Twins Nutrition Study (TwiNS): Vegan vs. Omnivore

NCT05297825 | Completed DMC

• 1 other identifier: 63995
• Study Type: interventional
• Target: 44
• Locations: 1 country
• Sites: 1

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.

Conditions

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

Keywords

Lipids; Glucose; Body weight; Microbiome; Inflammation; Immune function

Outcome Measures

Primary Outcomes (1)

• Difference in LDL cholesterol

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

  Baseline and 8 weeks

Secondary Outcomes (3)

• Difference in triglycerides

  Baseline and 8 weeks

• Change in inflammatory markers

  Baseline and 8 weeks

• Change in alpha diversity

  Baseline and 8 weeks

Study Arms (2)

Vegan

EXPERIMENTAL

Participants will be asked to consume a healthy vegan diet.

Behavioral: Vegan diet

Omnivore

EXPERIMENTAL

Participants will be asked to consume a healthy omnivore diet.

Behavioral: Omnivore diet

Interventions

Vegan diet BEHAVIORAL

Healthy vegan diet.

Vegan

Omnivore diet BEHAVIORAL

Healthy omnivore diet.

Omnivore

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Age 18+
• /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

You may not qualify if:

• 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.

Sponsors & Collaborators

• Stanford University: lead

Study Sites (1)

Stanford University

Stanford, California, 94305, United States

Location

Related Publications (3)

• 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.

  PMID: 38032644 BACKGROUND

• Zeitlin AB, Ward CP, Minerva Cooper AO, Landry MJ, Krenek AM, Durand LR, Cunanan KM, Robinson JL, Dant CC, Gardner CD. Diet Quality and Comparison of Plant-Based Versus Omnivore Diets in Identical Twins: A Secondary Analysis of the Twins Nutrition Study (TwiNS). Curr Dev Nutr. 2025 Sep 4;9(10):107549. doi: 10.1016/j.cdnut.2025.107549. eCollection 2025 Oct.

  PMID: 41081008 DERIVED

• Dwaraka VB, Aronica L, Carreras-Gallo N, Robinson JL, Hennings T, Carter MM, Corley MJ, Lin A, Turner L, Smith R, Mendez TL, Went H, Ebel ER, Sonnenburg ED, Sonnenburg JL, Gardner CD. Unveiling the epigenetic impact of vegan vs. omnivorous diets on aging: insights from the Twins Nutrition Study (TwiNS). BMC Med. 2024 Jul 29;22(1):301. doi: 10.1186/s12916-024-03513-w.

  PMID: 39069614 DERIVED

Related Links

• Study description

MeSH Terms

Conditions

Glucose Intolerance; Body Weight Changes; Inflammation; Body Weight

Interventions

Diet, Vegan

Condition Hierarchy (Ancestors)

Hyperglycemia; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Pathologic Processes

Intervention Hierarchy (Ancestors)

Diet, Vegetarian; Diet, Plant-Based; Diet Therapy; Nutrition Therapy; Therapeutics; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Christopher D Garnder, PhD

  Stanford University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: March 17, 2022
• First Posted: March 28, 2022
• Study Start: March 17, 2022
• Primary Completion: July 20, 2022
• Study Completion: July 20, 2022
• Last Updated: January 12, 2024

Record last verified: 2023-12

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)