NCT03470584

Brief Summary

To investigate the prospective association between a vegetarian diet and chronic degenerative diseases in two cohorts of Taiwanese Buddhists

Trial Health

87
On Track

Trial Health Score

Automated assessment based on enrollment pace, timeline, and geographic reach

Enrollment
18,064

participants targeted

Target at P75+ for all trials

Timeline
Completed

Started Mar 2005

Longer than P75 for all trials

Geographic Reach
1 country

1 active site

Status
completed

Health score is calculated from publicly available data and should be used for screening purposes only.

Trial Relationships

Click on a node to explore related trials.

Study Timeline

Key milestones and dates

Study Start

First participant enrolled

March 1, 2005

Completed
10 months until next milestone

Primary Completion

Last participant's last visit for primary outcome

December 30, 2005

Completed
9 years until next milestone

Study Completion

Last participant's last visit for all outcomes

December 31, 2014

Completed
3.2 years until next milestone

First Submitted

Initial submission to the registry

March 12, 2018

Completed
8 days until next milestone

First Posted

Study publicly available on registry

March 20, 2018

Completed
Last Updated

September 12, 2025

Status Verified

March 1, 2018

Enrollment Period

10 months

First QC Date

March 12, 2018

Last Update Submit

September 8, 2025

Conditions

DementiaDepressionCardiovascular DiseasesStrokeGoutCataractGallstoneUrinary Tract Infections

Keywords

Diet, vegetarianDementiaDepressionCardiovascular DiseasesStrokeGoutCataractGallstoneUrinary Tract Infections

Outcome Measures

Primary Outcomes (8)

  • Gout

    Incidence of gout are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of gout are identified using ICD-9 code: 274.

    From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014).

  • Stroke

    Incidence of stroke are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of stroke are identified using ICD-9 code: 430-438, where hemorrhagic stroke is defined by ICD9 430-432 and ischemic stroke is defined by ICD9 433-434.

    From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014).

  • Cataract

    Incidence of cataract are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of cataract are identified using ICD-9 code: 366.

    From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014).

  • Gallstone disease

    Incidence of gallstone disease are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of gallstone diseases are identified using ICD-9 code: 574.

    From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014).

  • Dementia and mild cognitive impairment

    Incidence of dementia are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of dementia and mild cognitive impairment are identified using ICD-9 code: 290.0, 290.1,290.4, 331.0, 331.1, 331.82, 331.83.

    From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014).

  • Depression

    Incidence of depression are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of depression and are identified using ICD-9 code: 296.2, 296.3, 300.4 and 311.

    From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014).

  • Urinary tract infections (UTI)

    Incidence of UTI are ascertained by linking individual participants' baseline data to the the National Health Insurance Database. Cases of UTI are identified using ICD-9 code: 599.0, 595, 590.

    From enrollment to time of disease occurrence, death of any cause, or end of study period (December 31st 2014).

  • Medical expenditures

    Actual medical expenditure associated with different dietary patterns are analyzed. Medical expenditures are obtained and computed from the National Health Insurance Database claim data for outpatient treatment, inpatient treatment, and dental treatment. This also includes costs associated with laboratory work and medication prescription.

    From enrollment to December 31st 2014.

Study Arms (2)

Tzu Chi Vegetarian Study

12062 Tzu Chi volunteers of the Buddhist Tzu Chi Foundation recruited throughout communities in Taiwan in the year 2005. All participants filled out a self-administered questionnaire on basic information, medical history, lifestyle, and diet. Diet exposure: 1/3 vegetarians, 2/3 nonvegetarians.

Other: Diet Exposure

Tzu Chi Health Study

6002 participants who came for health examination at the Dalin Tzu Chi Hospital between the years 2007 to 2009. 77% were Tzu Chi volunteers. All participants were interviewed on a structured questionnaire including basic information, medical history, lifestyle, and diet, and received a comprehensive health examination. Diet exposure: 1/3 vegetarians, 2/3 nonvegetarians.

Other: Diet Exposure

Interventions

Diet ExposureOTHER

Vegetarian diet vs nonvegetarian diet

Tzu Chi Health StudyTzu Chi Vegetarian Study

Eligibility Criteria

Age18 Years+
Sexall
Healthy VolunteersYes
Age GroupsAdult (18-64), Older Adult (65+)
Sampling MethodNon-Probability Sample
Study Population

Participants in the Tzu Chi Vegetarian Study were all certified volunteers of the Buddhist Tzu Chi Foundation. Participants of the Tzu Chi Health Study were the ones who came to the Dalin Tzu Chi Hospital for health examination and agree to join the cohort study (77% were certified Tzu Chi volunteers). About 1/3 of both cohorts were vegetarians at enrollment.

You may qualify if:

  • Participants who consent to be followed.

You may not qualify if:

  • Participants with inaccurate ID which make linkage to NHIRD impossible.
  • Participants already with study outcome (disease) prior to enrollment in the study.
  • Participants with missing covariates

Contact the study team to confirm eligibility.

Sponsors & Collaborators

Study Sites (1)

Dalin Tzu Chi Hospital

Chiayi City, Taiwan

Location

Related Publications (6)

  • Chiu THT, Liu CH, Chang CC, Lin MN, Lin CL. Vegetarian diet and risk of gout in two separate prospective cohort studies. Clin Nutr. 2020 Mar;39(3):837-844. doi: 10.1016/j.clnu.2019.03.016. Epub 2019 Mar 27.

    PMID: 30955983BACKGROUND

  • Chiu THT, Chang HR, Wang LY, Chang CC, Lin MN, Lin CL. Vegetarian diet and incidence of total, ischemic, and hemorrhagic stroke in 2 cohorts in Taiwan. Neurology. 2020 Mar 17;94(11):e1112-e1121. doi: 10.1212/WNL.0000000000009093. Epub 2020 Feb 26.

    PMID: 32102976BACKGROUND

  • Chiu THT, Chang CC, Lin CL, Lin MN. A Vegetarian Diet Is Associated with a Lower Risk of Cataract, Particularly Among Individuals with Overweight: A Prospective Study. J Acad Nutr Diet. 2021 Apr;121(4):669-677.e1. doi: 10.1016/j.jand.2020.11.003. Epub 2020 Dec 11.

    PMID: 33309591BACKGROUND

  • Chang CM, Chiu THT, Chang CC, Lin MN, Lin CL. Plant-Based Diet, Cholesterol, and Risk of Gallstone Disease: A Prospective Study. Nutrients. 2019 Feb 4;11(2):335. doi: 10.3390/nu11020335.

    PMID: 30720747BACKGROUND

  • Lin CL, Wang JH, Chang CC, Chiu THT, Lin MN. Vegetarian Diets and Medical Expenditure in Taiwan-A Matched Cohort Study. Nutrients. 2019 Nov 6;11(11):2688. doi: 10.3390/nu11112688.

    PMID: 31698872BACKGROUND

  • Chen YC, Chang CC, Chiu THT, Lin MN, Lin CL. The risk of urinary tract infection in vegetarians and non-vegetarians: a prospective study. Sci Rep. 2020 Jan 30;10(1):906. doi: 10.1038/s41598-020-58006-6.

    PMID: 32001729BACKGROUND

Biospecimen

Retention: SAMPLES WITHOUT DNA

Serum samples for 3500 participants from the Tzu Chi Health Study

MeSH Terms

Conditions

DementiaDepressionCardiovascular DiseasesStrokeGoutCataractGallstonesUrinary Tract Infections

Condition Hierarchy (Ancestors)

Brain DiseasesCentral Nervous System DiseasesNervous System DiseasesNeurocognitive DisordersMental DisordersBehavioral SymptomsBehaviorCerebrovascular DisordersVascular DiseasesArthritisJoint DiseasesMusculoskeletal DiseasesCrystal ArthropathiesRheumatic DiseasesPurine-Pyrimidine Metabolism, Inborn ErrorsMetabolism, Inborn ErrorsGenetic Diseases, InbornCongenital, Hereditary, and Neonatal Diseases and AbnormalitiesMetabolic DiseasesNutritional and Metabolic DiseasesLens DiseasesEye DiseasesCholelithiasisBiliary Tract DiseasesDigestive System DiseasesCholecystolithiasisGallbladder DiseasesCalculiPathological Conditions, AnatomicalPathological Conditions, Signs and SymptomsInfectionsUrologic DiseasesFemale Urogenital DiseasesFemale Urogenital Diseases and Pregnancy ComplicationsUrogenital DiseasesMale Urogenital Diseases

Study Officials

  • Chin-Lon Lin, MD

    Dalin Tzu Chi General Hospital

    STUDY CHAIR

Study Design

Study Type
observational
Observational Model
COHORT
Time Perspective
PROSPECTIVE
Sponsor Type
OTHER
Responsible Party
SPONSOR

Study Record Dates

First Submitted

March 12, 2018

First Posted

March 20, 2018

Study Start

March 1, 2005

Primary Completion

December 30, 2005

Study Completion

December 31, 2014

Last Updated

September 12, 2025

Record last verified: 2018-03

Data Sharing

IPD Sharing
Will not share

The disease outcome data from the National Health Insurance Database belongs to the Ministry of Health in Taiwan. Access to these data requires permission and formal application to the Health and Welfare Data Science Center, Ministry of Health in Taiwan. This is regulated by local law and regulation to protect individual personal information. Our research team does not have the right to release any data other than summarized results in the forms of peer-reviewed publications, for noncommercial purposes.

Locations

TW(1)