Dietary Intake of Whole Walnuts in Adult Subjects Under Low Cardiovascular Risk (FitALA)

Investigation of Health Effects of Dietary Intake of Whole Walnuts in Adult Subjects Under Low Cardiovascular Risk Towards Established and Molecular Cardiovascular Risk Factors

This cross-over study investigates health effects of dietary intake of whole walnuts towards cardiovascular risk factors in adults under low cardiovascular risk.

Investigators hypothesize that daily intake of whole nuts as a replacement meal, would improve cardiovascular risk factors, including traditional risk factors and molecular biomarkers.

The participants are randomly assigned to receive either study treatment, or no treatment, and are crossed after five weeks.

The study subjects are instructed to continue with their habitual diet and physical activity.

Study Overview

• Status: Completed
• Conditions: Hypertension; Metabolic Syndrome; Cardiovascular Risk Factor
• Intervention / Treatment: Dietary supplement: Whole Walnuts

Detailed Description

Recent literature data raise important questions on the beneficial effect of dietary fats. Dietary intake of nuts, although with high caloric burden, is however characterized with high intake of fatty acids with known beneficial health effects. Those fatty acids include mono- (MUFA) and polyunsaturated fatty acids (PUFA), to whom beneficial health effects are ascribed.

Among nuts, walnuts are characterized with comparatively high levels of MUFA and PUFA, especially content of alpha-linolenic PUFA, considered essential fatty acid, since not synthesized endogenously in humans. Dietary intake of alpha-linolenic acid is shown to be inversely related with cardiovascular risk factors, both in interventional studies and epidemiological cohorts. Molecular background of alpha-linolenic actions is bidirectional, and includes the action itself, as well as beneficial endogenous conversion towards long-chain fatty acids, including eicosapentaenoic and docosahexaenoic fatty acid.

Although high caloric intake is indicated with intake of walnuts, literature data suggest that consumption of walnuts does not increase body weight.

Dietary intake of walnuts has been shown to decrease cholesterol fractions, triglycerides and apolipoproteins in adult population. Also, consumption of walnuts was associated with decrease in blood pressure.

The study design is cross-over, controlled, randomized nutritional intervention. The participants are randomly assigned to receive either study treatment, or no treatment, and are crossed after five weeks.

The study subjects are instructed to continue with their habitual diet and physical activity. Additionally, study subjects are instructed to avoid walnuts and nuts other then study treatment, during the complete study period of 10 weeks.

Sample size calculation was conducted by use of online calculators, and was based on the low density lipoprotein (LDL) cholesterol. Namely, in order to achieve decrease in 0.5 mmol/L, in a sample with projected standard deviation of 0.7 mmol/L, and type I and II errors being 0.2 and 0.05, respectively, 62 subjects are needed.

• Study Type: Interventional
• Enrollment (Actual): 52
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Serbia
  • Belgrade, Serbia, 11000
    • Center of Research Excellence in Nutrition and Metabolism, Institute for Medical Research, University of Belgrade

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

Presence of at least one of the following criteria, formerly assessed through routine medical examination:

• dyslipidemia, defined as the presence of either: elevated total cholesterol (>5.2 mmoL/L), and/or elevated LDL-cholesterol (>3.4 mmoL/L), and/or elevated triglycerides (>1.7 mmoL/L), and/or decreased HDL-cholesterol (<1.6 mmoL/L)
• elevated blood pressure (systolic/diastolic ≥120/80 mmHg), or regular anti-hypertension therapy

Exclusion Criteria:

• presence of allergy on any nuts
• presence of any chronic disease, excluding following conditions: hypertension and diabetes mellitus type 2
• smoking
• statin therapy
• pregnancy and/or lactation

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Prevention
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Walnut; At the beginning of the study, subjects are randomly assigned to receive either intervention treatment (whole walnuts) or no treatment (control arm). Treatment arm includes 56 g of whole walnuts daily.	Dietary supplement: Whole Walnuts; Intervention arm includes whole walnuts taken as dietary replacement meal during the day, and between breakfast and lunch, and/or lunch and dinner. Importantly, none of the main meals, including breakfast, lunch and dinner are to be replaced by study intervention, and the study subjects are instructed to do so. Walnuts are provided with the same producer at the Belgrade market.
No Intervention: Control; At the beginning of the study, subjects are randomly assigned to receive either intervention treatment (whole walnuts) or no treatment (control arm).

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in LDL-cholesterol	Changes in LDL-cholesterol measured by clinical bio-analyzer from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in Systolic Blood Pressure	Changes in Systolic Blood Pressure, from baseline to endpoint, measured office-based at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in Diastolic Blood Pressure	Changes in Diastolic Blood Pressure from baseline to endpoint, measured office-based at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Changes in HDL-cholesterol	Changes in HDL-cholesterol measured by clinical bio-analyzer from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in total cholesterol	Changes in total cholesterol measured by clinical bio-analyzer from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in triglycerides	Changes in triglycerides measured by clinical bio-analyzer from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in glucose metabolism biomarkers	Changes in glucose biomarkers measured by clinical bio-analyzer from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in renal function parameters	Changes in renal function parameters measured by clinical bio-analyzer from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in liver function parameters	Changes in liver function parameters measured by clinical bio-analyzer from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in body weight	Changes in body weight measured by bio-impedance analyzer, from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in waist circumference	Changes in waist circumference, from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in percent of total body fat	Changes in percent of total body fat measured by bio-impedance analyzer, from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Level of Physical Activity	Level of physical activity is assessed by use of standardized Physical Activity Questionnaire.	Baseline
Psychological parameters	Psychological parameters are assessed by use of standardized questionnaire for self-assessment of psychological implications of daily activities related to cardiovascular health .	5 weeks
Changes in hematological parameters	Changes in hematological, from baseline to endpoint, measured by hematological clinical analyzer at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in number of leukocyte cells	Changes in number of leukocyte cells, from baseline to endpoint, measured by hematological clinical analyzer at the following timepoints: 0 (baseline), 5 and 10 weeks.	Baseline, 5 weeks, 10 weeks
Changes in total caloric intake	Changes in total caloric intake, from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks. Total caloric intake is measured by use of standardized dietary questionnaire namely 24-hour Dietary Recall.	Baseline, 5 weeks, 10 weeks
Changes in caloric intake of fats	Changes in caloric intake of fats, from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks. The caloric intake is measured by use of standardized dietary questionnaire, namely 24-hour Dietary Recall.	Baseline, 5 weeks, 10 weeks
Changes in caloric intake of carbohydrates	Changes in caloric intake of carbohydrates, from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks. The caloric intake is measured by use of standardized dietary questionnaire, namely 24-hour Dietary Recall.	Baseline, 5 weeks, 10 weeks
Changes in caloric intake of vitamin D	Changes in caloric intake of vitamin D, from baseline to endpoint, measured at the following timepoints: 0 (baseline), 5 and 10 weeks. The caloric intake is measured by use of standardized dietary questionnaire, namely 24-hour Dietary Recall.	Baseline, 5 weeks, 10 weeks

Collaborators and Investigators

• Sponsor: University of Belgrade
• Collaborators: Centre of Research Excellence in Nutrition and Metabolism
• Investigators: Principal Investigator: Maria Glibetic, Prof, Center of Research Excellence in Nutrition and Metabolism, Institute for Medical Resaerch

Study record dates

Study Major Dates

• Study Start (Actual): April 21, 2017
• Primary Completion (Actual): July 15, 2017
• Study Completion (Actual): July 15, 2017

Study Registration Dates

• First Submitted: July 17, 2017
• First Submitted That Met QC Criteria: July 21, 2017
• First Posted (Actual): July 24, 2017

Study Record Updates

• Last Update Posted (Actual): July 24, 2017
• Last Update Submitted That Met QC Criteria: July 21, 2017
• Last Verified: July 1, 2017

More Information

Terms related to this study

• Keywords: Cholesterol; Blood Pressure; Triglycerides; Walnuts
• Additional Relevant MeSH Terms: Glucose Metabolism Disorders; Metabolic Diseases; Insulin Resistance; Hyperinsulinism; Metabolic Syndrome
• Other Study ID Numbers: EO120/2017

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No