SWAP-MEAT: Study With Appetizing Plant Food - Meat Eating Alternatives Trial (SWAP-MEAT)

• ClinicalTrials.gov Identifier: NCT03718988
• Recruitment Status: Completed
• First Posted: October 25, 2018
• Last Update Posted: September 4, 2020
• Sponsor: Stanford University
• Information provided by (Responsible Party): Christopher Gardner, Stanford University

Study Description

Brief Summary:

This study aims to investigate the impact of replacing meat consumption with plant-based meat alternative consumption on cardiovascular health, the gut microbiome, and metabolic status.

Condition or disease	Intervention/treatment	Phase
Microbiome; Immune Function; Cardiovascular Diseases	Behavioral: Meat products; Behavioral: Plant Alternative products	Not Applicable

Detailed Description:

Plant-based meat alternatives that closely emulate animal protein provide a new opportunity to decrease meat consumption worldwide. Decreasing meat consumption and shifting to a plant-based diet has been linked to improvements in physical health, including decreased risk of cardiovascular disease, metabolic syndrome, and type 2 diabetes (Kahleova, Levin, & Barnard, 2017). However, the extent to which plant-based meat alternatives specifically can modulate biomarkers of physical health, particularly TMAO and IGF-1, and the gut microbiome remain relatively unexplored. It is also largely unknown to what extent consumers can feasibly and sustainably exchange meat products for plant-based meat alternatives for extended periods of time. Plant-based meat alternatives offer a promising way to support consumers' shift to a plant-based diet, and in turn, to potentially improve levels of TMAO and IGF-1 and decrease cardiovascular risk. Thus, the investigators hypothesize that consumer levels of TMAO and IGF-1 will be improved after 8 weeks of consuming plant-based meat alternative products, as compared to 8 weeks of consuming traditional meat products.

Study Design

• Study Type: Interventional (Clinical Trial)
• Actual Enrollment: 38 participants
• Allocation: Randomized
• Intervention Model: Crossover Assignment
• Intervention Model Description: SWAP-MEAT is a randomized, cross-over design among 30 adults randomly assigned to one of two diet sequences. Each diet sequence will consist of two phases: the Meat phase, which will consist of participants consuming their typical diet, and the Plant Alternative phase, which will consist of participants consuming plant-based meat alternatives instead of their typical meat products, for a predominantly vegetarian diet.
• Masking: Double (Investigator, Outcomes Assessor)
• Primary Purpose: Prevention
• Official Title: SWAP-MEAT: Study With Appetizing Plant Food - Meat Eating Alternatives Trial
• Actual Study Start Date: January 17, 2019
• Actual Primary Completion Date: December 5, 2019
• Actual Study Completion Date: December 5, 2019

Arms and Interventions

Arm	Intervention/treatment
Experimental: Meat Phase first; Participants will be asked to consume traditional meat products for 8 weeks, then switch to plant-based meat alternative products for another 8 weeks.	Behavioral: Meat products; Traditional meat products (beef burger patties, pork sausage, etc.); Behavioral: Plant Alternative products; Plant-based alternatives (The Beyond Burger, Beyond Sausage, etc.)
Experimental: Plant Alternative Phase first; Participants will be asked to consume plant-based meat alternative products for 8 weeks, then switch to traditional meat products for another 8 weeks.	Behavioral: Meat products; Traditional meat products (beef burger patties, pork sausage, etc.); Behavioral: Plant Alternative products; Plant-based alternatives (The Beyond Burger, Beyond Sausage, etc.)

Outcome Measures

Primary Outcome Measures :

1. Trimethylamine N-oxide (TMAO). [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in TMAO at 8 weeks.

Secondary Outcome Measures :

1. Insulin-like Growth Factor-1 (IGF-1) [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in IGF-1 at 8 weeks.
2. Microbiota composition [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in alpha diversity at 8 weeks of each phase. We will be using 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. Higher alpha diversity is better. The units are the # of sequence variants.
3. Microbiota function [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in composite of short-chain fatty acids (SCFA) concentration (ug/g stool: acetate + propionate + butyrate) at 8 weeks of each phase.
4. Total Cholesterol [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in total cholesterol at 8 weeks of each phase.
5. LDL Cholesterol [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in LDL cholesterol at 8 weeks of each phase.
6. HDL Cholesterol [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in HDL cholesterol at 8 weeks of each phase.
7. Triglycerides [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in triglycerides at 8 weeks of each phase.
8. Fasting glucose [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in fasting glucose at 8 weeks of each phase.
9. Fasting insulin [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in fasting insulin at 8 weeks of each phase.
10. Weight [ Time Frame: Baseline and 8 weeks ]
    Change from baseline in weight at 8 weeks of each phase.
11. Waist circumference [ Time Frame: Baseline and 8 weeks ]
    Change from baseline in weight at 8 weeks of each phase.
12. Blood pressure [ Time Frame: Baseline and 8 weeks ]
    Change from baseline in blood pressure at 8 weeks of each phase.

Other Outcome Measures:

1. Satisfaction with Plant Alternative products [ Time Frame: Baseline and 8 weeks ]
   Average satisfaction level with meals at 8 weeks of each phase (Meat phase compared to Plant Alternative phase) using a Likert scale.
2. Amount of Plant Alternative product consumption. [ Time Frame: Baseline and 8 weeks ]
   Average number of daily servings of traditional meat products in Meat phase compared to average number of daily servings of Plant Alternative products in Plant Alternative phase.
3. Gastrointestinal symptoms [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in gastrointestinal symptoms, as assessed by the Gastrointestinal Symptoms Study Questionnaire at 8 weeks of each phase.
4. Perceived stress [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in perceived stress, as assessed by the PSS-10 questionnaire at 8 weeks of each phase.
5. Perceived cognitive function [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in perceived cognitive function, as assessed by the PROMIS SF v2.0 - Cognitive Function Abilities 4a and PROMIS SF v2.0 - Cognitive Function 4a questionnaires at 8 weeks of each phase.
6. Perceived fatigue [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in perceived fatigue, as assessed by the PROMIS SF v1.0 - Fatigue-4a questionnaire at 8 weeks of each phase.
7. Perceived overall health [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in perceived overall health, as assessed by the PROMIS Scale v1.2-Global Health questionnaire at 8 weeks of each phase.
8. Perceived well-being [ Time Frame: Baseline and 8 weeks ]
   Change from baseline in perceived well-being, as assessed by the WHO Well-Being Index questionnaire at 8 weeks of each phase.

Eligibility Criteria

• Ages Eligible for Study: 18 Years and older (Adult, Older Adult)
• Sexes Eligible for Study: All
• Accepts Healthy Volunteers: Yes

Criteria

Inclusion Criteria:

• Age ≥18
• Meat consumption (beef, pork/sausage, chicken) on average ≥ once a day
• Willing to consume meat (beef, pork/sausage, chicken) ≥ 2 times a day

Exclusion Criteria:

• Weight < 110 lb
• BMI ≥ 40
• LDL-C >190 mg/dL
• Systolic blood pressure (SBP) > 160 mmHg OR Diastolic blood pressure (DBP) > 90 mmHg

• 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.
• Regular/frequent use of smoking or chewing tobacco, e-cigarettes, cigars or other nicotine-containing products.
• Regular use of prescription opiate pain medication

Contacts and Locations

Locations

United States, California

Stanford University

Stanford, California, United States, 94305

Sponsors and Collaborators

Stanford University

Investigators

• Principal Investigator: Christopher D. Gardner, PhD; Stanford University

  Study Documents (Full-Text)

Documents provided by Christopher Gardner, Stanford University:

Statistical Analysis Plan  [PDF] December 23, 2019

More Information

Publications:

Crimarco A, Springfield S, Petlura C, Streaty T, Cunanan K, Lee J, Fielding-Singh P, Carter MM, Topf MA, Wastyk HC, Sonnenburg ED, Sonnenburg JL, Gardner CD. A randomized crossover trial on the effect of plant-based compared with animal-based meat on trimethylamine-N-oxide and cardiovascular disease risk factors in generally healthy adults: Study With Appetizing Plantfood-Meat Eating Alternative Trial (SWAP-MEAT). Am J Clin Nutr. 2020 Nov 11;112(5):1188-1199. doi: 10.1093/ajcn/nqaa203.

• Responsible Party: Christopher Gardner, Professor of Medicine, Stanford University
• ClinicalTrials.gov Identifier: NCT03718988
• Other Study ID Numbers: 48285
• First Posted: October 25, 2018
• Last Update Posted: September 4, 2020
• Last Verified: September 2020

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

Additional relevant MeSH terms:

Cardiovascular Diseases