Twins Nutrition Study (TwiNS): Vegan vs. Omnivore (TwiNS)

• ClinicalTrials.gov Identifier: NCT05297825
• Recruitment Status: Completed
• First Posted: March 28, 2022
• Last Update Posted: January 12, 2024
• Sponsor: Stanford University
• Information provided by (Responsible Party): Christopher Gardner, Stanford University

Tracking Information

• First Submitted Date: March 17, 2022
• First Posted Date: March 28, 2022
• Last Update Posted Date: January 12, 2024
• Actual Study Start Date: March 17, 2022
• Actual Primary Completion Date: July 20, 2022 (Final data collection date for primary outcome measure)

Current Primary Outcome Measures (submitted: March 17, 2022)

Difference in LDL cholesterol [ Time Frame: Baseline and 8 weeks ]

Difference in the 8-week change-from-baseline in LDL cholesterol between the vegan vs. omnivore diet groups

• Original Primary Outcome Measures: Same as current

Current Secondary Outcome Measures (submitted: March 17, 2022)

• Difference in triglycerides [ Time Frame: Baseline and 8 weeks ]
  Difference in the 8-week change-from-baseline in triglycerides between the vegan vs. omnivore diet groups
• Change in inflammatory markers [ Time Frame: Baseline and 8 weeks ]
  Difference in the 8-week change-from-baseline in inflammatory markers detected in blood samples between the vegan vs. omnivore diet groups.
• Change in alpha diversity [ Time Frame: Baseline and 8 weeks ]
  Change from baseline in alpha diversity at 8 weeks in the vegan and omnivore diet groups. We will be using the number of observed sequence variants ("species") determined by standard 16S rRNA amplicon sequencing (V3-V5 region followed by DADA2 to define error-corrected sequence variants) as our primary metric of alpha diversity. We will also determine whether there is a change in observed sequence variants between the two groups. Higher alpha diversity is better. The units are the number of sequence variants.

• Original Secondary Outcome Measures: Same as current
• Current Other Pre-specified Outcome Measures: Not Provided
• Original Other Pre-specified Outcome Measures: Not Provided

Descriptive Information

• Brief Title: Twins Nutrition Study (TwiNS): Vegan vs. Omnivore
• Official Title: Twins Nutrition Study (TwiNS): Vegan vs. Omnivore
• Brief Summary: This study is designed to investigate the health impact of a vegan diet compared to a usual, omnivorous diet. The investigators plan to study these diets in twins, where one twin follows a vegan diet and the other twin follows an omnivorous diet, thus the investigators control for genetic differences that might impact the effect of the diet.
• Detailed Description: During this study, the investigators will evaluate the nutrient intake in both the vegan and the omnivorous diet. The investigators will also measure physiologic markers of health such as lipid levels, HbA1C, heart rate, and weight, and they will also look at the effect of the diets on the microbiota. In addition to measuring the effect of the diet, the investigators will monitor adherence to the diet, and survey participants on the ease/difficulty in following a vegan diet as well as their energy levels and sense of wellbeing. Thus, this study will help us better understand the health impact and feasibility of following a vegan diet. These results will be of much interest to the general public and the health care professionals.
• Study Type: Interventional
• Study Phase: Not Applicable
• Study Design: Allocation: Randomized; Intervention Model: Parallel Assignment; Masking: None (Open Label); Primary Purpose: Prevention

Condition

• Lipid Metabolism
• Glucose Intolerance
• Weight Change, Body
• Microbiome
• Inflammation
• Immune Function

Intervention

• Behavioral: Vegan diet
  Healthy vegan diet.
• Behavioral: Omnivore diet
  Healthy omnivore diet.

Study Arms

• Experimental: Vegan
  Participants will be asked to consume a healthy vegan diet.
  Intervention: Behavioral: Vegan diet
• Experimental: Omnivore
  Participants will be asked to consume a healthy omnivore diet.
  Intervention: Behavioral: Omnivore diet

• Publications *: Landry MJ, Ward CP, Cunanan KM, Durand LR, Perelman D, Robinson JL, Hennings T, Koh L, Dant C, Zeitlin A, Ebel ER, Sonnenburg ED, Sonnenburg JL, Gardner CD. Cardiometabolic Effects of Omnivorous vs Vegan Diets in Identical Twins: A Randomized Clinical Trial. JAMA Netw Open. 2023 Nov 1;6(11):e2344457. doi: 10.1001/jamanetworkopen.2023.44457. Erratum In: JAMA Netw Open. 2023 Dec 1;6(12):e2350422.

Recruitment Information

• Recruitment Status: Completed
• Actual Enrollment (submitted: May 11, 2022): 44
• Original Estimated Enrollment (submitted: March 17, 2022): 48
• Actual Study Completion Date: July 20, 2022
• Actual Primary Completion Date: July 20, 2022 (Final data collection date for primary outcome measure)

Eligibility Criteria

Inclusion Criteria:

• Age 18+
• 1/2 of a pair of twins that will both be participating
• Willing to consume a plant-based diet (vegetables, fruit, whole grains, legumes, etc.)
• Willing to consume meat/eggs (beef, pork/sausage, chicken, eggs) >= 1 time a day
• Willing to consume dairy (milk, yogurt, cheese) >= 1 time a day

Exclusion Criteria:

• Weight < 110 lb
• BMI >= 40
• LDL-C > 190 mg/dL
• Systolic Blood Pressure > 160 mmHg OR Diastolic blood pressure > 90 mmHg
• Pregnant, lactating or planning to become pregnant during the course of the study.

• Use of any of the following drugs/supplements within the last 2 months:

  • systemic antibiotics, antifungals, antivirals or antiparasitics (intravenous, intramuscular, or oral);
  • corticosteroids (intravenous, intramuscular, oral, nasal or inhaled);
  • cytokines;
  • methotrexate or immunosuppressive cytotoxic agents.
• Chronic, clinically significant, or unstable (unresolved, requiring on-going changes to medical management or medication) pulmonary, cardiovascular, gastrointestinal, hepatic or renal functional abnormality, as determined by medical history, Type 1 diabetes, dialysis
• History of active cancer in the past 3 years except for squamous or basal cell carcinomas of the skin that have been medically managed by local excision
• Unstable dietary history as defined by major changes in diet during the previous month, where the subject has eliminated or significantly increased a major food group in the diet.
• Recent history of chronic excessive alcohol consumption defined as more than five 1.5-ounce servings of 80 proof distilled spirits, five 12-ounce servings of beer or five 5-ounce servings of wine per day; or > 14 drinks/week.
• Any confirmed or suspected condition/state of immunosuppression or immunodeficiency (primary or acquired) including HIV infection, multiple sclerosis and Graves' disease.
• Surgery of the GI tract, with the exception of cholecystectomy and appendectomy, in the past five years. Any major bowel resection at any time.
• Regular/frequent use of smoking or chewing tobacco, e-cigarettes, cigars or other nicotine-containing products
• Regular use of prescription opiate pain medication

Sex/Gender

• Sexes Eligible for Study: All

• Ages: 18 Years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Contacts: Contact information is only displayed when the study is recruiting subjects
• Listed Location Countries: United States

Administrative Information

• NCT Number: NCT05297825
• Other Study ID Numbers: 63995
• Has Data Monitoring Committee: Yes

U.S. FDA-regulated Product

• Studies a U.S. FDA-regulated Drug Product: No
• Studies a U.S. FDA-regulated Device Product: No

IPD Sharing Statement

• Plan to Share IPD: No

• Current Responsible Party: Christopher Gardner, Stanford University
• Original Responsible Party: Christopher Gardner, Stanford University, Rehnborg Farquhar Professor of Medicine
• Current Study Sponsor: Stanford University
• Original Study Sponsor: Same as current
• Collaborators: Not Provided

Investigators

• Principal Investigator: Christopher D Garnder, PhD; Stanford University

• PRS Account: Stanford University
• Verification Date: December 2023