Associations of food processing and dietary risk factors with colorectal cancer incidence in the NIH-AARP Diet and Health Study: A cohort study
11 affiliations
- 1Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America
- 2Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America
- 3Risk Factor Assessment Branch, Division of Cancer Control and Population Sciences, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America
- 4Information Management Services (IMS), Inc., Calverton, Maryland, United States of America
- 5Yale School of Nursing, Yale University, New Haven, Connecticut, United States of America
- 6Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
- 7Nutrition and Metabolism Branch, International Agency for Research on Cancer, World Health Organization, Lyon, France
- 8Division of Human Nutrition and Health, Wageningen University, Wageningen, Netherlands
- 9Centre for Epidemiological Studies in Health and Nutrition (NUPENS), University of São Paulo, São Paulo, Brazil
- 10Department of Nutrition, School of Public Health, University of São Paulo, São Paulo, Brazil
- 11Population Health Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia
Abstract
Background: Ultra-processed foods (UPF) account for >50% of energy intake by US adults. UPF intake can include dietary components linked to lower colorectal cancer (CRC) risk, such as whole grain and dairy products, and others linked to higher CRC risk, such as processed meats, potentially explaining the heterogeneity of evidence for an association between UPF and CRC risk. Our goal was to estimate the associations of UPF and established CRC-related dietary factors, by UPF and non-UPF source, with CRC incidence in a large cohort study. Methods and findings: US adults, aged 50–71, who enrolled in the NIH-AARP Diet and Health Study in 1995–96, self-reported dietary intake using a food frequency questionnaire (FFQ). Median UPF intake was 293 g/1000 kcal/day or 43% of daily energy intake. We assigned disaggregated FFQ items to Nova classification and categorized UPF intake (g/1000 kcal/day) into sex-specific quintiles. Participants who were cancer-free at baseline (N = 461,682) were followed for cancer incidence through 2018, and 10,075 colorectal adenocarcinoma cases were diagnosed. We used multivariable-adjusted Cox proportional hazards regression models, adjusted for demographic, lifestyle, and health-related factors, including age, sex, race/ethnicity, education, physical activity, smoking, and alcohol drinking, to estimate associations for UPF and related dietary components with CRC incidence. UPF intake was not associated with CRC incidence (hazard ratio 5th versus 1st quintile 0.97; 95% confidence interval [0.91–1.03]; ptrend = 0.55). Whole grain, fiber, dairy, and calcium intakes from UPF sources were inversely but meat intake from UPF sources was positively associated with CRC incidence. The main limitations of the study relate to its observational design and include potential residual confounding and exposure misclassification owing to systematic or random error in self-reported dietary data. Conclusions: Total UPF intake was not associated with incident CRC in this cohort of older, US adults. This may be explained, in part, by opposing associations of some UPF with CRC risk. Our findings support current dietary guidance to consume whole grains, fiber, dairy, and calcium and avoid processed meat for CRC prevention. Why was this study done?: What did the researchers do and find?: What do these findings mean?: In this study, Leila Abar and colleagues examine ultra-processed food intake and colorectal cancer incidence in a large prospective cohort, finding no overall association and suggesting that the nutritional composition of these foods may be more relevant than their level of processing alone.
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BibTeX
@article{abar2026associations,
title = {{Associations of food processing and dietary risk factors with colorectal cancer incidence in the NIH-AARP Diet and Health Study: A cohort study}},
author = {Leila Abar and Caitlin P. O’Connell and Hyokyoung G. Hong and Kirsten A. Herrick and Lisa Kahle and Jennifer L. Lerman and Linda M. Liao and Xuehong Zhang and Xinyuan Zhang and Longgang Zhao and Sémi Zouiouich and Rashmi Sinha and Neha Khandpur and Eurídice Martínez Steele and Erikka Loftfield},
journal = {PLOS Medicine},
year = {2026},
month = oct,
doi = {10.1371/journal.pmed.1005251},
url = {https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Associations of food processing and dietary risk factors with colorectal cancer incidence in the NIH-AARP Diet and Health Study: A cohort study
AU - Leila Abar
AU - Caitlin P. O’Connell
AU - Hyokyoung G. Hong
AU - Kirsten A. Herrick
AU - Lisa Kahle
AU - Jennifer L. Lerman
AU - Linda M. Liao
AU - Xuehong Zhang
AU - Xinyuan Zhang
AU - Longgang Zhao
AU - Sémi Zouiouich
AU - Rashmi Sinha
AU - Neha Khandpur
AU - Eurídice Martínez Steele
AU - Erikka Loftfield
PY - 2026
DA - 2026/10/01
JO - PLOS Medicine
DO - 10.1371/journal.pmed.1005251
UR - https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251
AB - Background: Ultra-processed foods (UPF) account for >50% of energy intake by US adults. UPF intake can include dietary components linked to lower colorectal cancer (CRC) risk, such as whole grain and dairy products, and others linked to higher CRC risk, such as processed meats, potentially explaining the heterogeneity of evidence for an association between UPF and CRC risk. Our goal was to estimate the associations of UPF and established CRC-related dietary factors, by UPF and non-UPF source, with CRC incidence in a large cohort study. Methods and findings: US adults, aged 50–71, who enrolled in the NIH-AARP Diet and Health Study in 1995–96, self-reported dietary intake using a food frequency questionnaire (FFQ). Median UPF intake was 293 g/1000 kcal/day or 43% of daily energy intake. We assigned disaggregated FFQ items to Nova classification and categorized UPF intake (g/1000 kcal/day) into sex-specific quintiles. Participants who were cancer-free at baseline (N = 461,682) were followed for cancer incidence through 2018, and 10,075 colorectal adenocarcinoma cases were diagnosed. We used multivariable-adjusted Cox proportional hazards regression models, adjusted for demographic, lifestyle, and health-related factors, including age, sex, race/ethnicity, education, physical activity, smoking, and alcohol drinking, to estimate associations for UPF and related dietary components with CRC incidence. UPF intake was not associated with CRC incidence (hazard ratio 5th versus 1st quintile 0.97; 95% confidence interval [0.91–1.03]; ptrend = 0.55). Whole grain, fiber, dairy, and calcium intakes from UPF sources were inversely but meat intake from UPF sources was positively associated with CRC incidence. The main limitations of the study relate to its observational design and include potential residual confounding and exposure misclassification owing to systematic or random error in self-reported dietary data. Conclusions: Total UPF intake was not associated with incident CRC in this cohort of older, US adults. This may be explained, in part, by opposing associations of some UPF with CRC risk. Our findings support current dietary guidance to consume whole grains, fiber, dairy, and calcium and avoid processed meat for CRC prevention. Why was this study done?: What did the researchers do and find?: What do these findings mean?: In this study, Leila Abar and colleagues examine ultra-processed food intake and colorectal cancer incidence in a large prospective cohort, finding no overall association and suggesting that the nutritional composition of these foods may be more relevant than their level of processing alone.
SN - 1549-1676
SN - 1549-1277
ER -