Effectiveness of Lifestyle-Based Approaches for Adults with Multiple Chemical Sensitivity. A Systematic Review

Background: Multiple Chemical Sensitivity is a complex and disabling condition characterized by a range of non-specific symptoms triggered by low-level exposure to common environmental chemicals. It often leads to significant impairment in quality of life, psychological well-being, and daily functioning. Non-pharmacological approaches—such as lifestyle modifications and psychological interventions—are frequently used in clinical practice, but their effectiveness remains uncertain. Objective: To evaluate the effectiveness of lifestyle-based interventions in improving outcomes in adults with MCS. Methods: A systematic review was conducted following PRISMA guidelines (PROSPERO: CRD420251013537). Searches were performed in MEDLINE, Google Scholar, CINAHL, and ResearchGate from March to April, 2025. Eligible studies included adults (≥18 years) with a verified diagnosis of Multiple Chemical Sensitivity, reporting outcomes such as stress perception, anxiety, depressive symptoms, or quality of life. Methodological quality and risk of bias were assessed using PEDro, NIH, CEBMa, and RoB 2.0 tools. Results: Twelve studies (n = 378) were included. Cognitive and behavioral therapies consistently demonstrated reductions in symptom severity, maladaptive thought patterns, and functional limitations. Mindfulness-based stress reduction showed beneficial effects, while other mindfulness-based approaches were less conclusive. Exposure-based therapies helped improve chemical tolerance and reduce avoidance behaviors. Electromagnetic and biomedical interventions showed preliminary but limited evidence of effectiveness, and aromatherapy was well tolerated though minimally effective. Conclusions:Among lifestyle-based interventions, cognitive and behavioral therapies appear most effective for managing symptoms of Multiple Chemical Sensitivity. Nevertheless, heterogeneity in study design, intervention protocols, and outcome measures limits the generalizability of findings.