title: Longitudinal changes in the dietary inflammatory index: an assessment of the inflammatory potential of diet over time in postmenopausal women.
abstract: The dietary inflammatory index (DII) measured at one time point is associated with risk of several chronic diseases, but disease risk may change with longitudinal changes in DII scores. Data are lacking regarding changes in DII scores over time; therefore, we assessed changes in the DII in the Women's Health Initiative (WHI).
  
  
  
  DII scores were calculated using data from repeated food frequency questionnaires in the WHI Observational Study (OS; n=76 671) at baseline and year 3, and the WHI Dietary Modification trial (DM; n=48482) at three time points. Lower DII scores represent more anti-inflammatory diets. We used generalized estimating equations to compare mean changes in DII over time, adjusting for multiple comparisons, and multivariable-adjusted linear regression analyses to determine predictors of DII change.
  
  
  
  In the OS, mean DII decreased modestly from -1.14 at baseline to -1.50 at year 3. In the DM, DII was -1.32 in year 1, -1.60 in year 3 and -1.48 in year 6 in the intervention arm and was -0.65 in year 1, -0.94 in year 3 and -0.96 in year 6 in the control arm. These changes were modified by body mass index, education and race/ethnicity. A prediction model explained 22% of the variance in the change in DII scores in the OS.
  
  
  
  In this prospective investigation of postmenopausal women, reported dietary inflammatory potential decreased modestly over time. Largest reductions were observed in normal-weight, highly educated women. Future research is warranted to examine whether reductions in DII are associated with decreased chronic disease risk.
authors.affiliation: Departments of Nutrition and Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA.|Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.|Cancer Prevention and Control Program, University of South Carolina, Columbia, SC, USA.
authors.forename: F K
authors.initials: FK
authors.lastname: Tabung
authors.affiliation: Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.|Cancer Prevention and Control Program, University of South Carolina, Columbia, SC, USA.|Center for Research in Nutrition and Health Disparities, University of South Carolina, Columbia, SC, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Steck
authors.affiliation: Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Division of Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Ma
authors.affiliation: Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.|Center for Research in Nutrition and Health Disparities, University of South Carolina, Columbia, SC, USA.
authors.forename: A D
authors.initials: AD
authors.lastname: Liese
authors.affiliation: Department of Preventive Medicine, University of Tennessee Health Science Center, Memphis, TN, USA.
authors.forename: F A
authors.initials: FA
authors.lastname: Tylavsky
authors.affiliation: Department of Epidemiology and Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA.
authors.forename: M Z
authors.initials: MZ
authors.lastname: Vitolins
authors.affiliation: Division of Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
authors.forename: J K
authors.initials: JK
authors.lastname: Ockene
authors.affiliation: Department of Epidemiology and Biostatistics, University of South Carolina, Columbia, SC, USA.|Cancer Prevention and Control Program, University of South Carolina, Columbia, SC, USA.
authors.forename: J R
authors.initials: JR
authors.lastname: Hebert
mesh_terms: D002908:Chronic Disease; D004032:Diet / Q000706:statistics & numerical data*; D004034:Diet Surveys / Q000379:methods; D004522:Educational Status; D005260:Female; D006305:Health Status Indicators; D006801:Humans; D056865:Ideal Body Weight; D007249:Inflammation / Q000150:complications / Q000175:diagnosis*; D008137:Longitudinal Studies; D008875:Middle Aged; D017698:Postmenopause; D011446:Prospective Studies; D018570:Risk Assessment / Q000379:methods*