Diet and related lifestyle, lung function and chronic obstructive pulmonary disease in Middle Eastern and African countries: A systematic review

Background Diet and lifestyle may modulate lung function and COPD but most evidence comes from richer countries. We have systematically investigated the evidence on the association between diet and lung function in Africa and the Middle East, where the burden of COPD is increasing. Methods Protocol-driven strategies were used to search the Cochrane library, MEDLINE, and Web of Science for all studies published up to September 2013 on any dietary or related lifestyle exposures and lung function (LF) or COPD. We used the PRISMA (Preferred Reporting Items for Systematic Reviews (SR) and Meta-Analyses) guidelines for data extraction. Quality of eligible papers was assessed using the Critical Appraisal Skills Programme (CASP). Results 782 potentially relevant studies were identified. 631 titles and abstracts were examined for eligibility after eliminating 151 duplicate studies. 22 studies met the inclusion criteria: 16 cross-sectional, 3 case-control, and 3 interventions. 18 were on lung function and 4 on COPD. Exposures were limited to vitamins A, C and E, omega 3 fatty acids, use of nutrient supplements, obesity, body fat, and prolonged periods of fasting (Ramadan). The samples studied were mostly unrepresentative of the general population. Most studies shown a positive association between antioxidant nutrients and LF but data were too heterogeneous to carry out meta-analyses. Conclusion This first systematic review on diet and related risk factors for lung function and COPD in Africa and the Middle East highlights the need for improved studies in the general population of this region. ERS fellowshipSTRTF - 2013-3077 supported Dr El-Rhazi.