Cardiometabolic Effects of Pecans as a Snack

Cardiometabolic Effects of Including Pecans as a Snack to Improve Diet Quality: a Randomized Controlled Study

A randomized, 2-arm, parallel trial will be conducted to examine the effect of pecans on markers of peripheral vascular health, lipids and lipoproteins, blood pressure, and glycemic control.

Study Overview

• Status: Completed
• Conditions: Cardiovascular Diseases
• Intervention / Treatment: Drug: Pecans; Other: Usual Care

Detailed Description

A randomized, 2-arm, parallel trial will be conducted to examine the effect of including 2 oz./day of pecans, as a snack, compared to a diet typically consumed by participants intake (devoid of nuts) on markers of peripheral vascular health, lipids and lipoproteins, blood pressure, and glycemic control. Participants will be randomized to pecans or control for 12-weeks. Outcome assessments will be measured at baseline and 12-weeks.

• Study Type: Interventional
• Enrollment (Actual): 138
• Phase: Phase 2

Contacts and Locations

Study Locations

• United States
  • Pennsylvania
    • University Park, Pennsylvania, United States, 16802
      • Penn State University

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

• BMI 25-40 kg/m2
• ≥ 1 criterion for metabolic syndrome (i.e., waist circumference ≥ 94 cm men or ≥ 80 cm women; triglycerides ≥150 mg/dL; HDL-cholesterol ≤ 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

Exclusion Criteria:

• Current use of tobacco-containing products or (≤6 months) cessation
• Allergy/sensitivity/intolerance/dislike of study foods
• Women who are pregnant, lactating, planning to become pregnant or have given birth in the past year
• Individuals who have had a cardiovascular event (heart attack, revascularization, stroke), or have a history of heart failure, liver, kidney, autoimmune diseases or inflammatory conditions such as gastrointestinal disorders or rheumatoid arthritis.
• Type 1 or type 2 diabetes
• Unstable weight ≥10% body weight for 6 months prior to enrollment
• Systolic Blood pressure >160 mmHg for systolic pressure and/or diastolic blood pressure >/100 mmHg for diastolic pressure at screening
• Fasting blood glucose ≥126 mg/dL at screening
• Triglycerides ≥350 mg/dL at screening
• Taking any medications known to affect lipids, blood pressure, or blood glucose levels
• Diagnosed inflammatory conditions or taking prescribed , taking any chronic anti-inflammatory medications (>1 time per week over the past 3 months)
• Use of antibiotics within the prior 8 weeks
• Taking supplements (e.g., psyllium, fish oil, soy lecithin, and phytoestrogens) and botanicals known to affect study outcomes and not willing to cease for the duration of the study
• Individuals consuming >14 alcoholic drinks/week, and not willing to avoid alcohol consumption for 48 hours prior to test visit
• Pre-menopausal women who do not have a regular menstrual cycle of 25-35 days
• PI discretion

Study Plan

How is the study designed?

Design Details

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

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Pecan Group; Participants will consume their usual diet, but replace one snack with unsalted raw pecans incorporated as a snack	Drug: Pecans; Participants will receive 2 oz of pecans daily to replace a typical snack and continue consuming their usual diet for 12 weeks.
Active Comparator: Usual Care Group; Participants will consume their usual diet devoid of nuts	Other: Usual Care; Participants will receive grocery vouchers and continue consuming their usual diet for 12 weeks.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Flow Mediated Dilation	Measured by brachial ultrasound and expressed as percentage points of change in arterial diameter	12 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Triglycerides	Assessed from fasting blood draw expressed in mg/dL	12 weeks
LDL-cholesterol Concentration	Assessed from fasting blood draw expressed in mg/dL	12 weeks
HDL-cholesterol Concentration	Assessed from fasting blood draw expressed in mg/dL	12 weeks
LDL Lipoprotein Subclasses	Assessed from fasting blood draw expressed in nmol/L. Data were log transformed and back transformed to improve residual distribution; Measure Description: LDL particle size classifications are as follows: 22-25.5 nm is small, 25.6-26.5 nm medium, and 26.6-28.5 nm large. Typically, smaller LDL is associated with increased cardiovascular risk compared to larger.	12 weeks
HDL Lipoprotein Subclasses	Assessed from fasting blood draw expressed in µmol/L; Measure Description: Size classifications of HDL subclasses are as follows: large (size 9.4-14.0 nm), medium (8.3-9.3 nm), and small (7.3-8.2 nm). Higher levels of large HDL may be inversely related to cardiovascular risk.	12 weeks
Brachial Systolic and Diastolic Blood Pressure	Blood pressure measured assessed using a SphygmoCor Xcel (Atcor Medical)	12 weeks
Central Systolic and Diastolic Blood Pressure	Blood pressure measured assessed using a SphygmoCor Xcel (Atcor Medical)	12 weeks
Carotid-femoral Pulse Wave Velocity	A measure of arterial stiffness assessed using a SphygmoCor Xcel (Atcor Medical). Expressed in meters/second. Higher values indicate greater arterial stiffness	12 weeks
Augmentation Index@75bpm	A measure of arterial stiffness assessed using a SphygmoCor Xcel (Atcor Medical). Expressed as a percentage. A higher percentage value is indicative of greater arterial stiffness. Measure Description: Augmentation index is a measure of arterial stiffening that correlates with CVD risk. Higher augmentation index, used as a surrogate for wave reflection, is indicative of additional load on the left ventricle. Augmentation index is calculated as augmentation pressure/pulse pressure*100 to provide a percent. We utilized the Sphymocor Xcel for this measure. We used standardized augmentation index at 75 bpm for heart rate.	12 weeks
Fasting Plasma Glucose Concentration	Fasting blood glucose assessed by blood draw and expressed in mg/dL	12 weeks
Serum Insulin Concentration	Fasting serum insulin levels assessed by blood draw and expressed in micro IU/m	12 weeks
HbA1c	HbA1c assessed in whole blood collected during fasting	12-weeks
Diet Quality: Healthy Eating Index 2020	Diet quality measured by 24-hour recalls will be assessed using Health Eating Index 2020 (HEI-2020) scores range from 0-100 with 100 indicating perfect adherence to dietary guidelines and 0 indicating no adherence. The HEI-2020 includes 13 components; 9 components are adequacy (i.e., consuming more results in a higher score), and 4 are moderation (i.e., consuming less results in a higher score). The HEI-2020 was calculated with the Statistical Analysis System (SAS) code from the National Cancer Institute.	12-weeks
Total Cholesterol Concentration	Assessed from fasting blood draw expressed in mg/dL	12-weeks
LDL Subclasses	LDL subclasses with normal distribution; Measure Description: LDL particle size classifications are as follows: 22-25.5 nm is small, 25.6-26.5 nm medium, and 26.6-28.5 nm large. Typically, smaller LDL is associated with increased cardiovascular risk compared to larger.	12 weeks
HDL Subclass-Large	Measure was log transformed and back transformed to improve distribution; results for large HDL subclass are presented; Measure Description: Size classifications of HDL subclasses are as follows: large (size 9.4-14.0 nm), medium (8.3-9.3 nm), and small (7.3-8.2 nm). Higher levels of large HDL may be inversely related to cardiovascular risk.	12 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	12 weeks

Collaborators and Investigators

• Sponsor: Penn State University
• Collaborators: American Pecan Council
• Investigators: Principal Investigator: Kristina Petersen, PhD, Penn State University

Study record dates

Study Major Dates

• Study Start (Actual): August 15, 2022
• Primary Completion (Actual): March 1, 2024
• Study Completion (Actual): March 1, 2024

Study Registration Dates

• First Submitted: September 28, 2021
• First Submitted That Met QC Criteria: September 28, 2021
• First Posted (Actual): October 8, 2021

Study Record Updates

• Last Update Posted (Actual): March 25, 2025
• Last Update Submitted That Met QC Criteria: February 4, 2025
• Last Verified: February 1, 2025

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Cardiovascular Diseases
• Other Study ID Numbers: PKE 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: Yes
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No