Speech and Language Pathology, School of Rehabilitation Sciences, Tehran University of Medical Sciences, Tehran, Iran
Research Committee and Department of Speech Therapy, School of Rehabilitation Sciences, Isfahan University of Medical Sciences, Isfahan, Iran
Department of ENT, Tehran University of Medical Sciences, Tehran, Iran
Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
Mt Kuring-Gai Medical Centre, Suite 5,6, 757 Pacific Hwy, Mount Kuring-Gai NSW 2080
Department of Statistics and Epidemiology, Faculty of Health, Tabriz University of Medical Sciences, Tabriz, Iran.
Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz, Iran,
Indigenous & Global Health Research Group, Department of Medicine, University of Alberta, Edmonton, Canada.,
Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada.
Background: The relationship between dietary pattern and the risk of chronic obstructive pulmonary disease (COPD) has been described; however, the exclusive role of dietary factors remains controversial. Hence, we conducted this systematic meta-analysis to clarify the role of some nutrients and antioxidant vitamins in the risk of COPD.
Materials and Methods: PubMed, Embase, and Scopus databases were searched for studies evaluating the associations between COPD outcome measures, symptoms, and mortality, and intake of fruits and vegetables, fiber, fish, n-3 or n-6 fatty acids, and antioxidant vitamins in adults. The random-effect model meta-analyses were used to pool the results.
Results: Ten cohort, six case-control, and 20 cross-sectional studies were identified. The pooled relative risks (RRs) of the COPD and confidence intervals (CIs) for the highest intake group compared with the lowest intake group were 0.74 (95% CI: 0.65-0.85) for fruit, 0.65 (95% CI: 0.55-0.78) for dietary fiber, 0.71 (95% CI: 0.58-0.85) for fish, and 0.89 (95% CI: 0.76-0.99) for vitamin C. No association was observed between the risk of COPD and the intake of vegetables, n-3 fatty acids, vitamin E, and β-carotene; however, it was associated with n-6 fatty acids 1.06 (95% CI: 0.87-1.30).
Conclusion: The results suggested that a higher intake of fruits, probably dietary fiber, and fish reduce the risk of COPD.