The Ability of Pecan Consumption to Improve Vascular Function and Reduce Chronic Disease Risk in Aging Adults

Background: To date, there are no published studies on the effects of pecans on vascular function following a high-fat meal.

Purpose: To examine the impact of daily pecan consumption for a 4-week period on vascular health and other markers of cardiovascular disease risk in aging adults.

Study Overview

• Status: Completed
• Conditions: Aging
• Intervention / Treatment: Dietary supplement: PECAN

Detailed Description

This will be a randomized, controlled trial in men and postmenopausal women (50-75y). Subjects will be randomized into one of the two study groups: a control group (CON) following their usual diet, or intervention group (PECAN) following their usual diet but also consuming 68g/day of pecans as a snack.

There will be 3 visits: A Screening visit and a baseline and post-diet intervention visit (4-weeks). Anthropometrics, questionnaires, a fasting blood sample, and fasting vascular measures will be collected at each visit. Subjects will participate in a saturated fatty acid meal challenge in which additional blood, vascular measurements will be collected.

Hypothesis: Daily pecan consumption will result in improved fasting blood lipids, vascular measures, antioxidant status, and appetite compared to the control group. Additionally, also the PECAN group will result in improved postprandial blood lipids and vascular measures compared to the control group.

• Study Type: Interventional
• Enrollment (Actual): 50
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Georgia
    • Athens, Georgia, United States, 30605
      • University of Georgia- Department of Foods and Nutrition

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 50 years to 75 years (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Men and postmenopausal women (without menses for 1 yr and follicle stimulating hormone > 30 IU/mL) between the ages of 50-75y
• Body mass indexes (BMI) between 18-34.9kg/m2

Exclusion Criteria:

• Nut consumption >2 servings/week or tree nut butter consumption >3 servings/week
• Pre-menopausal and menopausal women, hormone replacement therapy if less than 2 years
• Regularly exercise more than 3 h/week
• Weight gain or loss more than 5% of their body weight in the past 3 months
• Plans to begin a weight loss/exercise regimen during the trial
• Gastrointestinal surgeries, conditions or disorders
• History of medical or surgical events that could affect swallowing
• Chronic or metabolic diseases
• Previous MI, stroke, or cancer
• Fasting blood glucose levels greater than 126 mg/dL
• Blood pressure greater than 180/120 mmHg
• Medication use affecting digestion and absorption, metabolism
• Lipid-lowering medications
• Medications for diabetes, depression, or ADD/ADHD
• Regular use of medications known to affect endothelial function or blood vessel tone
• Blood pressure medication and steroid/hormone therapies
• Individuals on a medically prescribed or special diet
• Individuals with food allergies to foods specifically in the study
• Excessively use alcohol (greater than 3 drinks/d for men; greater than 2 drinks/d for women)
• Tobacco or nicotine use
• Individuals taking fish oil and omega-3 fatty acid supplements
• Significant head trauma or brain surgery
• A score >26 on the Beck's Depression Inventory II (BDI-II)
• A score <24 on the Mini-Mental State Examination (MMSE) will be excluded.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: PREVENTION
• Allocation: RANDOMIZED
• Interventional Model: PARALLEL
• Masking: NONE

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
NO_INTERVENTION: Control; Participants in this group avoid all nuts for 4-weeks
EXPERIMENTAL: PECAN; Participants in this group consume 68 g of pecans/d with no other changes to their habitual diet and avoid all other nuts.	Dietary supplement: PECAN; Raw pecan halves without other changes to their habitual diet.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fasting and postprandial Flow-Mediated Dilation from baseline to 4 weeks	Flow-Mediated Dilation %	Baseline and 4 weeks
Change in fasting and postprandial vessel diameter from baseline to 4 weeks	baseline diameter (mm) and peak dilation (mm)	Baseline and 4 weeks
Change in fasting and postprandial reactive hyperemia velocity from baseline to 4 weeks	Baseline velocity (cm/s) and reactive hyperemia velocity (cm/s)	Baseline and 4 weeks
Change in fasting and postprandial shear rate from baseline to 4 weeks	baseline shear rate (sec.-1) and reactive hyperemia shear rate (sec.-1)	Baseline and 4 weeks
Change in fasting and postprandial Continuous-Wave Near-Infrared Spectrometry from baseline to 4 weeks	O2 desaturation rate (%.sec-1), and O2 resaturation rate (%.sec-1)	Baseline and 4 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fasting blood lipids from baseline to 4 weeks	Total cholesterol (mg/dL), high-density lipoprotein (HDL) cholesterol (mg/dL), triglycerides (mg/dL), low-density lipoprotein (LDL) cholesterol (mg/dL), apolipoprotein B (mg/dL)	Baseline and 4 weeks
Change in baseline weight at 4 weeks	weight (kg)	Baseline and 4 weeks
Change in baseline waist and hip circumference	waist and hip circumference (cm)	Baseline and 4 weeks
Change in blood pressure from baseline to 4 weeks	Systolic and Diastolic Blood Pressure (mm Hg)	Baseline and 4 weeks
Change in baseline total body fat percentage at 4 weeks	total body fat percentage (%)	Baseline and 4 weeks
Change in fasting and postprandial insulin from baseline to 4 weeks	Insulin (uU/mL)	Baseline and 4 weeks
Change in fasting and postprandial antioxidants from baseline to 4 weeks	Total antioxidant capacity (uM trolox equivalents) measured via Oxygen Radical Absorbance Capacity (ORAC)	Baseline and 4 weeks
Change in fasting and postprandial lipid peroxidation from baseline to 4 weeks	Malondialdehyde (MDA) (uM) measured via Thiobarbituric acid reactive substances (TBARS) assay.	Baseline and 4 weeks
Change in fasting inflammation from baseline to 4 weeks	Interleukin-6 (pg/mL), C-reactive Protein (pg/mL), Tumor Necrosis Factor-α (pg/mL), Plasminogen Activator-1 (pg/mL)	Baseline and 4 weeks
Change in fasting and postprandial glucose and triglycerides from baseline to 4 weeks	Glucose (mg/dL) and triglycerides (mg/dL)	Baseline and 4 weeks
Change in fasting and postprandial peptide YY, cholecystokinin (CCK), and ghrelin from baseline to 4 weeks	Peptide YY (pg/mL), CCK (pg/mL), ghrelin (pg/mL)	Baseline and 4 weeks
Change in fasting and postprandial non-esterified free fatty acids (NEFA) from baseline to 4 weeks	NEFA (mEq/L)	Baseline and 4 weeks
Change in fasting and postprandial hunger and satiety from baseline to 4 weeks	Hunger, fullness, prospective consumption, and desire to eat measured via a Visual Analog Scale (VAS) (mm). The range of scores on the continuous VAS is between 0mm (no hunger, fullness, prospective consumption and desire to eat) and 100mm (the greatest feeling of hunger, fullness, prospective consumption and desire to eat)	Baseline and 4 weeks

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fasting and postprandial composite cognitive function from baseline to 4 weeks	NIH tool box- Cognitive Battery (NIHTB-CB) computed- theta score for the sum of all subtests	Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial.
Change in fasting and postprandial Cognitive Battery Motivation from baseline to 4 weeks	Visual Analogue Scale (VAS) (mm). This continuous scale is anchored by either no motivation (0mm) or extremely motivated (100mm).	Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial.
Change in fasting and postprandial NIHTB-CB Flanker Inhibitory Control and Attention Test, and Dimensional Change Card Sort Test from baseline to 4 weeks	NIHTB-CB computed scores ranging from 0-10; high score representing greater accuracy	Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial.
Change in fasting and postprandial NIHTB-CB Auditory Learning Test, Picture Sequence Memory Task and List Sorting Working Memory Test from baseline to 4 weeks	NIHTB-CB computed scores representing the number of correctly recalled items; higher scores indicating better memory.	Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial.
Change in Pittsburg Sleep Quality Index scores from baseline to 4 weeks	The scoring is out of 21 points, where a high score indicates poor sleep quality.	Baseline and 4 weeks
Change in State Trait Anxiety Inventory scores from baseline to 4 weeks	The scoring is out of 80 points, where high score indicates higher levels of anxiety.	Baseline and 4 weeks

Collaborators and Investigators

• Sponsor: University of Georgia
• Collaborators: American Pecan Council

Study record dates

Study Major Dates

• Study Start (ACTUAL): September 17, 2020
• Primary Completion (ACTUAL): April 16, 2022
• Study Completion (ACTUAL): April 16, 2022

Study Registration Dates

• First Submitted: April 30, 2020
• First Submitted That Met QC Criteria: May 7, 2020
• First Posted (ACTUAL): May 13, 2020

Study Record Updates

• Last Update Posted (ACTUAL): May 24, 2022
• Last Update Submitted That Met QC Criteria: May 17, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Disease Attributes; Chronic Disease
• Other Study ID Numbers: PROJECT00001978

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: The plan is to share group averages through publication.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No