High prevalence of nonalcoholic fatty liver disease in the middle east: Lifestyle and dietary habits

Potential conflict of interest: Nothing to report. To the Editor: I read with interest the recently published study by Younossi and colleagues demonstrating a steady rise in worldwide prevalence of nonalcoholic fatty liver disease (NAFLD).1 The Middle East has the highest prevalence rate of NAFLD among all other areas of the world. Three studies from Middle Eastern countries were included in this report. However, these studies are not concordant in terms of study design and population. The Iranian study which we performed dated back to 5 years ago and was conducted in a small town in Fars province.2 It should be noted that the study population was more similar to rural areas in terms of lifestyle. They had dietary habits that included less fast food and fewer foods enriched with saturated fatty acids as well as more daily physical activity. Therefore, the higher prevalence in urban areas with a more industrialized lifestyle is predictable and not surprising. The prevalence of NAFLD in urban areas was nearly 10% higher than that in rural areas in another Iranian study.3 The mentioned Turkish study was not a population‐based study. The study participants had been selected form outpatients returning to gastroenterology and internal medicine clinics affiliated to a university hospital. Therefore, the high reported prevalence of NAFLD (55%) in the study cannot be extrapolated to the general population.4 The study population in the third report was limited to participants aged 24‐70 years, which is different from the two other studies included in the meta‐analysis.5 Furthermore, it should be emphasized that estimation of NAFLD prevalence was not the primary aim in any of these three studies. On the other hand, NAFLD was diagnosed using ultrasound criteria in these studies, and there is still a lack of data regarding biopsy‐proven NAFLD including nonalcoholic steatohepatitis in the Middle East. Regardless of the designs of these studies, the change in dietary habits and lifestyle in Middle Eastern countries may be one of the main reasons for the high prevalence of NAFLD in this region. A recent review article showed that food and energy availability has increased over the past five decades in the Middle East. This increase in energy has been derived mainly from meat and vegetable oils, while the proportion of energy from fruits has decreased significantly.6 These changes have led to emerging epidemics of obesity and metabolic syndrome in this region and a subsequent rise in NAFLD. Therefore, we still need studies to focus specifically on the epidemiological aspects of NAFLD in Middle Eastern countries.