Healthy
Conditions
Brief summary
Walnuts are a nutrient dense food, but most health research is on English walnuts (EW). Black walnuts (BW) contain a different antioxidant and fatty acid profile, and more protein, compared to EW. The purpose of the study was to compare postprandial responses following the consumption of 3 breakfast meals containing either butter (control), BW, or EW.
Detailed description
This study was a randomized, double-blind control trial consisting of 3 study visits for 3 different treatments. The treatments were high-fat breakfast muffins containing either butter (control), black walnuts, or English walnuts. The investigators recruited healthy, normal-weight adults between the ages of 15 and 45y. Study visits were completed in a random order with at least 72 hours between each visit. Anthropometrics, questionnaires, and fasting and postprandial blood samples were collected at each visit. Hypothesis: The walnut-containing meals would mitigate post-meal increases in glucose, insulin, triglycerides (TG), and lipid peroxidation while improving all measures of subjective appetite and TAC compared to the traditional meal without nuts.
Interventions
OTHERControl
Participants in this group received a traditional muffin with butter as the predominant source of fat.
OTHERBlack walnut
Participants in this group received a muffin in which part of the butter was substituted out for black walnuts.
OTHEREnglish walnut
Participants in this group received a muffin in which part of the butter was substituted out for English walnuts.
Sponsors
University of Georgia
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
OTHER
Masking
DOUBLE (Subject, Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
Inclusion criteria
* Healthy adult men and women * Normal-weight (body mass index = 18-24.9kg/m2)
Exclusion criteria
* Allergies to test meal ingredients (gluten, eggs, or nuts) * Medication/supplement usage * Chronic disease * Pregnancy or plans to become pregnant * Special diets * Tobacco use
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in triglycerides (TG) and glucose responses | Change from baseline to 3 hours postprandially | TG (mg/dL) and glucose (mg/dL) |
| Change in lipid peroxidation | Change from baseline to 3 hours postprandially | Malondialdehyde (MDA) (uM) measured via Thiobarbituric acid reactive substances (TBARS) assay |
| Change in total antioxidant capacity | Change from baseline to 3 hours postprandially | Total antioxidant capacity (uM trolox equivalents) measured via Oxygen Radical Absorbance Capacity (ORAC) assay. |
| Change in insulin | Change from baseline to 3 hours postprandially | Insulin (uU/mL) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in angiopoietin-like proteins-3 (ANGPTL3) and -4 (ANGPTL4) responses | Change from baseline to 3 hours postprandially | ANGPTL3 (pg/mL) and ANGPTL4 (pg/mL) |
| Change in hunger and satiety responses | Change from baseline to 3 hours postprandially | 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 0-100 mm. Zero represents no hunger, fullness, prospective consumption, and desire to eat, while 100 represents the greatest feeling of these outcomes. |
Countries
United States
Outcome results
None listed