title: White rice intake and incidence of type-2 diabetes: analysis of two prospective cohort studies from Iran.
abstract: Refined grains and white rice have been associated with elevated risk of type 2 diabetes mellitus (T2DM). In this study, we sought to quantify the effect of white rice intake on incident T2DM in two prospective population-based cohort studies from Iran, where white rice is one of the main staple.
  
  
  
  We used follow-up data from 9,182 participants from Golestan Cohort Study (GCS, 2004-2007, conducted mainly in rural areas) and 2,173 from Tehran Lipid and Glucose Study (TLGS, 2004-2006) who did not have T2DM and other chronic diseases at baseline. Diet was assessed using validated food frequency questionnaires. Multivariable logistic regression models were used to estimate adjusted odds ratios (ORs) for incident T2DM.
  
  
  
  We documented 902 new cases of T2DM in GCS and 81 in TLGS. Age-standardized cumulative incidence of T2DM was 9.9% in Golestan and 8.0% in Tehran. Daily white rice intake was significantly higher among residents of Tehran compared to Golestan (median daily intake: 250 vs. 120 grams; P-value < 0.001). After adjustment for potential confounders, there was no significant association between daily white rice intake and incident T2DM in GCS. In TLGS, the adjusted OR (95% confidence interval (CI)) was 2.1 (1.1, 3.9) comparing participants with daily white rice intake of >250 grams/day to those with <250.
  
  
  
  We observed an increased lieklihood of T2DM associated with high white rice intake among residents of Tehran and no association in Golestan. Our findings, if further supported by other studies, have important public health implications especially for countries where white rice is a major staple and diabetes is increasing rapidly incidence is high. Further research is needed to investigate lack of an association between lower levels of white rice intake and T2DM.
authors.affiliation: Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, 14117, Iran.|Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, 21205, USA.
authors.forename: Asieh
authors.initials: A
authors.lastname: Golozar
authors.affiliation: Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, 17413, Iran.
authors.forename: Davood
authors.initials: D
authors.lastname: Khalili
authors.affiliation: Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, 14117, Iran.|Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, 20850, USA.
authors.forename: Arash
authors.initials: A
authors.lastname: Etemadi
authors.affiliation: Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, 14117, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Poustchi
authors.affiliation: Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, 14117, Iran.
authors.forename: Akbar
authors.initials: A
authors.lastname: Fazeltabar
authors.affiliation: Nutrition and Endocrine Research Center/Obesity Research Center,Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Science, Tehran, 17413, Iran.
authors.forename: Firoozeh
authors.initials: F
authors.lastname: Hosseini
authors.affiliation: School of Community Health and Policy, Morgan State University, Baltimore, 21251, MD, USA.
authors.forename: Farin
authors.initials: F
authors.lastname: Kamangar
authors.affiliation: Golestan Research Center of Gastroenterology and Hepatology, Golestan University of Medical Sciences, Gorgan, Golestan, 0619, Iran.
authors.forename: Masoud
authors.initials: M
authors.lastname: Khoshnia
authors.affiliation: Surveillance and Health Services Research, American Cancer Society, Atlanta, 30303, Georgia, USA.
authors.forename: Farhad
authors.initials: F
authors.lastname: Islami
authors.affiliation: Prevention of Metabolic Disorders Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, 17413, Iran.
authors.forename: Farzad
authors.initials: F
authors.lastname: Hadaegh
authors.affiliation: International Agency for Research on Cancer, Lyon, 69008, France.
authors.forename: Paul
authors.initials: P
authors.lastname: Brennan
authors.affiliation: The Tisch Cancer Institute and Institute for Translational Epidemiology, Mount Sinai School of Medicine, New York, 10029, New York, USA.
authors.forename: Paolo
authors.initials: P
authors.lastname: Boffetta
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, 20850, USA.
authors.forename: Christian C
authors.initials: CC
authors.lastname: Abnet
authors.affiliation: Division of Cancer Epidemiology and Genetics, National Cancer Institute, Bethesda, MD, 20850, USA.
authors.forename: Sanford M
authors.initials: SM
authors.lastname: Dawsey
authors.affiliation: Endocrine Research Center, Research Institute for Endocrine Sciences, Shahid Beheshti University of Medical Sciences, Tehran, 17413, Tehran, Iran.
authors.forename: Fereidoun
authors.initials: F
authors.lastname: Azizi
authors.affiliation: Digestive Disease Research Institute, Shariati Hospital, Tehran University of Medical Sciences, Tehran, 14117, Iran.
authors.forename: Reza
authors.initials: R
authors.lastname: Malekzadeh
authors.affiliation: Department of Global Health and Population, Harvard School of Public Health, 677 Huntington Avenue, Bldg 1, Boston, 02115, MA, USA. gdanaei@hsph.harvard.edu.|Department of Epidemiology, Harvard School of Public Health, 677 Huntington Avenue, Bldg 1, Boston, MA, 02115, USA. gdanaei@hsph.harvard.edu.|SAPHIR, the Scientific Association for Public Health in Iran , Boston, 02132, USA. gdanaei@hsph.harvard.edu.
authors.forename: Goodarz
authors.initials: G
authors.lastname: Danaei
mesh_terms: D000328:Adult; D000368:Aged; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology*; D004032:Diet / Q000706:statistics & numerical data; D005260:Female; D005518:Food Preferences; D006801:Humans; D015994:Incidence; D007492:Iran / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D012275:Oryza; D011446:Prospective Studies; D012307:Risk Factors
keywords: Diet; Incident type 2 diabetes; Low- and middle-income countries; Refined carbohydrates; White rice