Longitudinal associations between vegetarian dietary habits and site-specific cancers in the Adventist Health Study-2 North American cohort

Q: What was the main objective of this study?

To describe multivariable-adjusted associations between different types of vegetarian diets (vs nonvegetarians) and cancer risk at different bodily sites.

Q: How were participants and cancer outcomes determined?

The cohort included North American Seventh-day Adventists with 79,468 participants initially free of cancer; baseline diet came from a food frequency questionnaire, and incident cancers were identified by matching with state and Canadian provincial cancer registries.

Q: Which cancer outcomes showed significantly lower risk among vegetarians?

Vegetarians had significantly less frequent overall cancers and medium-frequency cancers, and specific reductions were reported for colorectal, stomach, and lymphoproliferative cancers.

Sep 23, 2026

Uploaded by Jasmine

Longitudinal analyses evaluated how different vegetarian dietary habits relate to cancer risk across multiple anatomical sites within the Adventist Health Study-2 North American cohort. The study included 79,468 participants free of cancer at baseline, using food frequency questionnaire data and incident cancer ascertainment via state and Canadian provincial cancer registries. Proportional hazard regression estimated hazard ratios with multiple imputation for missing data. Vegetarian diets, compared with nonvegetarians, were linked to lower overall cancer risk and reduced risk for medium-frequency cancers, with site-specific reductions for colorectal, stomach, and lymphoproliferative cancers.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages9

Reading Time23 min

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Abstract

Introduction

The American Journal of Clinical Nutrition 122 (2025) 535–543 journal homepage: [https://ajcn.nutrition.org/](https://ajcn.nutrition.org/) Original Research Article Longitudinal associations between vegetarian dietary habits and site-speciﬁc cancers in the Adventist Health Study-2 North American cohort Gary E Fraser 1, 2, 3, *, Fayth M Butler 1, 2, 4, David J Shavlik 5, Roy O Mathew 6, 7, Jisoo Oh 2, 5, Rawiwan Sirirat 1, 2, Dmitry Abramov 3, Lars E Sveen 1 1 Adventist Health Study, Research Affairs, Loma Linda University, Loma Linda, CA, United States; 2 Center for Nutrition, Healthy Lifestyles and Disease Prevention, School of Public Health, Loma Linda University, Loma Linda, CA, United States; 3 Division of Cardiology, Department of Medicine, Loma Linda University School of Medicine and Loma Linda University Health, Loma Linda, CA, United States; 4 Division of Biochemistry, Department of Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, United States; 5 School of Public Health, Loma Linda University, Loma Linda, CA, United States; 6 Division of Nephrology, Department of Medicine, Loma Linda VA Healthcare System, Loma Linda, CA, United States; 7 Division of Nephrology, Department of Medicine, Loma Linda University School of Medicine and Loma Linda University Health, Loma Linda, CA, United States | A B S T R A C T | | --- | | Background: Associations between vegetarian diets and risk of common cancers are somewhat understood, but such data on medium-frequency cancers are scarce and often imprecise.
Objectives: The objectives of this study was to describe multivariable-adjusted associations between different types of vegetarian diets (compared with nonvegetarians) and risk of cancers at different bodily sites.
Methods: The Adventist Health Study is a cohort of 95,863 North American Seventh-day Adventists established between 2002 and 2007 . These analyses used 79,468 participants initially free of cancer. Baseline dietary data were obtained using a food frequency questionnaire and incident cancers by matching with state and Canadian provincial cancer registries. Hazard ratios (HRs) were estimated using proportional hazard regression. Small amounts of missing data were ﬁlled using multiple imputations.
Results: Overall cancers, all vegetarians combined compared with nonvegetarians, had HR: 0.88; 95% conﬁdence interval (CI): 0.83,0.93; P < 0.001, and for medium frequency cancers, HR: 0.82; 95% CI: 0.76, 0.89; P < 0.001. Of speciﬁc cancers, colorectal (HR: 0.79; 95% CI: 0.66, 0.95; P ¼ 0.011), stomach (HR: 0.55; 95% CI: 0.32, 0.93; P ¼ 0.025), and lymphoproliferative (HR: 0.75; 95% CI: 0.60,0.93; P ¼ 0.010) cancers, were signiﬁcantly less frequent among vegetarians. A joint test that HR ¼ 1.0 for all vegetarian subtypes compared with nonvegetarians was rejected for cancers ofthe breast (P ¼ 0.012), lymphoma (P ¼ 0.031), all lymphoproliferative cancers (P ¼ 0.004), prostate cancer (P ¼ 0.030), colorectal cancers (P ¼ 0.023), medium frequency cancers (P < 0.001), and for all cancers combined (P < 0.001) .
Conclusions: These data indicate a lower risk in vegetarians for all cancers combined, as well as for medium-frequency cancers as a group. Speciﬁc cancers with evidence of lower risk are breast, colorectal, prostate, stomach, and lymphoproliferative subtypes. Risk at some other sites may also differ in vegetarians, but statistical power was limited.
Keywords: vegetarian subtypes, site-speciﬁc cancers, Seventh-day Adventists, North American subjects, Adventist Health Study-2 | Introduction A common characteristic of vegetarians, as compared with more typical Western diets, is a greater content of fruit, vegetables, nuts, and legumes [1,2], which contain phytochemicals thought to protect against cancer [3] . In addition, there is the absence of meats, some of which probably promote certain cancers. Vegetarians are, on average (mean values), less prone to overweight [4,5], wh

FAQs

What was the main objective of this study?

To describe multivariable-adjusted associations between different types of vegetarian diets (vs nonvegetarians) and cancer risk at different bodily sites.

How were participants and cancer outcomes determined?

The cohort included North American Seventh-day Adventists with 79,468 participants initially free of cancer; baseline diet came from a food frequency questionnaire, and incident cancers were identified by matching with state and Canadian provincial cancer registries.

Which cancer outcomes showed significantly lower risk among vegetarians?

Vegetarians had significantly less frequent overall cancers and medium-frequency cancers, and specific reductions were reported for colorectal, stomach, and lymphoproliferative cancers.

Sep 23, 2026

Uploaded by Jasmine