Low-Carbohydrate and Plant-Based Dietary Effects on Vascular Health

Not Applicable

Completed

• Conditions: Hypertension; Heart Disease, Ischemic; Hyperlipidemias
• Interventions: Other: Whole-Food, Plant-Based Diet and Low-Carbohydrate Diet

• Registration Number: NCT05414851
• Lead Sponsor: University of Rochester

Brief Summary

This is a randomized trial with a crossover design to investigate the short-term effects of two different dietary patterns on markers of vascular health. A low-carbohydrate diet and a whole-food, plant-based diet will be used. In addition to more traditional markers (cholesterol, blood pressure, inflammation), endothelial progenitor cells and trimethylamine N-oxide will be assessed.

Detailed Description

This study is an investigation of the short-term effects of two different diets on both conventional as well as newer markers of vascular health among subjects over the age of 50 who have a cardiovascular risk factor. The low-carbohydrate diet will be consistent with low-carbohydrate diet maintenance plans, with "net" carbs kept under 50g per day. The whole-food, plant-based diet will exclude animal foods, oils, and solid fats. Meals will be provided, and subjects will consume each diet for 2 weeks, with a 4-6 week washout period between dietary phases. Subjects will be randomized 1:1 to start with either the plant-based diet or the low-carbohydrate diet. Its primary aim is to assess the short-term effect of a whole-food, plant-based diet and a low-carbohydrate diet on levels of endothelial progenitor cells and trimethylamine N-oxide among this population. Secondarily, we will assess more conventional measures of vascular risk, including cholesterol, weight, blood pressure, insulin resistance, and inflammatory marker, as well as fullness and changes in nutritional intake.

Study Timeline

• Study First Submitted: 2022-06-02
• Study First Submitted QC: 2022-06-07
• Study First Posted: 2022-06-10
• Study Start: 2022-12-20
• Primary Completion: 2024-04-23
• Study Completion: 2024-04-23
• Status Verified: 2024-07
• Last Update Submitted: 2024-07-15
• Last Update Posted: 2024-07-16

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 45

Inclusion Criteria

• Age >50
• Diagnosis of any of the following cardiovascular risk factors: hypertension (Diagnosis present in chart or use of antihypertensive medications); hyperlipidemia/dyslipidemia (non-HDL cholesterol ≥ 130 within the past year or current use of antihyperlipidemic medication); prediabetes (HbA1c ≥ 5.7% and < 6.5% in the past year); diabetes (HbA1c ≥ 6.5% in the past year); obesity (body mass index ≥ 30).
• Willing and able to comply with the protocol for the duration of the study, including food provision, scheduled meetings and testing visits.
• Able to speak and read English fluently because counseling and education is only available in English.

Exclusion Criteria

• Active malabsorption syndrome (celiac disease, history of gastric bypass within the past year, uncontrolled Crohn's disease, protein-losing enteropathy, etc...)
• Use of any of the following medications that require close monitoring and adjustment during major dietary change: insulin, sulfonylureas, or warfarin
• Chronic or acute kidney disease, with eGFR < 50 on two or more lab tests in the past 6 months
• Diagnosis of cirrhosis or liver failure
• Hyperkalemia (defined as potassium >5.4 on two or more lab tests in the past 6 months)
• Major surgery in the past 3 months
• Myocardial infarction in the past 6 months
• Current, active eating disorder as determined by chart review, investigator assessment, or subject history
• Food allergies or intolerances that would interfere with eating study food or require special accommodation as determined by subject history, investigator assessment, or chart review
• Consuming a current diet described by the subject as vegetarian, vegan, very low-carbohydrate, or ketogenic
• Illicit drug use (not including marijuana)
• High risk alcohol use, based on subject history (defined as greater than 7 drinks/week for women and greater than 14 drinks/week for men)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Whole-Food, Plant-Based Start	Whole-Food, Plant-Based Diet and Low-Carbohydrate Diet	This group starts with the whole-food, plant-based diet, then gets the low-carbohydrate diet after the washout period.
Low-Carbohydrate Start	Whole-Food, Plant-Based Diet and Low-Carbohydrate Diet	This group starts with the low-carbohydrate diet, then gets the whole-food, plant-based diet after the washout period.

Primary Outcome Measures

Name	Time	Method
trimethylamine N-oxide	2 weeks
HDL function	2 weeks
Endothelial Progenitor Cells	2 weeks

Secondary Outcome Measures

Name	Time	Method
Insulin resistance	2 weeks	HOMA-IR
Insulin	2 weeks
Blood Glucose	2 weeks
Change in nutritional intake	2 weeks	assessed by 3 day food records at baseline and in second week of dietary phase
Resting Heart Rate	2 weeks
Weight	2 weeks
Cholesterol Panel	2 weeks	Total, LDL, HDL, non-HDL cholesterol, and triglycerides
Blood Pressure	2 Weeks
Inflammatory Markers	2 weeks	hsCRP, TNF-a, IL-6
Satiety Assessment	2 weeks	Adapted SLIM (satiety labeled intensity magnitude)
Food "liking"	2 weeks	5 food liking factor scales adapted from 5-Factor Satiety Questionnaires

Trial Locations

Locations (1)

UR Medicine Nutrition in Medicine Research Center; 🇺🇸 Webster, New York, United States