organic compounds exposure and all health outcomes: An umbrella review and evidence map.

Comorbid clinical and biomarker outcomes in patients with obsessive-compulsive disorder: An umbrella review and evidence map.

Background and Aims: The dietary inflammatory index (DII) is associated with non-communicable disease. We conducted an umbrella review to systematically evaluate meta-analyses of observational studies on DII and diverse health outcomes.Methods: We comprehensively searched the PubMed, Web of Science, and Embase databases to identify related systematic reviews and meta-analyses of observational studies. Those investigating the association between DII and a wide range of health outcomes in humans were eligible for inclusion. For each meta-analysis, we estimated the summary effect size by using fixed and random effects models, the 95% confidence interval, and the 95% prediction interval. We assessed heterogeneity, evidence of small-study effects, and excess significance bias.Results: The umbrella review identified 35 meta-analyses assessing associations between DII and various health outcomes: cancer (n = 24), mortality (n = 4), metabolic (n = 4), and other (n = 3). The methodological quality was high or moderate. Of the 35 meta-analyses, we observed highly suggestive evidence for harmful associations between digestive tract cancer, colorectal cancer, overall cancer, pharyngeal cancer, UADT cancer, and CVD mortality. Moreover, 11 harmful associations showed suggestive evidence: hormone-dependent cancer, rectal cancer, colon cancer, breast and prostate cancer, gynecological cancer, breast cancer, ovarian cancer, colorectal cancer, prostate cancer, all-cause mortality, and depression.Conclusion: DII is likely to be associated with harmful effects in multiple health outcomes. Robust randomized controlled trials are warranted to understand whether the observed results are causal.Systematic Review Registration: CRD42021218361

Exposure to volatile organic compounds may be associated with oxidative DNA damage-mediated childhood asthma

Exposure to volatile organic compounds and growth indicators in adolescents: Unveiling the association and potential intervention strategies

Associations between VOCs and childhood asthma in Shanghai, China: Impacts of daily behaviors

Dietary protein and multiple health outcomes: An umbrella review of systematic reviews and meta-analyses of observational studies

In-situ real-time monitoring of volatile organic compound (VOC) exposure and heart rate variability (HRV) were conducted for eight multiple chemical sensitivity (MCS) patients using a VOC monitor, a Holter monitor, and a time-activity questionnaire for 24 h to identify the relationship between VOC exposure, biological effects, and subjective symptoms in actual life. The results revealed no significantly different parameters for averaged values such as VOC concentration, HF (high frequency), and LF (low frequency) to HF ratio compared with previous data from healthy subjects (Int. J. Environ. Res. Public Health 2010, 7, 4127–4138). Significant negative correlations for four subjects were observed between HF and amounts of VOC change. These results suggest that some patients show inhibition of parasympathetic activities along with VOC exposure as observed in healthy subjects. Comparing the parameters during subjective symptoms and normal condition, VOC concentration and/or VOC change were high except for one subject. HF values were low for five subjects during subjective symptoms. Examining the time-series data for VOC exposure and HF of each subject showed that the subjective symptoms, VOC exposure, and HF seemed well related in some symptoms. Based on these characteristics, prevention measures of symptoms for each subject may be proposed.

Background and Aims: The associations between dietary carbohydrate and diverse health outcomes remain controversial and confusing. To summarize the existing evidence of the association between dietary carbohydrate intake and diverse health outcomes and to evaluate the credibility of these sources of evidence. We performed this umbrella review of evidence from meta-analyses of observational studies.Methods: PubMed, Embase, Web of Science databases, and manual screening of references up to July 2020 were searched. Systematic reviews with meta-analyses of observational studies in humans investigating the association between dietary carbohydrate intake and multiple health outcomes were identified. We assessed the evidence levels by using summary effect sizes, 95% prediction intervals, between-study heterogeneity, evidence of small-study effects, and evidence of excess significance bias for each meta-analysis.Results: We included 43 meta-analyses of observational research studies with 23 health outcomes, including cancer (n = 26), mortality (n = 4), metabolic diseases (n = 4), digestive system outcomes (n = 3), and other outcomes [coronary heart disease (n = 2), stroke (n = 1), Parkinson's disease (n = 1), and bone fracture (n = 2)]. This umbrella review summarized 281 individual studies with 13,164,365 participants. Highly suggestive evidence of an association between dietary carbohydrate intake and metabolic syndrome was observed with adjusted summary odds ratio of 1.25 [95% confidence interval (CI) 1.15–1.37]. The suggestive evidences were observed in associations of carbohydrate consumption with esophageal adenocarcinoma (0.57, 95% CI = 0.42–0.78) and all-cause mortality (adjusted summary hazard ratio 1.19, 95% CI = 1.09–1.30).Conclusions: Despite the fact that numerous systematic reviews and meta-analyses have explored the relationship between carbohydrate intake and diverse health outcomes, there is no convincing evidence of a clear role of carbohydrate intake. However, there is highly suggestive evidence suggested carbohydrate intake is associated with high risk of metabolic syndrome, suggestive evidence found its association with increased risk of all-cause mortality and decreased risk of esophageal adenocarcinoma.Systematic Review Registration: CRD42020197424.

Elevated levels of homocysteine (Hcy) are associated with various health outcomes. We aimed to systematically assess the credibility and certainty of evidence of associations of Hcy and Hcy-lowering therapies with various health outcomes. We retrieved observational meta-analyses examining the associations between Hcy and health outcomes, interventional meta-analyses investigating health outcomes related to Hcy-lowering treatments, and Mendelian randomization (MR) studies exploring the causal associations of Hcy with health outcomes to perform an umbrella review. A total of 135 observational meta-analyses, 106 MR studies, and 26 interventional meta-analyses were included. Among observational studies, 10 associations of diseases/outcomes were classified as highly suggestive; only 1 outcome (digestive tract cancer) was supported by convincing evidence (class I; odd ratio = 1.27, 95% confidence interval = 1.16, 1.40; P = 6.79 × 10-7; I2 = 0, 95% prediction interval excluding null, >1000 cases; P > 0.1 for tests of both small-study effects and excess significance bias). In MR studies, 5 outcomes associated with Hcy presented robust evidence (P < 0.01, power >80%). Among 25 outcomes explored by both observational meta-analyses and MR studies, 7 had consistent results, indicating that elevated Hcy is causally associated with an increased risk of these outcomes. The 3 types of studies collectively suggested that the association of stroke with Hcy was supported by observational studies, causally by MR studies, and further validated by intervention meta-analyses showing that Hcy-lowering with folic acid significantly reduced risk of stroke. For dementia and colorectal cancer, Hcy was significantly associated in meta-analyses of observational studies and folic acid decreased disease risks in interventional meta-analyses. The current umbrella review indicates that convincing evidence for a definitive role of Hcy exposure solely exists in the context of digestive tract cancer excluding bias; however, Hcy may not be causal for this disease. All the 3 types of studies collectively support that Hcy is a key causal risk factor, and Hcy-lowering (specifically with folic acid) may serve as an effective intervention for stroke.This trial was registered at PROSPERO as CRD42024541335.

Background: Hairdressers are routinely exposed to volatile organic compounds (VOCs) linked to adverse health effects. Over 32% of U.S. hairdressers are women of color who may experience disproportionate VOC exposures from their occupational and personal use of products formulated for ethnic (Black/Latina) clientele. While these exposures may reflect potential health disparities, little is known about VOC exposures and their determinants in this worker population.Objective: To characterize concentrations of urinary VOC (UVOC) exposure biomarkers and their determinants among female hairdressers primarily serving an ethnic clientele.Methods: We recruited 23 minority female hairdressers predominantly serving an ethnic clientele, and 17 office workers in the Maryland/DC metro area. We quantified concentrations of 28 biomarkers, representing 20 VOC parent compounds in end-of-shift urine samples, using isotope dilution ultra-performance liquid chromatography-tandem mass spectrometry. UVOC concentrations in hairdressers were compared to those among office workers and women in the U.S. general population (NHANES). We administered questionnaires to capture demographics and workplace behaviors.Results: The majority of hairdressers (65%) were black with a mean age of 40 years. Half of office workers were black with a mean age of 34 years. Geometric mean concentrations for 26 of the 28 UVOCs were higher in hairdressers than office workers, with statistically significant concentration differences observed for 10 biomarkers (p&lt;0.05). Also, geometric mean concentrations for 21 of 23 biomarkers quantified by both NHANES and our study, were between 1.5-3.7 times higher in hairdressers than women participating in NHANES. Salon services including semi-permanent hair coloring and hair extensions with glue, were associated with higher concentrations of toluene, xylene and acrylonitrile.Conclusions: Our work is among the first to characterize VOC exposures among minority female hairdressers serving an ethnic clientele. Larger studies are warranted to further examine determinants of VOC exposures and associated adverse health effects among this disparately exposed population.

Vitamin D and Multiple Health Outcomes: An Umbrella Review of Observational Studies, Randomized Controlled Trials, and Mendelian Randomization Studies

Numerous workplaces handle solvent-based products, exposing workers to complex and changing mixtures of volatile organic compounds (VOCs), many of which are neurotoxic. In this commentary, we highlight key findings from research on VOC exposures in the workplace and their consequences for the central nervous system (CNS). We also provide a case study of nail salons as exposure sites. A few nail salon studies have suggested adverse health effects at low-level complex mixture VOC exposures, including significant neurological symptoms such as headaches, dizziness, difficulty concentrating, and memory loss, even when VOC exposures are below occupational exposure limits. Limited evidence specific to the health effects on nail salon workers relies on self-reported health outcomes or broad tests of mental abilities, using self-reported exposure surrogates that can lead to exposure misclassification. Unfortunately, assessing risk one chemical at a time with its respective threshold limit-or even using the traditional industrial hygiene mixtures approach-has not been sufficient to identify key VOCs or groups of VOCs most strongly linked to CNS health outcomes in nail salon workers. Scientific methodology used to understand low-level VOC mixture health effects in this population must evolve to measure chemical mixtures more easily and accurately, employ sensitive and culturally appropriate methods to assess neurological health effects, use advanced statistical methods, and develop strategies to prevent these debilitating health outcomes. Research evaluating possible health consequences at low exposure levels is still critical for guaranteeing the health of workers exposed to VOC, even with ongoing safer alternative substitution efforts.

Multiple meta-analyses (MAs) have demonstrated that six pharmacotherapies, including orlistat, liraglutide, phentermine/topiramate, naltrexone/bupropion, semaglutide, and tirzepatide, improve weight loss and weight maintenance. However, few studies have synthesized and evaluated the quality of this evidence. To identify the relevant MAs of randomized clinical trials (RCTs) that explored the association between the six pharmacotherapies and obesity-related health outcomes and adverse events (AEs). A comprehensive search was conducted across PubMed, Embase, Cochrane Library, and Web of Science from database inception up to January 2024. We calculated the effect size as the mean difference and risk ratio using the random-effects model. The quality of MAs was evaluated using "A Measurement Tool to Assess Systematic Reviews 2". Sixteen MAs comprising 235 RCTs that described 115 unique associations between the six pharmacotherapies and various health outcomes were included. Overall, 101 statistically significant associations (88%) had beneficial outcomes on body weight, weight loss, waist circumference, body mass index, total cholesterol, triglycerides, both low-density and high-density lipoprotein cholesterol, blood pressure, and glycemic profile. The pharmacotherapies were associated with significant weight loss and partial improvements in the lipid profile, blood pressure, and glycemic control among individuals with overweight or obesity. Notable AEs were associated with liraglutide, naltrexone/bupropion, semaglutide, and orlistat. The methodological quality of the included MAs requires improvement. This umbrella review identified significant beneficial associations between pharmacotherapies and anthropometric measures, lipid profile, blood pressure, glycemic profile, and quality-of-life outcomes in individuals with overweight or obesity. In addition, the umbrella review highlighted safety considerations. The findings affirm the efficacy of the six pharmacotherapies in promoting weight loss in this demographic. Further clinical trials with long-term follow-up are essential to evaluate the effects of these pharmacotherapies on clinical outcomes, including cancer, cardiovascular events, and mortality.

IntroductionCleaning products are complex mixtures of chemicals, and their use is associated with elevated prevalence of asthma symptoms among healthcare workers. In this study, we evaluate the effects of cleaning...

Ultra-processed foods (UPFs) now contribute a substantial share of total energy intake. A growing body of evidence has linked UPF consumption to adverse health outcomes, but existing umbrella reviews are mainly restricted to studies published before mid-2023 and have seldom rigorously examined the shape of dose-response relationships, evaluating both linearity and nonlinearity. The aim of this study was to synthesize updated meta-analytic evidence on associations between UPF consumption and major health outcomes in children and adults. A narrative umbrella review synthesized meta-analyses of studies published through December 9, 2025. Outcomes included obesity, type 2 diabetes (T2D), cardio-cerebrovascular diseases (CCVDs), nonalcoholic fatty liver disease (NAFLD), cognition, mental health (anxiety and depression), dental health, cancer, and all-cause mortality. For each outcome, a lead meta-analysis was selected by comprehensiveness, recency, and methodological quality (separately for children and adults when feasible). Methodological quality was assessed using a ROBIS (Risk of Bias Assessment Tool for Systematic Reviews)-adapted tool. Certainty of evidence was rated with GRADE (Grading of Recommendations, Assessment, Development and Evaluation). Twelve lead meta-analyses (mainly from observational studies) covering 13 outcomes were identified (4/13 in children). Across all but 1 outcome, higher (vs lower) UPF consumption was associated with increased risk (see graphical abstract). Dose-response evidence indicated a 10% higher risk per 10% increase in UPF intake for T2D, a curvilinear risk increase for CCVDs, and no significant association for NAFLD; for other outcomes, rigorous dose-response analyses were lacking. Certainty of evidence was high for 1 outcome, moderate for 6, and low for 6 other outcomes. This updated umbrella review confirmed harmful associations of UPFs with multiple health outcomes, and added insights on children's health, cognition, dental health, CCVDs, and dose-response. Despite remaining methodological gaps (including observational-based and nonrigorous dose-response analyses), current evidence supports population-wide strategies to reduce UPF intake. Systematic Review Registration: PROSPERO registration no. CRD420251230427.