Trial Outcomes & Findings for Postprandial Effects of Walnut Components Versus Whole Walnuts on Cardiovascular Disease (CVD) Risk Reduction (NCT NCT00938340)

NCT ID: NCT00938340

Last Updated: 2023-08-21

Results Overview

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and FRAP was measured at 0, 60, 120, 240, and 360 min. The FRAP assay was used to determine the reducing ability of plasma in a redox-linked colorimetric reaction. Plasma was incubated with the FRAP reagent at room temperature for 1 h and the absorbance at 593 nm was then recorded. Trolox was used as a reference to construct a standard curve to calculate the FRAP value of the samples. The FRAP assay measures lipophilic and hydrophilic antioxidants (total antioxidant capacity), both of which are present in walnuts.

Recruitment status

COMPLETED

Study phase

NA

Target enrollment

20 participants

Primary outcome timeframe

AUC values were calculated with the trapezoidal rule, using the respective fasting baseline value as the line of reference. Measured at 0 to 360 min (baseline to 360min post meal) for each of the 4 walnut treatments.

Results posted on

2023-08-21

Participant Flow

Participants were recruited through advertisements in the local newspaper and university e-mails from April 2008 to October 2008.

Of the individuals (n=246) who were contacted and screened with a semi-structured telephone interview, 50 qualified and were scheduled for a screening visit at the Penn State General Clinical Research Center. After written informed consent was obtained, a fasting blood sample was drawn. Eligible participants (n=20) were randomized to the study.

Participant milestones

Participant milestones
Measure
Walnut Intervention
Four different treatments were provided to each participant in a randomized-crossover fashion: ground whole walnuts (85 g), walnut skins (5.6 g) derived from whole walnuts, walnut oil (51 g) extracted from whole walnuts, or skinless, defatted walnut nutmeat (34 g) from whole walnuts. Each treatment was incorporated into an inert food carrier.
Overall Study
STARTED
20
Overall Study
Received Whole Walnut Intervention
16
Overall Study
Received Walnut Nutmeat Intervention
19
Overall Study
Received Walnut Skins Intervention
15
Overall Study
Received Walnut Oil Intervention
15
Overall Study
COMPLETED
15
Overall Study
NOT COMPLETED
5

Reasons for withdrawal

Reasons for withdrawal
Measure
Walnut Intervention
Four different treatments were provided to each participant in a randomized-crossover fashion: ground whole walnuts (85 g), walnut skins (5.6 g) derived from whole walnuts, walnut oil (51 g) extracted from whole walnuts, or skinless, defatted walnut nutmeat (34 g) from whole walnuts. Each treatment was incorporated into an inert food carrier.
Overall Study
Withdrawal by Subject
3
Overall Study
Protocol Violation
1
Overall Study
Adverse Event
1

Baseline Characteristics

Postprandial Effects of Walnut Components Versus Whole Walnuts on Cardiovascular Disease (CVD) Risk Reduction

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
All Completed Participants (n=15)
n=15 Participants
Whole walnut (85 g) Walnut skins (5.6 g) Walnut oil (51 g) Defatted walnut nutmeat (34 g)
Age, Continuous
49 years
STANDARD_DEVIATION 9 • n=5 Participants
Sex: Female, Male
Female
9 Participants
n=5 Participants
Sex: Female, Male
Male
6 Participants
n=5 Participants
Body mass index
29 kg/m^2
STANDARD_DEVIATION 4 • n=5 Participants
Systolic blood pressure
119 mm Hg
STANDARD_DEVIATION 10 • n=5 Participants
Diastolic blood pressure
76 mm Hg
STANDARD_DEVIATION 9 • n=5 Participants
Total cholesterol
5.0 mmol/L
STANDARD_DEVIATION 0.7 • n=5 Participants
LDL-cholesterol
3.4 mmol/L
STANDARD_DEVIATION 0.6 • n=5 Participants
HDL-cholesterol
1.1 mmol/L
STANDARD_DEVIATION 0.3 • n=5 Participants
Triglycerides
1.2 mmol/L
STANDARD_DEVIATION 0.5 • n=5 Participants
Ferric reducing antioxidant potential (FRAP)
1148 umol TE/L
STANDARD_DEVIATION 195 • n=5 Participants
Total thiols
0.40 mmol/L
STANDARD_DEVIATION 0.11 • n=5 Participants
Malondialdehyde (MDA)
0.75 umol/L
STANDARD_DEVIATION 0.32 • n=5 Participants
Reactive hyperemia index (RHI)
2.0 ratio
STANDARD_DEVIATION 0.6 • n=5 Participants
Framingham reactive hyperemia index (fRHI)
0.43 ln(ratio)
STANDARD_DEVIATION 0.39 • n=5 Participants

PRIMARY outcome

Timeframe: AUC values were calculated with the trapezoidal rule, using the respective fasting baseline value as the line of reference. Measured at 0 to 360 min (baseline to 360min post meal) for each of the 4 walnut treatments.

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and FRAP was measured at 0, 60, 120, 240, and 360 min. The FRAP assay was used to determine the reducing ability of plasma in a redox-linked colorimetric reaction. Plasma was incubated with the FRAP reagent at room temperature for 1 h and the absorbance at 593 nm was then recorded. Trolox was used as a reference to construct a standard curve to calculate the FRAP value of the samples. The FRAP assay measures lipophilic and hydrophilic antioxidants (total antioxidant capacity), both of which are present in walnuts.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=15 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on the Ferric Reducing Antioxidant Potential (FRAP) Changes in Response to 4 Walnut Treatments
-26 umol Trolox equivalents (TE)*min/L
Standard Error 46
28 umol Trolox equivalents (TE)*min/L
Standard Error 47
9 umol Trolox equivalents (TE)*min/L
Standard Error 47
-135 umol Trolox equivalents (TE)*min/L
Standard Error 51

PRIMARY outcome

Timeframe: Change from baseline for each timepoint (60, 120, 240, 360 min)

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) blood sample was collected. Participants then had 15 min to consume 1 of 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and FRAP was measured at 0, 60, 120, 240, and 360 min. The FRAP assay was used to determine the reducing ability of plasma in a redox-linked colorimetric reaction. Plasma was incubated with the FRAP reagent at room temperature for 1 h and the absorbance at 593 nm was then recorded. Trolox was used as a reference to construct a standard curve to calculate the FRAP value of the samples. The FRAP assay measures lipophilic and hydrophilic antioxidants (total antioxidant capacity), both of which are present in walnuts. Several blood samples (n=3) could not be obtained/measured (walnut skin group at 360 min, walnut oil group at 120 min, whole walnut group at 240 min).

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
n=15 Participants
Walnut Skins (120 Min)
n=15 Participants
Walnut Skins (240 Min)
n=15 Participants
Walnut Skins (360 Min)
n=14 Participants
Walnut Oil (60 Min)
n=15 Participants
Walnut Oil (120 Min)
n=14 Participants
Walnut Oil (240 Min)
n=15 Participants
Walnut Oil (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
n=15 Participants
Defatted Walnut Nutmeat (120 Min)
n=15 Participants
Defatted Walnut Nutmeat (240 Min)
n=15 Participants
Defatted Walnut Nutmeat (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment by Timepoint on the Ferric Reducing Antioxidant Potential (FRAP) Changes in Response to 4 Walnut Treatments
69 umol Trolox equivalents (TE)/L
Standard Error 63
-34 umol Trolox equivalents (TE)/L
Standard Error 63
-65 umol Trolox equivalents (TE)/L
Standard Error 64
-75 umol Trolox equivalents (TE)/L
Standard Error 63
-4 umol Trolox equivalents (TE)/L
Standard Error 64
10 umol Trolox equivalents (TE)/L
Standard Error 64
7 umol Trolox equivalents (TE)/L
Standard Error 64
98 umol Trolox equivalents (TE)/L
Standard Error 65
-10 umol Trolox equivalents (TE)/L
Standard Error 64
5 umol Trolox equivalents (TE)/L
Standard Error 65
53 umol Trolox equivalents (TE)/L
Standard Error 64
-13 umol Trolox equivalents (TE)/L
Standard Error 64
-139 umol Trolox equivalents (TE)/L
Standard Error 66
-92 umol Trolox equivalents (TE)/L
Standard Error 66
-175 umol Trolox equivalents (TE)/L
Standard Error 66
-134 umol Trolox equivalents (TE)/L
Standard Error 66

PRIMARY outcome

Timeframe: AUC values were calculated with the trapezoidal rule, using the respective fasting baseline value as the line of reference. Measured at 0 to 360 min (baseline to 360min post meal) for each of the 4 walnut treatments.

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and total thiols measured at 0, 60, 120, 240, and 360 min. Total thiols in plasma were determined by the following methods: an aliquot of EDTA plasma was mixed with Tris-EDTA buffer, followed by addition of 10 mmol/L 2,2-dithiobisnitrobenzoic acid and methanol. After incubation at room temperature for 15 min and centrifugation, the absorbance of the supernatant was measured at 412 nm.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=15 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on the Changes in Total Thiol Response to 4 Walnut Treatments
0.024 mmol*min/L
Standard Error 0.014
0.010 mmol*min/L
Standard Error 0.015
0.011 mmol*min/L
Standard Error 0.014
0.026 mmol*min/L
Standard Error 0.017

PRIMARY outcome

Timeframe: Change from baseline for each timepoint (60, 120, 240, 360 min)

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and total thiols measured at 0, 60, 120, 240, and 360 min. Total thiols in plasma were determined by the following methods: an aliquot of EDTA plasma was mixed with Tris-EDTA buffer, followed by addition of 10 mmol/L 2,2-dithiobisnitrobenzoic acid and methanol. After incubation at room temperature for 15 min and centrifugation, the absorbance of the supernatant was measured at 412 nm. Several blood samples (n=3) could not be obtained/measured (walnut skin group at 360 min, walnut oil group at 120 min, whole walnut group at 240 min).

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
n=15 Participants
Walnut Skins (120 Min)
n=15 Participants
Walnut Skins (240 Min)
n=15 Participants
Walnut Skins (360 Min)
n=14 Participants
Walnut Oil (60 Min)
n=15 Participants
Walnut Oil (120 Min)
n=14 Participants
Walnut Oil (240 Min)
n=15 Participants
Walnut Oil (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
n=15 Participants
Defatted Walnut Nutmeat (120 Min)
n=15 Participants
Defatted Walnut Nutmeat (240 Min)
n=15 Participants
Defatted Walnut Nutmeat (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment by Timepoint on Total Thiol Changes in Response to 4 Walnut Treatments
0.051 mmol/L
Standard Error 0.017
0.035 mmol/L
Standard Error 0.017
0.001 mmol/L
Standard Error 0.021
0.010 mmol/L
Standard Error 0.022
0.018 mmol/L
Standard Error 0.018
-0.004 mmol/L
Standard Error 0.018
0.005 mmol/L
Standard Error 0.021
0.019 mmol/L
Standard Error 0.023
0.022 mmol/L
Standard Error 0.017
0.029 mmol/L
Standard Error 0.018
0.003 mmol/L
Standard Error 0.020
-0.010 mmol/L
Standard Error 0.023
0.038 mmol/L
Standard Error 0.019
0.037 mmol/L
Standard Error 0.020
0.022 mmol/L
Standard Error 0.022
0.008 mmol/L
Standard Error 0.024

PRIMARY outcome

Timeframe: AUC values were calculated with the trapezoidal rule, using the respective fasting baseline value as the line of reference. Measured at 0 to 360 min (baseline to 360min post meal) for each of the 4 walnut treatments.

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and MDA measured at 0, 60, 120, 240, and 360 min. Plasma MDA was measured by an Agilent 1100 HPLC system with fluorometric detection.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=15 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on the Changes in Malondialdehyde (MDA) Response to 4 Walnut Treatments
-0.015 umol*min/L
Standard Error 0.036
0.004 umol*min/L
Standard Error 0.036
0.041 umol*min/L
Standard Error 0.036
-0.001 umol*min/L
Standard Error 0.037

PRIMARY outcome

Timeframe: Change from baseline for each timepoint (60, 120, 240, 360 min)

On the day of each test, participants arrived at the clinic after a 12-h overnight fast. A baseline (0 min) blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and MDA measured at 0, 60, 120, 240, and 360 min. Plasma MDA was measured by an Agilent 1100 HPLC system with fluorometric detection. Several blood samples (n=2) could not be obtained (walnut oil group at 120 min and whole walnut group at 240 min).

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
n=15 Participants
Walnut Skins (120 Min)
n=15 Participants
Walnut Skins (240 Min)
n=15 Participants
Walnut Skins (360 Min)
n=15 Participants
Walnut Oil (60 Min)
n=15 Participants
Walnut Oil (120 Min)
n=14 Participants
Walnut Oil (240 Min)
n=15 Participants
Walnut Oil (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
n=15 Participants
Defatted Walnut Nutmeat (120 Min)
n=15 Participants
Defatted Walnut Nutmeat (240 Min)
n=15 Participants
Defatted Walnut Nutmeat (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment by Timepoint on Malondialdehyde (MDA) Changes in Response to 4 Walnut Treatments
-0.081 umol/L
Standard Error 0.056
-0.018 umol/L
Standard Error 0.054
-0.022 umol/L
Standard Error 0.061
0.063 umol/L
Standard Error 0.075
-0.054 umol/L
Standard Error 0.056
0.047 umol/L
Standard Error 0.054
-0.012 umol/L
Standard Error 0.060
0.049 umol/L
Standard Error 0.075
0.057 umol/L
Standard Error 0.056
0.032 umol/L
Standard Error 0.056
-0.021 umol/L
Standard Error 0.060
0.111 umol/L
Standard Error 0.075
-0.017 umol/L
Standard Error 0.056
0.004 umol/L
Standard Error 0.054
-0.002 umol/L
Standard Error 0.060
-0.032 umol/L
Standard Error 0.075

PRIMARY outcome

Timeframe: AUC values were calculated with the trapezoidal rule, using the respective fasting baseline value as the line of reference. Measured at 0 to 360 min (baseline to 360min post meal) for each of the 4 walnut treatments.

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and CRP measured at 0, 60, 120, 240, and 360 min. Serum CRP was measured by latex-enhanced immunonephelometry.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=15 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on the Changes in C-reactive Protein (CRP) Response to 4 Walnut Treatments
0.10 mg*min/L
Standard Error 0.07
0.01 mg*min/L
Standard Error 0.07
0.20 mg*min/L
Standard Error 0.07
0.12 mg*min/L
Standard Error 0.07

PRIMARY outcome

Timeframe: Change from baseline for each timepoint (60, 120, 240, 360 min)

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and CRP measured at 0, 60, 120, 240, and 360 min. Serum CRP was measured by latex-enhanced immunonephelometry. Several blood samples (n=3) could not be obtained/measured (walnut oil/120 min, whole walnut/240 min, and walnut skin/360 min).

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
n=15 Participants
Walnut Skins (120 Min)
n=15 Participants
Walnut Skins (240 Min)
n=15 Participants
Walnut Skins (360 Min)
n=14 Participants
Walnut Oil (60 Min)
n=15 Participants
Walnut Oil (120 Min)
n=14 Participants
Walnut Oil (240 Min)
n=15 Participants
Walnut Oil (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
n=15 Participants
Defatted Walnut Nutmeat (120 Min)
n=15 Participants
Defatted Walnut Nutmeat (240 Min)
n=15 Participants
Defatted Walnut Nutmeat (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment by Timepoint on C-reactive Protein (CRP) Changes in Response to 4 Walnut Treatments
0.12 mg/L
Standard Error 0.05
0.08 mg/L
Standard Error 0.05
0.06 mg/L
Standard Error 0.09
0.16 mg/L
Standard Error 0.12
0.04 mg/L
Standard Error 0.06
0.03 mg/L
Standard Error 0.05
0.04 mg/L
Standard Error 0.09
-0.06 mg/L
Standard Error 0.13
0.20 mg/L
Standard Error 0.06
0.20 mg/L
Standard Error 0.05
0.18 mg/L
Standard Error 0.09
0.25 mg/L
Standard Error 0.13
0.12 mg/L
Standard Error 0.06
0.09 mg/L
Standard Error 0.06
0.08 mg/L
Standard Error 0.09
0.20 mg/L
Standard Error 0.13

SECONDARY outcome

Timeframe: Change from baseline at 240 min

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. At baseline the endothelial function test was performed using pulse amplitude tonometry (PAT) (Itamar Medical). Participants then had 15 min to consume 1 of the 4 walnut test meals. The endothelial function test was performed again at 240 min postmeal. RHI was calculated as the ratio of the average pulse wave amplitude during hyperemia (60 to 120 s of the post occlusion period) to the average pulse wave amplitude during baseline in the occluded hand divided by the same values in the control hand and then multiplied by a baseline correction factor. No endothelial function test data available for one participant within the walnut oil group and one within the defatted walnut nutmeat group.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=14 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on Reactive Hyperemia Index (RHI) Changes in Response to 4 Walnut Treatments
-0.19 ratio
Standard Error 0.09
-0.26 ratio
Standard Error 0.09
0.07 ratio
Standard Error 0.09
-0.09 ratio
Standard Error 0.09

SECONDARY outcome

Timeframe: Change from baseline at 240 min

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. At baseline the endothelial function test was performed using pulse amplitude tonometry (PAT) (Itamar Medical). Participants then had 15 min to consume 1 of the 4 walnut test meals. The endothelial function test was performed again at 240 min postmeal. fRHI is an alternative calculation derived from the same raw data (as RHI) and differs in that it uses the period from 90 to 120 s of postocclusion hyperemia, does not incorporate a baseline correction factor, and has a natural log transformation applied to the resulting ratio. No endothelial function test data available for one participant within the walnut oil group and one within the defatted walnut nutmeat group.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=14 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on Framingham Reactive Hyperemia Index (fRHI) Changes in Response to 4 Walnut Treatments
-0.14 ln(ratio)
Standard Error 0.07
-0.14 ln(ratio)
Standard Error 0.07
0.09 ln(ratio)
Standard Error 0.07
-0.02 ln(ratio)
Standard Error 0.07

SECONDARY outcome

Timeframe: Change from baseline at 240 min

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. At baseline the endothelial function test was performed using pulse amplitude tonometry (PAT) (Itamar Medical). Participants then had 15 min to consume 1 of the 4 walnut test meals. The endothelial function test was performed again at 240 min postmeal. No endothelial function test data available for one participant within the walnut oil group and one within the defatted walnut nutmeat group.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=14 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on Heart Rate (HR) Changes in Response to 4 Walnut Treatments
3.9 beats/minute
Standard Error 1.4
0.2 beats/minute
Standard Error 1.4
4.4 beats/minute
Standard Error 1.4
1.9 beats/minute
Standard Error 1.5

SECONDARY outcome

Timeframe: Change from baseline at 240 min

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. At baseline the endothelial function test was performed using pulse amplitude tonometry (PAT) (Itamar Medical). Participants then had 15 min to consume 1 of the 4 walnut test meals. The endothelial function test was performed again at 240 min postmeal. AI is a measure of vascular stiffness (pulse wave reflection) that is calculated from the shape of the pulse wave recorded during baseline. No endothelial function test data was available for one participant within the walnut oil group and one within the defatted walnut nutmeat group.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=14 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on Augmentation Index (AI) Changes in Response to 4 Walnut Treatments
-6.6 Percent change
Standard Error 3.1
-1.4 Percent change
Standard Error 3.2
-2.6 Percent change
Standard Error 3.2
-4.0 Percent change
Standard Error 3.7

SECONDARY outcome

Timeframe: Change from baseline at 240 min

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. At baseline the endothelial function test was performed using pulse amplitude tonometry (PAT) (Itamar Medical). Participants then had 15 min to consume 1 of the 4 walnut test meals. The endothelial function test was performed again at 240 min postmeal. AI is a measure of vascular stiffness (pulse wave reflection) that is calculated from the shape of the pulse wave recorded during baseline. AI can be adjusted to a heart rate of 75 beats/min (AI\_75) to correct for the independent effect of heart rate on this measure.No endothelial function test data was available for one participant within the walnut oil group and one within the defatted walnut nutmeat group.

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=14 Participants
Defatted Walnut Nutmeat (34 g)
n=14 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on Augmentation Index Standardized to a Heart Rate of 75 Beats/Min (AI_75) Changes in Response to 4 Walnut Treatments
-4.0 Percent change
Standard Error 2.7
-1.2 Percent change
Standard Error 2.8
-0.1 Percent change
Standard Error 2.9
-2.9 Percent change
Standard Error 3.3

SECONDARY outcome

Timeframe: AUC values were calculated with the trapezoidal rule, using the respective fasting baseline value as the line of reference. Measured at 0 to 360 min (baseline to 360min post meal) for each of the 4 walnut treatments.

Population: All participants who completed each of the 4 treatment arms

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and TG was measured at 0, 30, 60, 120, 240, and 360 min. TG were determined by standard colorimetric and enzymatic procedures with commercially available kits (Alfa Wassermann).

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=15 Participants
Defatted Walnut Nutmeat (34 g)
n=15 Participants
Walnut Skins (60 Min)
Walnut Skins (120 Min)
Walnut Skins (240 Min)
Walnut Skins (360 Min)
Walnut Oil (60 Min)
Walnut Oil (120 Min)
Walnut Oil (240 Min)
Walnut Oil (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Defatted Walnut Nutmeat (60 Min)
Defatted Walnut Nutmeat (120 Min)
Defatted Walnut Nutmeat (240 Min)
Defatted Walnut Nutmeat (360 Min)
Main Effect of Treatment on the Triglyceride (TG) Changes in Response to 4 Walnut Treatments
0.24 mmol*min/L
Standard Error 0.05
0.05 mmol*min/L
Standard Error 0.05
0.24 mmol*min/L
Standard Error 0.05
0.09 mmol*min/L
Standard Error 0.06

SECONDARY outcome

Timeframe: Change from baseline for each timepoint (30, 60, 120, 240, 360 min)

On the day of each test, participants arrived at the General Clinical Research Center after a 12-h overnight fast. A baseline (0 min) fasting blood sample was collected. Participants then had 15 min to consume 1 of the 4 walnut test meals. Blood samples (∼30 mL) were subsequently taken at 30, 60, 120, 240, and 360 min following the meal and TG was measured at 0, 30, 60, 120, 240, and 360 min. TG were determined by standard colorimetric and enzymatic procedures with commercially available kits (Alfa Wassermann). Several blood samples (n=4) could not be obtained/measured \[walnut skin group at 360 min (n=1), walnut oil group at 120 min (n=2), whole walnut group at 240 min(n=1)\].

Outcome measures

Outcome measures
Measure
Whole Walnut (85 g)
n=15 Participants
Walnut Skins (5.6 g)
n=15 Participants
Walnut Oil (51 g)
n=15 Participants
Defatted Walnut Nutmeat (34 g)
n=14 Participants
Walnut Skins (60 Min)
n=15 Participants
Walnut Skins (120 Min)
n=15 Participants
Walnut Skins (240 Min)
n=15 Participants
Walnut Skins (360 Min)
n=15 Participants
Walnut Oil (60 Min)
n=15 Participants
Walnut Oil (120 Min)
n=15 Participants
Walnut Oil (240 Min)
n=15 Participants
Walnut Oil (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
n=13 Participants
Defatted Walnut Nutmeat (120 Min)
n=15 Participants
Defatted Walnut Nutmeat (240 Min)
n=15 Participants
Defatted Walnut Nutmeat (360 Min)
n=15 Participants
Defatted Walnut Nutmeat (60 Min)
n=15 Participants
Defatted Walnut Nutmeat (120 Min)
n=15 Participants
Defatted Walnut Nutmeat (240 Min)
n=14 Participants
Defatted Walnut Nutmeat (360 Min)
n=15 Participants
Main Effect of Treatment by Timepoint on Triglyceride (TG) Changes in Response to 4 Walnut Treatments
0.04 mmol/L
Standard Error 0.04
0.13 mmol/L
Standard Error 0.05
0.32 mmol/L
Standard Error 0.07
0.47 mmol/L
Standard Error 0.08
0.24 mmol/L
Standard Error 0.07
0.05 mmol/L
Standard Error 0.04
0.05 mmol/L
Standard Error 0.05
0.02 mmol/L
Standard Error 0.07
0.06 mmol/L
Standard Error 0.08
0.08 mmol/L
Standard Error 0.07
0.08 mmol/L
Standard Error 0.04
0.10 mmol/L
Standard Error 0.05
0.41 mmol/L
Standard Error 0.07
0.47 mmol/L
Standard Error 0.08
0.14 mmol/L
Standard Error 0.07
0.05 mmol/L
Standard Error 0.05
0.02 mmol/L
Standard Error 0.06
0.06 mmol/L
Standard Error 0.07
0.17 mmol/L
Standard Error 0.09
0.13 mmol/L
Standard Error 0.08

Adverse Events

Walnut Oil

Serious events: 0 serious events
Other events: 9 other events
Deaths: 0 deaths

Whole Walnut

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Walnut Skins

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Defatted Walnut Nutmeat

Serious events: 0 serious events
Other events: 0 other events
Deaths: 0 deaths

Serious adverse events

Adverse event data not reported

Other adverse events

Other adverse events
Measure
Walnut Oil
n=15 participants at risk
Whole Walnut
n=15 participants at risk
Walnut Skins
n=15 participants at risk
Defatted Walnut Nutmeat
n=15 participants at risk
Gastrointestinal disorders
Diarrhea
60.0%
9/15 • Number of events 9 • During the intervention (0 to 360 min)
0.00%
0/15 • During the intervention (0 to 360 min)
0.00%
0/15 • During the intervention (0 to 360 min)
0.00%
0/15 • During the intervention (0 to 360 min)

Additional Information

Penny Kris-Etherton

Penn State University

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place