Plant-based Diets and Risk of Cancer in the Adventist Health Study-2 (AHS-2)

January 28, 2026 updated by: Loma Linda University

Cancer Epidemiology in Seventh-day Adventists

The Adventist Health Study-2 is a long-term study, exploring the links between lifestyle, diet, and disease outcomes among Seventh-day Adventists. More than 96,000 church members from the U.S. and Canada are participating in the current study, AHS-2, conducted by researchers at the Loma Linda University School of Public Health.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Active, not recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Detailed Description

The Adventist Health Study-2 (AHS-2) is a large national cohort of 96,000 Seventh-day Adventists in the U.S. and Canada. The study is searching for associations between diet and risk of common and medium frequency cancers (breast, prostate, colorectal, lung, uterus, pancreas, melanoma of skin). This cohort is unusual in that about half are vegetarian, many eat soy at Asian levels, and many have very low or absent dairy intake while others eat normal amounts of dairy. Thus observations on these people, many of whom have contrasting dietary habits, may provide insights about diet and cancer, so supporting dietary changes that could be readily adopted by many.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
96000

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • California
      • Loma Linda, California, United States, 92350
        • Loma Linda University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

26 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

Yes

Sampling Method

Non-Probability Sample

Study Population

The sample includes Seventh-day Adventist church members living in the USA and Canada who are 30 years and older, and who are sufficiently fluent in English to complete the lengthy lifestyle questionnaire. The study population is about 65% female. Approximately 25% of the cohort are Black/African Americans . Other ethnic minorities (e.g. Asian, Hispanic) are at much lower percentages (3-4 %).

Description

Inclusion Criteria:

  • Member of a Seventh-day Adventist church >30 years of age Ability to read English Live in the US or Canada

Exclusion Criteria:

  • Less than 30 years of age
  • Church members who did not complete the baseline questionnaire.
  • Incarcerated or institutionalized people
  • Non-English speakers

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: Cohort
  • Time Perspectives: Prospective

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Seventh-day Adventists
This is a prospective cohort study of 96,000 members of the Seventh-day Adventists Church in the United States and Canada age 30 and older at the time of enrollment who are proficient in English language.

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Incident cases of breast cancer among subjects with documented dietary habits.
Time Frame: Linkage with state cancer registries occurs periodically for 9 years, with first linkage at year 04 of study enrolment.
Incident cases of breast cancer as found by linkage with state cancer registries will allow calculation of hazard ratios comparing extreme quintiles of dietary intakes. The focus is on meats, soy, and dairy intakes.
Linkage with state cancer registries occurs periodically for 9 years, with first linkage at year 04 of study enrolment.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incident cases of prostate cancer among subjects with documented dietary intakes.
Time Frame: Linkage with state cancer registries occurs periodically for 9 years, with first linkage at year 04 of study enrolment.
Incident cases of prostate cancer as found by linkage with state cancer registries will allow calculation of hazard ratios comparing extreme quintiles of dietary intakes. The focus is on meats, soy, and dairy intakes.
Linkage with state cancer registries occurs periodically for 9 years, with first linkage at year 04 of study enrolment.

Other Outcome Measures

Other Outcome Measures

For clinical trials, a planned measurement described in the protocol that is used to determine the effect of an intervention/treatment on participants. For observational studies, a measurement or observation that is used to describe patterns of diseases or traits, or associations with exposures, risk factors, or treatment. Types of outcome measures include primary outcome measure and secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Incident cases of colorectal cancer among subjects with documented dietary habits.
Time Frame: Linkage with state cancer registries occurs periodically for 9 years, with first linkage at year 04 of study enrolment.
Incident cases of colorectal cancer as found by linkage with state cancer registries will allow calculation of hazard ratios comparing extreme quintiles of dietary intakes. The focus is on meats, soy, and dairy intakes.
Linkage with state cancer registries occurs periodically for 9 years, with first linkage at year 04 of study enrolment.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Loma Linda University

Collaborators

Collaborators

An organization other than the sponsor that provides support for a clinical study. This support may include activities related to funding, design, implementation, data analysis, or reporting.
National Cancer Institute (NCI)
World Cancer Research Fund International
Ardmore Institute of Health

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Gary E Fraser, MD,PhD, Loma Linda University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
February 1, 2002

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2013

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 1, 2028

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 29, 2018

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
July 30, 2018

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
August 6, 2018

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 30, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 28, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 48134
  • U01CA152939 (U.S. NIH Grant/Contract)
  • R01CA094594 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

Researchers must write a proposal describing how the data will be used and submit it to the Adventist Health Study data sharing committee for approval.

IPD Sharing Time Frame

on-going

IPD Sharing Access Criteria

Data access will be given upon approval of proposal by the AHS-2 Review Committee.

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF
  • ANALYTIC_CODE

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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