Aging
Conditions
Brief summary
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.
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.
Interventions
DIETARY_SUPPLEMENTPECAN
Raw pecan halves without other changes to their habitual diet.
Sponsors
American Pecan Council
University of Georgia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Eligibility
Sex/Gender
ALL
Age
50 Years to 75 Years
Healthy volunteers
Yes
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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in fasting and postprandial shear rate from baseline to 4 weeks | Baseline and 4 weeks | baseline shear rate (sec.-1) and reactive hyperemia shear rate (sec.-1) |
| Change in fasting and postprandial reactive hyperemia velocity from baseline to 4 weeks | Baseline and 4 weeks | Baseline velocity (cm/s) and reactive hyperemia velocity (cm/s) |
| Change in fasting and postprandial vessel diameter from baseline to 4 weeks | Baseline and 4 weeks | baseline diameter (mm) and peak dilation (mm) |
| Change in fasting and postprandial Flow-Mediated Dilation from baseline to 4 weeks | Baseline and 4 weeks | Flow-Mediated Dilation % |
| Change in fasting and postprandial Continuous-Wave Near-Infrared Spectrometry from baseline to 4 weeks | Baseline and 4 weeks | O2 desaturation rate (%.sec-1), and O2 resaturation rate (%.sec-1) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in baseline total body fat percentage at 4 weeks | Baseline and 4 weeks | total body fat percentage (%) |
| Change in fasting and postprandial insulin from baseline to 4 weeks | Baseline and 4 weeks | Insulin (uU/mL) |
| Change in fasting and postprandial antioxidants from baseline to 4 weeks | Baseline and 4 weeks | Total antioxidant capacity (uM trolox equivalents) measured via Oxygen Radical Absorbance Capacity (ORAC) |
| Change in fasting blood lipids from baseline to 4 weeks | Baseline and 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) |
| Change in baseline weight at 4 weeks | Baseline and 4 weeks | weight (kg) |
| Change in baseline waist and hip circumference | Baseline and 4 weeks | waist and hip circumference (cm) |
| Change in blood pressure from baseline to 4 weeks | Baseline and 4 weeks | Systolic and Diastolic Blood Pressure (mm Hg) |
| Change in fasting and postprandial lipid peroxidation from baseline to 4 weeks | Baseline and 4 weeks | Malondialdehyde (MDA) (uM) measured via Thiobarbituric acid reactive substances (TBARS) assay. |
| Change in fasting inflammation from baseline to 4 weeks | Baseline and 4 weeks | Interleukin-6 (pg/mL), C-reactive Protein (pg/mL), Tumor Necrosis Factor-α (pg/mL), Plasminogen Activator-1 (pg/mL) |
| Change in fasting and postprandial glucose and triglycerides from baseline to 4 weeks | Baseline and 4 weeks | Glucose (mg/dL) and triglycerides (mg/dL) |
| Change in fasting and postprandial peptide YY, cholecystokinin (CCK), and ghrelin from baseline to 4 weeks | Baseline and 4 weeks | Peptide YY (pg/mL), CCK (pg/mL), ghrelin (pg/mL) |
| Change in fasting and postprandial non-esterified free fatty acids (NEFA) from baseline to 4 weeks | Baseline and 4 weeks | NEFA (mEq/L) |
| Change in fasting and postprandial hunger and satiety from baseline to 4 weeks | Baseline and 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) |
Other
| Measure | Time frame | Description |
|---|---|---|
| Change in fasting and postprandial composite cognitive function from baseline to 4 weeks | Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial. | NIH tool box- Cognitive Battery (NIHTB-CB) computed- theta score for the sum of all subtests |
| Change in fasting and postprandial Cognitive Battery Motivation from baseline to 4 weeks | Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial. | Visual Analogue Scale (VAS) (mm). This continuous scale is anchored by either no motivation (0mm) or extremely motivated (100mm). |
| Change in State Trait Anxiety Inventory scores from baseline to 4 weeks | Baseline and 4 weeks | The scoring is out of 80 points, where high score indicates higher levels of anxiety. |
| Change in Pittsburg Sleep Quality Index scores from baseline to 4 weeks | Baseline and 4 weeks | The scoring is out of 21 points, where a high score indicates poor sleep quality. |
| 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 | Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial. | NIHTB-CB computed scores representing the number of correctly recalled items; higher scores indicating better memory. |
| Change in fasting and postprandial NIHTB-CB Flanker Inhibitory Control and Attention Test, and Dimensional Change Card Sort Test from baseline to 4 weeks | Baseline and 4 weeks. Measured at fasting, and 30 minutes and 3.5 hours postprandial. | NIHTB-CB computed scores ranging from 0-10; high score representing greater accuracy |
Countries
United States
Outcome results
None listed