Diet Quality, Pecans, and Cardiometabolic Health

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

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.

Study Overview

• Status: Withdrawn
• Conditions: Cardiovascular Diseases
• Intervention / Treatment: Other: Average American Diet devoid of nuts; Drug: Pecan

Detailed Description

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.

• Study Type: Interventional
• Phase: Phase 2

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 25 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

Description

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

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Average American Diet; 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; Diet mimicking usual American intake
Active Comparator: Average American Diet + Pecans; 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; Unsalted raw pecans incorporated in snack and meal recipes as part of a dietary pattern
Active Comparator: Healthy Diet + Pecans; High diet quality, measured by Healthy Index-2015 score >95, and includes 2 oz./day of pecans.	Drug: Pecan; Unsalted raw pecans incorporated in snack and meal recipes as part of a dietary pattern

What is the study measuring?

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

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in the composition of the gut microbiota	Abundance measured using 16 s rRNA sequencing	4 weeks

Collaborators and Investigators

• Sponsor: Penn State University

Study record dates

Study Major Dates

• Study Start (Estimated): May 1, 2021
• Primary Completion (Estimated): July 1, 2022
• Study Completion (Estimated): July 1, 2022

Study Registration Dates

• First Submitted: July 22, 2020
• First Submitted That Met QC Criteria: July 22, 2020
• First Posted (Actual): July 27, 2020

Study Record Updates

• Last Update Posted (Actual): August 18, 2023
• Last Update Submitted That Met QC Criteria: August 15, 2023
• Last Verified: August 1, 2023

More Information

Terms related to this study

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

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

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