Diet Quality, Pecans, and Cardiometabolic Health

Study Overview
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Brief Summary
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A three-period, randomized, crossover controlled feeding trial will be conducted to examine the effect of including 2 oz./day of pecans, as a snack, in a diet representative of average American intake, compared to a diet representative of average American intake devoid of nuts, and a healthy dietary pattern including 2 oz./day of pecans on markers of peripheral vascular health, lipids and lipoproteins, blood pressure, and glycemic control.

Detailed Description
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Participants will be randomized to each diet for 4-weeks with a minimum 2-week break between the diet periods. All caloric foods and beverages will be provided. Outcome assessments will be done at baseline and the end of each diet period.

Official Title
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Cardiometabolic Effects of Including Pecans as a Snack in Dietary Patterns That Vary in Diet Quality: a Randomized, Controlled Feeding, Crossover Study

Conditions
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Cardiovascular Diseases

Intervention / Treatment
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* Drug: Pecan
* Other: Average American Diet devoid of nuts


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: BMI ≥25 and ≤40 kg/m2 ≥ 1 criterion for metabolic syndrome (i.e. waist circumference ≥ 94 cm men or ≥80 cm women; triglycerides ≥150 mg/dL; HDL ≤ 40 mg/dL men or ≤50 mg/dL women; systolic blood pressure ≥130 mmHg or diastolic blood pressure ≥85 mmHg; fasting plasma glucose ≥100 mg/dL) at screening. non-smoking Exclusion Criteria: Current tobacco use or use within the previous 6 months Diagnosed diabetes or fasting glucose levels > 126 mg/dL at screening Systolic blood pressure >160 mm Hg or diastolic blood pressure > 100 mm Hg at screening. Use of anti-hypertensive, lipid lowering, glucose lowering drugs, steroids, or antibiotics in the previous month History of a cardiovascular event (heart attack, revascularization, stroke), or heart failure, liver, kidney, autoimmune diseases or inflammatory conditions such as gastrointestinal disorders or rheumatoid arthritis Use of supplements and botanicals known to affect study outcomes (e.g. psyllium, fish oil, soy lecithin, and phytoestrogens) and not willing to cease for the duration of the study Pregnancy, lactation or planning to become pregnant Consumption of >14 alcoholic drinks/week Intolerance/allergy/sensitivity to foods included in the study menus

Ages Eligible for Study
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Minimum Age: 25 Years
Maximum Age: 70 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Average American Diet<br>Diet representative of average American intake in terms of diet quality measured by the Healthy Eating Index-2015. | Other: Average American Diet devoid of nuts<br>* Diet mimicking usual American intake<br>|
| Active Comparator: Average American Diet + Pecans<br>Diet that approximates average American intake in terms of diet quality measured by the Healthy Eating Index-2015, but includes 2 oz./day of pecans. | Drug: Pecan<br>* Unsalted raw pecans incorporated in snack and meal recipes as part of a dietary pattern<br>|
| Active Comparator: Healthy Diet + Pecans<br>High diet quality, measured by Healthy Index-2015 score >95, and includes 2 oz./day of pecans. | Drug: Pecan<br>* Unsalted raw pecans incorporated in snack and meal recipes as part of a dietary pattern<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Flow mediated dilation | Measured by brachial ultrasound and expressed as percent artery dilation | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LDL-cholesterol concentration | Assessed from fasting blood draw expressed in mg/dL | 4 weeks | 
| HDL-cholesterol concentrations | Assessed from fasting blood draw expressed in mg/dL | 4 weeks | 
| Triglycerides | Assessed from fasting blood draw expressed in mg/dL | 4 weeks | 
| LDL lipoprotein subclasses | Assessed from fasting blood draw expressed in nmol/L | 4 weeks | 
| HDL lipoprotein subclasses | Assessed from fasting blood draw expressed in umol/L | 4 weeks | 
| Peripheral systolic and diastolic blood pressure | Blood pressure measured assessed using a SphymoCor Ecel (Atcor Medical) | 4 weeks | 
| Central systolic and diastolic blood pressure | Blood pressure measured assessed using a SphymoCor Ecel (Atcor Medical). | 4 weeks | 
| Carotid-femoral pulse wave velocity | A measure of arterial stiffness assessed using a SphymoCor Ecel (Atcor Medical). Expressed in meters/second. | 4 weeks | 
| Augmentation Index | A measure of arterial stiffness assessed using a SphymoCor Ecel (Atcor Medical). Expressed as a percentage. A higher percentage value is indicative of greater arterial stiffness. | 4 weeks | 
| Fasting plasma glucose concentration | Fasting blood glucose assessed by blood draw and expressed in mg/dL | 4 weeks | 
| Serum insulin concentration | Fasting serum insulin levels assessed by blood draw and expressed in micro IU/mL | 4 weeks |