---
title: "Ultra-processed food intake not linked to colorectal cancer incidence in large NIH‑AARP cohort"
id: "plos-medicine-0-associations-of-food-processing-and-dietary-risk-factors-with-colorectal-cancer"
canonical_url: "https://medichelpline.com/clinical-feed/plos-medicine-0-associations-of-food-processing-and-dietary-risk-factors-with-colorectal-cancer"
content_type: "clinical_feed_article"
specialty: "Oncology"
source_name: "PLOS Medicine"
source_url: "https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251"
published_at: "2026-10-15T14:00:00.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Ultra-processed food intake not linked to colorectal cancer incidence in large NIH‑AARP cohort
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/plos-medicine-0-associations-of-food-processing-and-dietary-risk-factors-with-colorectal-cancer
- **Specialty:** [Oncology](https://medichelpline.com/clinical-feed/oncology.md)
- **Primary Source:** PLOS Medicine
- **Source URL:** [Original Journal Publication](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251)
- **Published At:** 2026-10-15T14:00:00.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- The NIH‑AARP Diet and Health Study followed 461,682 cancer‑free US adults aged 50–71 who completed a food frequency questionnaire at enrollment; investigators identified 10,075 colorectal adenocarcinoma cases during follow-up through 2018. - Median **ultra-processed food (UPF)** intake was 293 g/1000 kcal/day, equating to about 43% of daily energy intake in this cohort. - The primary analysis used multivariable Cox proportional hazards models adjusted for age, sex, race/ethnicity, education, physical activity, smoking, alcohol, and other lifestyle and health factors; the exposure was UPF in g/1000 kcal/day categorized into sex-specific quintiles. - Total UPF intake showed no association with **colorectal cancer** incidence: hazard ratio for 5th versus 1st quintile 0.97 (95% CI 0.91–1.03), p-trend = 0.55. - Investigators examined dietary components by processing source. **Whole grain**, fiber, dairy, and calcium intakes from UPF sources were inversely associated with CRC incidence. - Meat intake from UPF sources was positively associated with CRC incidence, consistent with established evidence linking processed meat to higher CRC risk. - The authors emphasized that UPF category mixes foods with opposing associations (some protective, some harmful), which may explain heterogeneous results across cohorts. - Main study limitations were its observational design, potential residual confounding, and exposure misclassification from self-reported dietary data; the source did not report biological equivalence of nutrients from UPF versus non-UPF sources. - Authors concluded that results support existing guidance to consume **whole grains**, **fiber**, **dairy**, and **calcium** and to avoid **processed meat** for CRC prevention, while noting caution in interpreting UPF as a single risk exposure.
## Clinical Analysis & Structured Key Points
[ Skip to main content ](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#main-content) Advertisement * [plos.org](https://plos.org/) * [Create account](https://community.plos.org/registration/new) * [Sign in](https://journals.plos.org/user/secure/login?page=%2Fplosmedicine%2Farticle%3Fid%3D10.1371%2Fjournal.pmed.1005251) * * About * Browse * Publish * [](https://journals.plos.org/plosmedicine/ "PLOS Medicine") * Search [advanced search](https://journals.plos.org/plosmedicine/search) * 0 [Save](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#savedHeader) [Total Mendeley and Citeulike bookmarks.](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#savedHeader) * 0 [Citation](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#citedHeader) [Paper's citation count computed by Dimensions.](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#citedHeader) * 155 [View](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#viewedHeader) [PLOS views and downloads.](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#viewedHeader) * 0 [Share](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#discussedHeader) [Sum of Facebook, Twitter, Reddit and Wikipedia activity.](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251#discussedHeader) Open Access Peer-reviewed Research Article # Associations of food processing and dietary risk factors with colorectal cancer incidence in the NIH-AARP Diet and Health Study: A cohort study * Leila Abar , Contributed equally to this work with: Leila Abar, Caitlin P. O’Connell Roles Data curation, Formal analysis, Writing – original draft, Writing – review & editing Affiliation Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America ⨯ * Caitlin P. O’Connell , Contributed equally to this work with: Leila Abar, Caitlin P. O’Connell Roles Data curation, Formal analysis, Visualization, Writing – original draft, Writing – review & editing Affiliation Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0003-1068-4584 ](https://orcid.org/0000-0003-1068-4584 "ORCID Registry") ⨯ * Hyokyoung G. Hong, Roles Methodology, Writing – review & editing Affiliation Biostatistics Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0002-4280-6243 ](https://orcid.org/0000-0002-4280-6243 "ORCID Registry") ⨯ * Kirsten A. Herrick, Roles Methodology, Writing – review & editing Affiliation Risk Factor Assessment Branch, Division of Cancer Control and Population Sciences, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0001-8646-599X ](https://orcid.org/0000-0001-8646-599X "ORCID Registry") ⨯ * Lisa Kahle, Roles Data curation, Resources, Writing – review & editing Affiliation Information Management Services (IMS), Inc., Calverton, Maryland, United States of America ⨯ * Jennifer L. Lerman, Roles Methodology, Writing – review & editing Affiliation Risk Factor Assessment Branch, Division of Cancer Control and Population Sciences, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0003-2705-8643 ](https://orcid.org/0000-0003-2705-8643 "ORCID Registry") ⨯ * Linda M. Liao, Roles Project administration, Resources, Writing – review & editing Affiliation Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0002-1923-5294 ](https://orcid.org/0000-0002-1923-5294 "ORCID Registry") ⨯ * Xuehong Zhang, Roles Conceptualization, Writing – review & editing Affiliation Yale School of Nursing, Yale University, New Haven, Connecticut, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0002-8260-8508 ](https://orcid.org/0000-0002-8260-8508 "ORCID Registry") ⨯ * Xinyuan Zhang, Roles Conceptualization, Writing – review & editing Affiliation Channing Division of Network Medicine, Brigham and Women’s Hospital and Harvard Medical School, Boston, Massachusetts, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0002-2974-8392 ](https://orcid.org/0000-0002-2974-8392 "ORCID Registry") ⨯ * Longgang Zhao, Roles Conceptualization, Writing – review & editing Affiliation Yale School of Nursing, Yale University, New Haven, Connecticut, United States of America [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0001-9254-1952 ](https://orcid.org/0000-0001-9254-1952 "ORCID Registry") ⨯ * Sémi Zouiouich, Roles Resources, Writing – review & editing Affiliation Nutrition and Metabolism Branch, International Agency for Research on Cancer, World Health Organization, Lyon, France [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0003-0263-3285 ](https://orcid.org/0000-0003-0263-3285 "ORCID Registry") ⨯ * Rashmi Sinha, Roles Conceptualization, Resources, Writing – review & editing Affiliation Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America ⨯ * Neha Khandpur, Roles Conceptualization, Data curation, Methodology, Writing – review & editing Affiliation Division of Human Nutrition and Health, Wageningen University, Wageningen, Netherlands ⨯ * Eurídice Martínez Steele, Roles Conceptualization, Data curation, Methodology, Writing – review & editing Affiliations Centre for Epidemiological Studies in Health and Nutrition (NUPENS), University of São Paulo, São Paulo, Brazil, Department of Nutrition, School of Public Health, University of São Paulo, São Paulo, Brazil [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0002-2907-3153 ](https://orcid.org/0000-0002-2907-3153 "ORCID Registry") ⨯ * Erikka Loftfield Roles Conceptualization, Data curation, Formal analysis, Investigation, Methodology, Supervision, Writing – original draft, Writing – review & editing * E-mail: erikka.loftfield@qimrb.edu.au Affiliations Metabolic Epidemiology Branch, Division of Cancer Epidemiology and Genetics, National Cancer Institute, National Institutes of Health, Rockville, Maryland, United States of America, Population Health Program, QIMR Berghofer Medical Research Institute, Brisbane, Australia [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0002-3573-8748 ](https://orcid.org/0000-0002-3573-8748 "ORCID Registry") ⨯ # Associations of food processing and dietary risk factors with colorectal cancer incidence in the NIH-AARP Diet and Health Study: A cohort study * Leila Abar, * Caitlin P. O’Connell, * Hyokyoung G. Hong, * Kirsten A. Herrick, * Lisa Kahle, * Jennifer L. Lerman, * Linda M. Liao, * Xuehong Zhang, … * Xinyuan Zhang, * Longgang Zhao ![PLOS](https://journals.plos.org/resource/img/logo-plos-full-color.svg) x * Published: October 15, 2026 * * [Article](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251) * [Authors](https://journals.plos.org/plosmedicine/article/authors?id=10.1371/journal.pmed.1005251) * [Metrics](https://journals.plos.org/plosmedicine/article/metrics?id=10.1371/journal.pmed.1005251) * [Comments](https://journals.plos.org/plosmedicine/article/comments?id=10.1371/journal.pmed.1005251) * [Media Coverage](http://plos.altmetric.com/details/doi/10.1371/journal.pmed.1005251) * [Abstract](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#abstract0) * [Author summary](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#abstract1) * [Introduction](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#sec004) * [Methods](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#sec005) * [Results](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#sec010) * [Discussion](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#sec011) * [Supporting information](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#sec012) * [Acknowledgments](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#ack) * [References](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#references) * [Reader Comments](https://journals.plos.org/plosmedicine/article/comments?id=10.1371/journal.pmed.1005251) * [Figures](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251) ## 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]; _p_ _trend_ = 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. ## Author summary ### Why was this study done? * Prospective studies of ultra-processed food (UPF) intake and colorectal cancer (CRC) incidence have yielded mixed results. * UPF represent a heterogeneous array of foods—including some, such as whole grain and dairy products, that have been associated with lower CRC risk, and others, such as processed meat products, that have been associated with higher CRC risk. ### What did the researchers do and find? * We analyzed data from 461,682 participants who were cancer-free at baseline in the NIH-AARP Diet and Health Study, among whom 10,075 colorectal adenocarcinoma cases were diagnosed during follow-up. * We estimated associations between CRC incidence and total UPF intake, UPF subgroups, and key dietary factors (dairy, whole grain, and meat) from UPF and non-UPF sources. * Total UPF intake was not associated with CRC incidence. * Whole grain, fiber, dairy, and calcium intakes from UPF sources were associated with lower CRC incidence; meat intake from UPF sources was associated with higher CRC incidence. ### What do these findings mean? * Our findings support current evidence-based dietary guidance to consume whole grains, fiber, dairy, and calcium and to avoid processed meat for CRC prevention. * Our findings do not address whether dietary components from UPF and non-UPF sources are biologically equivalent and should be interpreted with caution given limitations of the observational design. ## Figures ![Fig 1](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.g001) ![Fig 2](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.g002) ![Table 1](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.t001) ![Table 2](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.t002) ![Table 3](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.t003) ![Fig 1](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.g001) ![Fig 2](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.g002) ![Table 1](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.t001) ![Table 2](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.t002) ![Table 3](https://journals.plos.org/plosmedicine/article/figure/image?size=inline&id=10.1371/journal.pmed.1005251.t003) **Citation:** Abar L, O’Connell CP, Hong HG, Herrick KA, Kahle L, Lerman JL, et al. (2026) Associations of food processing and dietary risk factors with colorectal cancer incidence in the NIH-AARP Diet and Health Study: A cohort study. PLoS Med 23(10): e1005251. https://doi.org/10.1371/journal.pmed.1005251 **Academic Editor:** Fumiaki Imamura, University of Cambridge, UNITED KINGDOM OF GREAT BRITAIN AND NORTHERN IRELAND **Received:** January 7, 2026; **Accepted:** August 28, 2026; **Published:** October 15, 2026 This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the [Creative Commons CC0](https://creativecommons.org/publicdomain/zero/1.0/) public domain dedication. **Data Availability:** Data are maintained by the National Cancer Institute, Division of Cancer Epidemiology and Genetics and are available upon approval of a proposal to the NIH-AARP Diet and Health Study Steering Committee through the submission website and execution of a data transfer agreement as required by NIH policy for the Transfer of Materials from the NIH Intramural Laboratories. The code used in the analysis is available from Github . . **Funding:** The research leading to these results received funding from the Intramural Research Program of the National Cancer Institute, National Institutes of Health (EL): . Authors LA, CPO, HGH, LML, SZ, RS, and EL are/were employees of the funder, the Intramural Research Program of the National Cancer Institute. The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. **Competing interests:** The authors have declared that no competing interests exist. **Abbreviations:** BMI, body mass index; CI, confidence intervals; CRC, colorectal cancer; CSFII, Continuing Survey of Food Intake of Individuals; EPIC, European Prospective Investigation into Cancer; FFQ, food frequency questionnaire; FNDDS, Food and Nutrient Database for Dietary Studies; FP, Food Patterns; FPID, Food Patterns Ingredient Database; HEI, Healthy Eating Index; HR, hazard ratios; IMS, Information Management Services; IQR, interquartile range; NIH, National Institutes of Health; SR, standard reference; UKB, UK Biobank; UPF, ultra-processed food ## Introduction Colorectal cancer (CRC) is the third most commonly diagnosed cancer in the United States (US) [[1](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref001)], and dietary intake [[2](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref002)–[4](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref004)] has been linked to CRC development. The 2018 World Cancer Research Fund Report concluded that higher processed meat, red meat, and alcohol intake are associated with higher CRC risk, while higher whole grain, fiber, dairy, and calcium intake are associated with lower CRC risk [[5](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref005)]. Consumption of ultra-processed foods (UPF; Nova group 4) has been associated with higher CRC incidence in some but not all prospective cohort studies [[6](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref006)–[10](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref010)], and it remains unclear how current evidence-based dietary guidance for CRC prevention intersects with research on food processing. Evidence- based dietary guidelines also recommend limiting intake of added sugar, sodium, and saturated fat [[11](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref011)–[13](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref013)] and prioritizing whole foods to improve health [[14](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref014),[15](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref015)]. While most UPF are energy dense and nutrient poor [[11](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref011)–[13](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref013)], some are not (e.g., whole wheat bread). A 2023 study demonstrated that it is possible, though perhaps not practical [[16](https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1005251#pmed.1005251.ref016)], for dietary patterns high in UPF to receive high diet qua
## Related Clinical Research

- [Camupepimut (ELI-002 7P) in KRAS-mutant PDAC: Phase 2 AMPLIFY-7P results](https://medichelpline.com/clinical-feed/nature-1-lymph-node-targeted-mkras-specific-amphiphile-vaccine-in-pancreatic-cancer-the.md)
- [Chromosomal instability drives continual flux in cancer genomes: rates, distribution, and ploidy l](https://medichelpline.com/clinical-feed/biorxiv-9-chromosomal-instability-drives-continual-flux-in-cancer-genomes.md)
- [Cardiorespiratory fitness and sex modify colorectal cancer–suppressive effects of post-exercise se](https://medichelpline.com/clinical-feed/biorxiv-7-cardiorespiratory-fitness-and-sex-impact-the-colorectal-cancer-suppressive.md)
- [MSI‑High Colorectal Cancer in an Adolescent: Integrated Surgical, Molecular, and Adjuvant Manageme](https://medichelpline.com/clinical-feed/pubmed-42892709.md) (DOI: 10.12659/AJCR.953248)
- [CXCL14+ fibroblasts drive IBD-associated fibrosis and cancer through collagen IV–SPP1+ macrophage](https://medichelpline.com/clinical-feed/british-journal-of-cancer-0-cxcl14-fibroblasts-promote-development-of-ibd-associated-fibrosis-and-cancer-by.md)

## Navigation
- [← Back to Oncology Feed](https://medichelpline.com/clinical-feed/oncology.md)
- [← All Clinical Specialties](https://medichelpline.com/clinical-feed.md)
## Medical & Regulatory Disclaimer

> [!CAUTION]
> MedicHelpline content is structured for research, educational, and professional discovery purposes. It does not constitute individual medical advice, clinical diagnosis, or treatment recommendations.
> Always verify dosing, contraindications, and regulatory alerts against official product labeling and primary regulatory sources before clinical decision-making.