title: Red meat consumption and risk of type 2 diabetes: 3 cohorts of US adults and an updated meta-analysis.
abstract: BACKGROUND
  The relation between consumption of different types of red meats and risk of type 2 diabetes (T2D) remains uncertain.
  
  
  OBJECTIVE
  We evaluated the association between unprocessed and processed red meat consumption and incident T2D in US adults.
  
  
  METHODS
  We followed 37,083 men in the Health Professionals Follow-Up Study (1986-2006), 79,570 women in the Nurses' Health Study I (1980-2008), and 87,504 women in the Nurses' Health Study II (1991-2005). Diet was assessed by validated food-frequency questionnaires, and data were updated every 4 y. Incident T2D was confirmed by a validated supplementary questionnaire.
  
  
  RESULTS
  During 4,033,322 person-years of follow-up, we documented 13,759 incident T2D cases. After adjustment for age, BMI, and other lifestyle and dietary risk factors, both unprocessed and processed red meat intakes were positively associated with T2D risk in each cohort (all P-trend <0.001). The pooled HRs (95% CIs) for a one serving/d increase in unprocessed, processed, and total red meat consumption were 1.12 (1.08, 1.16), 1.32 (1.25, 1.40), and 1.14 (1.10, 1.18), respectively. The results were confirmed by a meta-analysis (442,101 participants and 28,228 diabetes cases): the RRs (95% CIs) were 1.19 (1.04, 1.37) and 1.51 (1.25, 1.83) for 100 g unprocessed red meat/d and for 50 g processed red meat/d, respectively. We estimated that substitutions of one serving of nuts, low-fat dairy, and whole grains per day for one serving of red meat per day were associated with a 16-35% lower risk of T2D.
  
  
  CONCLUSIONS
  Our results suggest that red meat consumption, particularly processed red meat, is associated with an increased risk of T2D.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, MA 02115, USA.
authors.forename: An
authors.initials: A
authors.lastname: Pan
authors.forename: Qi
authors.initials: Q
authors.lastname: Sun
authors.forename: Adam M
authors.initials: AM
authors.lastname: Bernstein
authors.forename: Matthias B
authors.initials: MB
authors.lastname: Schulze
authors.forename: JoAnn E
authors.initials: JE
authors.lastname: Manson
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.forename: Frank B
authors.initials: FB
authors.lastname: Hu
mesh_terms: D000328:Adult; D000368:Aged; D015331:Cohort Studies; D003924:Diabetes Mellitus, Type 2 / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control; D004032:Diet / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D005511:Food Handling; D006801:Humans; D015994:Incidence; D008297:Male; D008460:Meat / Q000009:adverse effects*; D008875:Middle Aged; D011446:Prospective Studies; D015203:Reproducibility of Results; D012306:Risk; D011795:Surveys and Questionnaires; D014481:United States / Q000453:epidemiology