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

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.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases; Microbiome; Immune Function
• Intervention / Treatment: Behavioral: Meat products; Behavioral: Plant Alternative products

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 Type: Interventional
• Enrollment (Actual): 38
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • California
    • Stanford, California, United States, 94305
      • Stanford University

Participation Criteria

Eligibility Criteria

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

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / 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.)

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Trimethylamine N-oxide (TMAO).	Change from baseline in TMAO at 8 weeks.	Baseline and 8 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Insulin-like Growth Factor-1 (IGF-1)	Change from baseline in IGF-1 at 8 weeks.	Baseline and 8 weeks
Microbiota composition	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.	Baseline and 8 weeks
Microbiota function	Change from baseline in composite of short-chain fatty acids (SCFA) concentration (ug/g stool: acetate + propionate + butyrate) at 8 weeks of each phase.	Baseline and 8 weeks
Total Cholesterol	Change from baseline in total cholesterol at 8 weeks of each phase.	Baseline and 8 weeks
LDL Cholesterol	Change from baseline in LDL cholesterol at 8 weeks of each phase.	Baseline and 8 weeks
HDL Cholesterol	Change from baseline in HDL cholesterol at 8 weeks of each phase.	Baseline and 8 weeks
Triglycerides	Change from baseline in triglycerides at 8 weeks of each phase.	Baseline and 8 weeks
Fasting glucose	Change from baseline in fasting glucose at 8 weeks of each phase.	Baseline and 8 weeks
Fasting insulin	Change from baseline in fasting insulin at 8 weeks of each phase.	Baseline and 8 weeks
Weight	Change from baseline in weight at 8 weeks of each phase.	Baseline and 8 weeks
Waist circumference	Change from baseline in weight at 8 weeks of each phase.	Baseline and 8 weeks
Blood pressure	Change from baseline in blood pressure at 8 weeks of each phase.	Baseline and 8 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Satisfaction with Plant Alternative products	Average satisfaction level with meals at 8 weeks of each phase (Meat phase compared to Plant Alternative phase) using a Likert scale.	Baseline and 8 weeks
Amount of Plant Alternative product consumption.	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.	Baseline and 8 weeks
Gastrointestinal symptoms	Change from baseline in gastrointestinal symptoms, as assessed by the Gastrointestinal Symptoms Study Questionnaire at 8 weeks of each phase.	Baseline and 8 weeks
Perceived stress	Change from baseline in perceived stress, as assessed by the PSS-10 questionnaire at 8 weeks of each phase.	Baseline and 8 weeks
Perceived cognitive function	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.	Baseline and 8 weeks
Perceived fatigue	Change from baseline in perceived fatigue, as assessed by the PROMIS SF v1.0 - Fatigue-4a questionnaire at 8 weeks of each phase.	Baseline and 8 weeks
Perceived overall health	Change from baseline in perceived overall health, as assessed by the PROMIS Scale v1.2-Global Health questionnaire at 8 weeks of each phase.	Baseline and 8 weeks
Perceived well-being	Change from baseline in perceived well-being, as assessed by the WHO Well-Being Index questionnaire at 8 weeks of each phase.	Baseline and 8 weeks

Collaborators and Investigators

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

Publications and helpful links

General 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.

Helpful Links

• Study description and results summary

Study record dates

Study Major Dates

• Study Start (Actual): January 17, 2019
• Primary Completion (Actual): December 5, 2019
• Study Completion (Actual): December 5, 2019

Study Registration Dates

• First Submitted: October 23, 2018
• First Submitted That Met QC Criteria: October 23, 2018
• First Posted (Actual): October 25, 2018

Study Record Updates

• Last Update Posted (Estimate): February 21, 2023
• Last Update Submitted That Met QC Criteria: February 18, 2023
• Last Verified: February 1, 2023

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: 48285

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No