Low-Carbohydrate and Plant-Based Dietary Effects on Vascular Health
Study Details
Study Description
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.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
N/A |
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 Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Whole-Food, Plant-Based Start This group starts with the whole-food, plant-based diet, then gets the low-carbohydrate diet after the washout period. |
Other: Whole-Food, Plant-Based Diet and Low-Carbohydrate Diet
Subjects will consume 2 weeks of each diet, with a 4-6 week washout period in between. Meals and snacks are provided for convenience for each dietary pattern. As the each diet is ad libitum, subjects can add or include their own home-prepared foods as long as they meet dietary guidelines.
|
| Experimental: Low-Carbohydrate Start This group starts with the low-carbohydrate diet, then gets the whole-food, plant-based diet after the washout period. |
Other: Whole-Food, Plant-Based Diet and Low-Carbohydrate Diet
Subjects will consume 2 weeks of each diet, with a 4-6 week washout period in between. Meals and snacks are provided for convenience for each dietary pattern. As the each diet is ad libitum, subjects can add or include their own home-prepared foods as long as they meet dietary guidelines.
|
Outcome Measures
Primary Outcome Measures
- Endothelial Progenitor Cells [2 weeks]
- trimethylamine N-oxide [2 weeks]
Secondary Outcome Measures
- Cholesterol Panel [2 weeks]
Total, LDL, HDL, non-HDL cholesterol, and triglycerides
- Blood Pressure [2 Weeks]
- Resting Heart Rate [2 weeks]
- Weight [2 weeks]
- Insulin resistance [2 weeks]
HOMA-IR
- Insulin [2 weeks]
- Blood Glucose [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
- Change in nutritional intake [2 weeks]
assessed by 3 day food records at baseline and in second week of dietary phase
Eligibility Criteria
Criteria
Inclusion Criteria:
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Age >50
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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).
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Willing and able to comply with the protocol for the duration of the study, including food provision, scheduled meetings and testing visits.
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Able to speak and read English fluently because counseling and education is only available in English.
Exclusion Criteria:
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Active malabsorption syndrome (celiac disease, history of gastric bypass within the past year, uncontrolled Crohn's disease, protein-losing enteropathy, etc…)
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Use of any of the following medications that require close monitoring and adjustment during major dietary change: insulin, sulfonylureas, or warfarin
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Chronic or acute kidney disease, with eGFR < 50 on two or more lab tests in the past 6 months
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Diagnosis of cirrhosis or liver failure
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Hyperkalemia (defined as potassium >5.4 on two or more lab tests in the past 6 months)
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Major surgery in the past 3 months
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Myocardial infarction in the past 6 months
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Current, active eating disorder as determined by chart review, investigator assessment, or subject history
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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
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Consuming a current diet described by the subject as vegetarian, vegan, very low-carbohydrate, or ketogenic
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Illicit drug use (not including marijuana)
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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)
Contacts and Locations
Locations
No locations specified.Sponsors and Collaborators
- University of Rochester
Investigators
- Principal Investigator: Thomas Campbell, MD, University of Rochester
Study Documents (Full-Text)
None provided.More Information
Publications
None provided.- RSRB 0007277