Dose Response Effects of Pecan Consumption

NCT05949879 | Completed

• 1 other identifier: PROJECT00007288
• Study Type: interventional
• Target: 108
• Locations: 1 country
• Sites: 1

Brief Summary

The bioactive compounds contained in tree nuts have been shown to beneficially affect cardiometabolic health outcomes. Pecans contain more total phenols, sterols, and flavonoids than any other tree nut. They also are a rich source of polyunsaturated fatty acids (PUFAs), fiber, vitamin A, vitamin E, folic acid, calcium, magnesium, phosphorus, potassium, and zinc. These bioactive components in pecans are likely the reason for the previously documented improvements in cardiometabolic health. The specific aims of this study are to:

• Examine the effect of pecan consumption at doses of 6%, 13%, and 20% of total energy needs on fasting and postprandial blood lipids.
• Examine the effect of pecan consumption at doses of 6%, 13%, and 20% of total energy needs on plasma markers associated with overall health.
• Examine the effect of pecan consumption at doses of 6%, 13%, and 20% of total energy needs on subjective and physiologic postprandial measures of hunger and satiety. Participants will be asked to:
• Consume pecans daily for 28 days or maintain their current habitual diet.
• Attend three short weekly visits for fasting blood craws, body measurements, and collect their next week's supply of study materials.
• Attend two longer (5 h) testing visits which include consuming a standard breakfast meal and having their blood drawn periodically before and after breakfast. Researchers will compare pecan LOW, pecan MID, pecan HIGH, and the Control group to examine the physiologic effects of incorporating various dosages of pecans into one's diet.

Conditions

Dyslipidemias; Overweight and Obesity; Nutrition, Healthy

Outcome Measures

Primary Outcomes (15)

• Change in fasting serum lipoprotein and cholesterol concentrations

  The concentration of fasting serum total cholesterol, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and apolipoprotein B (mg/dl).

  Baseline, 4 weeks

• Change in fasting serum lipoprotein particle numbers

  The number of particles of low-density lipoproteins (LDL), LDL small, HDL large, LDL medium, lipoprotein (a) (nmol/L).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma triglyceride concentrations

  The concentration of plasma triglycerides before and after the high saturated fat meal challenge at both pre-and post-intervention visits (mg/dL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma non-esterified fatty acid (NEFA) concentrations

  The concentration of plasma NEFAs before and after the high saturated fat meal challenge at both pre-and post-intervention visits (mEq/L).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma glucose concentrations

  The concentration of plasma glucose before and after the high saturated fat meal challenge at both pre-and post-intervention visits (mg/dL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma insulin concentrations

  The concentration of plasma insulin before and after the high saturated fat meal challenge at both pre-and post-intervention visits (uU/mL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma appetite control hormones concentrations

  The concentration of plasma appetite control hormones before and after the high saturated fat meal challenge at both pre-and post-intervention visits. Appetite control hormones include Cholecystokinin (CCK), Peptide YY (PYY), and Ghrelin (pg/mL).

  Baseline, 4 weeks

• Change in fasting and postprandial subjective feelings related to appetite

  Visual analog scale ratings of feelings related to appetite before and after the high saturated fat meal challenge at both pre-and post-intervention visits. Subjective feelings of hunger, fullness, desire to eat, prospective consumption, and a composite appetite score are measured by visual analog scales (mm).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma Malondialdehyde (MDA)

  The concentration of MDA before and after the high saturated fat meal challenge at both pre-and post-intervention visits (nmol/mL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma total antioxidant capacity

  Total antioxidant capacity before and after the high saturated fat meal challenge at both pre-and post-intervention visits (U/mL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma antioxidant parameters

  Glutathione peroxidase activity, superoxide dismutase activity, and glutathione-s-transferase activity before and after the high saturated fat meal challenge at both pre-and post-intervention visits (U/mL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma inflammatory cytokine concentrations

  The concentration of interleukin-1 beta, C reactive protein, tumor necrosis factor-alpha, and interleukin-6 before and after the high saturated fat meal challenge at both pre-and post-intervention visits (pg/mL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma markers of coagulation potential

  The concentration of plasminogen activator inhibitor-1 and tissue factor before and after the high saturated fat meal challenge at both pre-and post-intervention visits (pg/mL).

  Baseline, 4 weeks

• Change in fasting and postprandial plasma angiopoietin-like (ANGPTL) proteins

  The concentration of ANGPTL 3, ANGPTL 4, and ANGPTL 8 before and after the high saturated fat meal challenge at both pre-and post-intervention visits (ng/mL).

  Baseline, 4 weeks

• Change in fasting insulin resistance metrics

  Homeostatic Model Assessment for Insulin Resistance (HOMA-IR) and Homeostatic Model Assessment for β-cell function (HOMA-B) will be calculated from fasting insulin and glucose measures before and after the 28-day intervention.

  Baseline, 4 weeks

Secondary Outcomes (7)

• Change in fasting serum hepatic enzymes

  Baseline, 4 weeks

• Change in fasting serum hepatic proteins

  Baseline, 4 weeks

• Change in fasting serum bilirubin

  Baseline, 4 weeks

• Change in additional fasting and postprandial plasma inflammatory cytokine concentrations

  Baseline, 4 weeks

• Change in additional fasting and postprandial plasma markers of coagulation potential

  Baseline, 4 weeks

Other Outcomes (15)

• Change in blood pressure

  Baseline, 4 weeks

• Change in body weight

  Baseline, 4 weeks

• Change in body composition

  Baseline, 4 weeks

Study Arms (4)

Pecan LOW

EXPERIMENTAL

Participants are given pecans and instructed on how to substitute study foods into their diet to maintain caloric balance.

Other: Pecan LOW

Pecan MID

EXPERIMENTAL

Participants are given pecans and instructed on how to substitute study foods into their diet to maintain caloric balance.

Other: Pecan MID

Pecan HIGH

EXPERIMENTAL

Participants are given pecans and instructed on how to substitute study foods into their diet to maintain caloric balance.

Other: Pecan HIGH

CONTROL

EXPERIMENTAL

Participants are asked to maintain their current habitual diet and avoid any tree nut/peanut consumption for the entire 28-day intervention period.

Other: CONTROL

Interventions

Pecan LOW OTHER

Participants are provided with a quantity of pecans that delivers 6% of the participant's estimated energy needs for 28 days.

Pecan LOW

Pecan MID OTHER

Participants are provided with a quantity of pecans that delivers 13% of the participant's estimated energy needs for 28 days.

Pecan MID

Pecan HIGH OTHER

Participants are provided with a quantity of pecans that delivers 20% of the participant's estimated energy needs for 28 days.

Pecan HIGH

CONTROL OTHER

Participants are asked to maintain their current habitual diet and to avoid any tree nut/peanut consumption for the entire 28-day intervention period.

CONTROL

Eligibility Criteria

• Age: 30 Years - 75 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• to 75-year-old men and women at increased risk of cardiovascular disease. Increased risk of cardiovascular disease will be defined by either elevated cholesterol profiles or overweight/obesity.
• Elevated cholesterol profiles will be defined as: "Borderline High" and/or "at risk" in two or more of the following variables (total cholesterol: 180-239 mg/dL, LDL cholesterol 110- 159 mg/dL, triglycerides 130-199 mg/dL) --or---"High" in total cholesterol (240 mg/dL and higher), LDL (160 mg/dL or higher), or triglycerides (between 200-350 mg/dl).
• Overweight/obesity will be defined by body mass index (overweight \> 28 kg/m2 or obesity 30 kg/m2 or greater).

You may not qualify if:

• Probable familial hypercholesterolemia, defined by: total cholesterol greater than 290 mg/dL or LDL levels greater than 190 mg/dL plus a family history of myocardial infarction (MI) before 50 years of age in a 2nd-degree relative or below age 60 in a 1st-degree relative
• Alcohol intake \>3 drinks/d for males or \>2 drinks/d for females
• Individuals with food allergies/sensitivities to foods provided in the study, including tree nuts, gluten, and or lactose/dairy
• Individuals who regularly consume nuts and/or nut butter (defined as consumption of \>2 servings (\~56g) of tree nuts, nuts, or nut butter (e.g., peanut butter, almond butter) per week
• Individuals adhering to special diets, including, but not limited to, the ketogenic diet, intermittent fasting, vegetarian diet, or carbohydrate-restricted diets
• Plans to begin a weight loss/exercise regime during the trial
• Weight gain or loss of more than 5% of their body weight in the past 3 months
• History of previous or current renal or bowel disease
• Females who are currently pregnant or lactating
• Individuals participating in \>3 hours/week of exercise
• Women on hormone replacement therapy for \<2 years
• Fasting glucose \>126 mg/dL
• Blood pressure \>180/120 mmHg
• History of medical or surgical events that could affect digestion or swallowing
• Gastrointestinal surgery, atherosclerosis, or bleeding disorders

Sponsors & Collaborators

• University of Georgia: lead

Study Sites (1)

University of Georgia

Athens, Georgia, 30602, United States

Location

Related Publications (1)

• Guadagni AJ, Paton CM, Cooper JA. Dose-Response Effects of Pecan Consumption on Blood Lipid Profiles in Adults with Excess Body Weight and/or Dyslipidemia: a Randomized Controlled Trial. J Nutr. 2026 Apr;156(4):101396. doi: 10.1016/j.tjnut.2026.101396. Epub 2026 Feb 4.

  PMID: 41651071 DERIVED

MeSH Terms

Conditions

Dyslipidemias; Overweight; Obesity

Condition Hierarchy (Ancestors)

Lipid Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Overnutrition; Nutrition Disorders; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms

Study Officials

• Jamie A Cooper, Ph.D.

  University of Georgia

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Masking Details: Participants are blinded to which group they are in and what oil they are receiving.
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Professor, Director of UGA Obesity Initiative

Model Details: Four groups of 28-day parallel feeding trials with three groups receiving different amounts of pecans (low, mid, high) and one group serving as control (instructed to maintain their current habitual diet and avoid any nut consumption for the 28-day intervention).

Study Record Dates

• First Submitted: June 28, 2023
• First Posted: July 18, 2023
• Study Start: August 1, 2023
• Primary Completion: April 14, 2025
• Study Completion: April 14, 2025
• Last Updated: May 4, 2026

Record last verified: 2026-04

Locations

US (1)