The Metabolic Effect of Walnuts in Healthy Subjects

Study Overview
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Brief Summary
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The objectives of the proposed study are to assess whether the metabolic effects of walnut consumption depends on which food components the walnuts substitute (i.e. carbohydrates; saturated fatty acids) and whether it is important to consume walnuts as snacks or with meals.

Detailed Description
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The objectives of the proposed study are to assess whether the metabolic effects of walnut consumption depends on which food components the walnuts substitute (i.e. carbohydrates; saturated fatty acids) and whether it is important to consume walnuts as snacks or with meals. The metabolic effects of walnut consumption may not only relate to the ingested walnuts but also to what is not eaten when walnuts are consumed. We want to evaluate whether the metabolic changes are more pronounced if study participants are instructed to reduce carbohydrates or saturated fatty acids to remain on an isocaloric diet. In a third group we will test what food is omitted if no specific instructions are given. Furthermore half of the subjects in each group will be instructed to eat walnuts with meals and half as snacks.

Official Title
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The Metabolic Effect of Walnut Consumption in Healthy Men and Healthy Postmenopausal Women Substituting Walnuts for Different Food Components

Conditions
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Lipid Metabolism Disorders

Intervention / Treatment
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* Other: walnuts


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Postmenopausal healthy women and healthy men Age >50 yrs Written informed consent prior to study participation Exclusion Criteria: Known allergy to nuts Evidence of alcohol (women >70g/week, men >140g/week), tabacco or drug abuse Obesity ≥35 kg/m2 Diabetes mellitus Hypertension >140/90 mmHg or history of hypertension LDL-cholesterol >190 mg/dl, Triglycerides > 350 mg/dl History of atherosclerotic disease Liver disease of any etiology Kidney disease of any etiology (GFR < 60 ml/min/1.73) Uncontrolled thyroid disease or other endocrine diseases Acute or chronic inflammatory diseases Active malignancy Current or previous (within 3 months) treatment with antidiabetic drugs, hypolipidemic drugs, antihypertensive drugs, anti-inflammatory drugs, vitamin E, hormonal replacement therapy major surgical intervention within 3 months (or planned)

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: walnut-CH<br>Western type diet including walnuts (43g/day); Walnuts substitute carbohydrates | Other: walnuts<br>* consumption of 43 g walnuts per day<br>|
| Experimental: Walnut-SFA<br>Western type diet including walnuts (43g/day); Walnuts substitute saturated fatty acids | Other: walnuts<br>* consumption of 43 g walnuts per day<br>|
| Experimental: Walnut-LIB<br>Western type diet including walnuts (43g/day); no specific recommendation | Other: walnuts<br>* consumption of 43 g walnuts per day<br>|
| No Intervention: Control<br>Isocaloric western type diet w/o nuts, nut butters or nut oils of any kind | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Non-HDL-cholesterol |  | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| LDL-cholesterol |  | 8 weeks | 
| total-cholesterol |  | 8 weeks | 
| apoB |  | 8 weeks | 
| triglycerides |  | 8 weeks | 
| fasting glucose |  | 8 weeks | 
| HOMA index |  | 8 weeks | 
| caloric intake |  | 8 weeks | 
| ratio CH:fat:protein |  | 8 weeks | 
| ratio SFA:MUFA:PUFA |  | 8 weeks |