Association between dietary inflammatory potential and breast cancer incidence and death: results from the Women's Health Initiative.
Diet modulates inflammation and inflammatory markers have been associated with cancer outcomes. In the Women's Health Initiative, we investigated associations between a dietary inflammatory index (DII) and invasive breast cancer incidence and death.



The DII was calculated from a baseline food frequency questionnaire in 122 788 postmenopausal women, enrolled from 1993 to 1998 with no prior cancer, and followed until 29 August 2014. With median follow-up of 16.02 years, there were 7495 breast cancer cases and 667 breast cancer deaths. We used Cox regression to estimate multivariable-adjusted hazards ratios (HRs) and 95% confidence intervals (95% CIs) by DII quintiles (Q) for incidence of overall breast cancer, breast cancer subtypes, and deaths from breast cancer. The lowest quintile (representing the most anti-inflammatory diet) was the reference.



The DII was not associated with incidence of overall breast cancer (HRQ5vsQ1, 0.99; 95% CI, 0.91-1.07; Ptrend=0.83 for overall breast cancer). In a full cohort analysis, a higher risk of death from breast cancer was associated with consumption of more pro-inflammatory diets at baseline, after controlling for multiple potential confounders (HRQ5vsQ1, 1.33; 95% CI, 1.01-1.76; Ptrend=0.03).



Future studies are needed to examine the inflammatory potential of post-diagnosis diet given the suggestion from the current study that dietary inflammatory potential before diagnosis is related to breast cancer death.
Departments of Nutrition and Epidemiology, Harvard T. H. Chan School of Public Health, Boston, MA, USA.|Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.|Cancer Prevention and Control Program, University of South Carolina, Columbia, SC, USA.
Fred K
FK
Tabung
Department of Epidemiology and Biostatistics, Arnold School of Public Health, 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.
Susan E
SE
Steck
Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.|Center for Research in Nutrition and Health Disparities, University of South Carolina, Columbia, SC, USA.
Angela D
AD
Liese
Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.
Jiajia
J
Zhang
Division of Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
Yunsheng
Y
Ma
Kaiser Permanente Division of Research, Oakland, CA, USA.
Bette
B
Caan
Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center (LABioMed), Torrance, CA, USA.
Rowan T
RT
Chlebowski
Department of Epidemiology and Environmental Health, University at Buffalo, The State University of New York, Buffalo, NY, USA.
Jo L
JL
Freudenheim
Department of Preventive Medicine and the Robert H. Lurie Comprehensive Cancer Center, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
Lifang
L
Hou
Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA.
Yasmin
Y
Mossavar-Rahmani
Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.|Cancer Prevention and Control Program, University of South Carolina, Columbia, SC, USA.
Nitin
N
Shivappa
Department of Epidemiology & Prevention, Wake Forest School of Medicine, Winston-Salem, NC, USA.
Mara Z
MZ
Vitolins
Department of Epidemiology and Environmental Health, University at Buffalo, The State University of New York, Buffalo, NY, USA.
Jean
J
Wactawski-Wende
Division of Preventive and Behavioral Medicine, University of Massachusetts Medical School, Worcester, MA, USA.
Judith K
JK
Ockene
Department of Epidemiology and Biostatistics, Arnold School of Public Health, University of South Carolina, Columbia, SC, USA.|Cancer Prevention and Control Program, University of South Carolina, Columbia, SC, USA.
James R
JR
Hébert
D000368:Aged; D015415:Biomarkers; D001943:Breast Neoplasms / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality / Q000473:pathology / Q000517:prevention & control; D002097:C-Reactive Protein / Q000032:analysis; D004032:Diet / Q000009:adverse effects*; D005247:Feeding Behavior; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007249:Inflammation / Q000097:blood / Q000150:complications / Q000453:epidemiology* / Q000209:etiology; D007378:Interleukins / Q000097:blood; D008875:Middle Aged; D017698:Postmenopause; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D012959:Socioeconomic Factors; D011795:Surveys and Questionnaires; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis; D014481:United States / Q000453:epidemiology
D015415:Biomarkers; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein