An observational study in Dementia, Depression and Cardiovascular Diseases, sponsored by Dalin Tzu Chi General Hospital. Completed at 1 site in Taiwan. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-09-12.
Sponsored by Dalin Tzu Chi General Hospital · Observational
To investigate the prospective association between a vegetarian diet and chronic degenerative diseases in two cohorts of Taiwanese Buddhists
The Tzu Chi Vegetarian Study (TCVS) recruited 12062 community volunteers of the Buddhists Tzu Chi Foundation throughout Taiwan in the year 2005. All participants completed a self-administered questionnaire on basic information, medical history, lifestyle, and diet.
The Tzu Chi Health Study (TCHS) recruited 6002 participants who came to the Buddhist Tzu Chi Dalin General Hospital for health examination. All participants were interviewed on basic information, medical history, lifestyle, and diet. Biochemical and anthropometric data was collected through a health examination:
Biochemical variables: CBC, fasting glucose, lipid profile (TCH, LDL, HDL, TG), BUN, Cr, ALT, AST, and UA. In addition, homocysteine, serum vitamin B12, folate, and C-reactive protein (CRP) are available for 1500 subjects.
Blood: Extra blood samples have been obtained and stored for 3500 subjects and will be available for future investigation.
Anthropometric variables: body weight, height, waist circumference, % body fat (with BIA), blood pressure, pulse wave velocity, bone mineral density through DXA (at spine for female and hip for male), lung function test (spirometric), abdominal sonography, colonoscopy, esophageal-gastro-duodenal-scopy, chest X-ray, KUB.
Follow-up: Individual baseline data were linked to the National Health Insurance Database and the National Death Registry to ascertain disease outcomes at the Health and Welfare Data Science Center.
2,372 studies on the registry are indexed under Dementia; 574 are open to participants now.
This study's enrollment of 18,064 is above the median of 256 across 553 observational studies indexed under Dementia.
Browse Dementia studies →Dalin Tzu Chi General Hospital is the lead sponsor of 37 studies on the registry; 6 are open to participants now.
Counted across the registry records on this site, refreshed daily.
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.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
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
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
Vegetarian diet vs nonvegetarian diet
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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: 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.
Time frame: From enrollment to December 31st 2014.
Plan to share: No — 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.
This study is completed, as verified in Mar 2018. You cannot join it, but the record below documents what was studied.
Get an email when the registry record changes — status, dates, results — or when someone posts here.
Sign in to followQuestions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.
Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.
Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.
Dalin Tzu Chi General Hospital