Vegetable Consumption in Relation to Health

Study Overview
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Brief Summary
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Rationale: Consumption of vegetables is generally considered to be associated with several positive effects on health. Vegetables are a heterogeneous group of our diet which is rich in bio-actives. The vegetables contain a range of vitamins, minerals, dietary fibres and phytochemicals like potassium, flavonoids, carotenoids, and vitamin C. The recommended intake of vegetables by the Dutch Health Council is 200 grams daily (Health Council, 2006). Health in this project is defined as the possibility of a subject to change and adapt easily in response to a certain challenge. Healthy subjects show resilience in different physiological processes related to oxidative stress, metabolic stress, neurological stress and inflammatory stress. The reaction/response to a challenge might be changed when subjects have consumed more or less vegetables and have an improved health status. The response might also differentiate between subjects differing in BMI (healthy weight versus overweight/obese). Supplementation of vegetables will be provided in two conditions: a low and a high daily intake (50 versus 200 grams daily). An intervention known to have positive effects on health is weight loss. This will be studied in relation to health (the reaction to the challenge test) as well. A beneficial effect is present when 5% improvement of health markers is shown with vegetable supplementation, similar as is known from weight loss studies. Objective: The primary objective of the present study is to set-up a methodology to investigate health based on the resilience to challenge. A secondary objective is the effectiveness of the challenge concept with a food intervention. The vegetable supplementation study is a first example to test the challenge concept. Therefore, vegetable consumption according to the recommendations of the Dutch Health Council of 200 grams of vegetables daily will be studied with an exercise challenge test, to investigate the beneficial 'health' effects.

Detailed Description
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Study design: The study is designed as a randomized, cross-over and parallel, open study. Study population: The number of subjects participating in the study will be 32, healthy, lean and obese men, aged between 18-45 years. Intervention: each intervention lasts four weeks: High Vegetable treatment: consumption of 200 grams of vegetables daily; Low Vegetable treatment: consumption of 50 grams of vegetables daily; An energy restricted diet intervention with the habitual vegetable consumption. Main study parameters/endpoints: A 'challenge test' will be used as a physical stress test to examine whether subjects show more or less resilience to the test. The reaction and recovery of the human system to the exercise test may be used as indicators of health status on different biological analyses (transcriptomics; metabolomics; rules based medicine pm). Different analyses to measure oxidative stress will be performed. Also standard health biomarkers will be determined to examine the intervention effects.

Official Title
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Beneficial Effects of Vegetable Consumption and a Diet Intervention on Health in Lean and Obese Men.

Conditions
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Health, Obesity, Oxidative Stress

Intervention / Treatment
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* Dietary Supplement: Vegetables
* Dietary Supplement: energy restriction


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Healthy as assessed by the health and lifestyle questionnaire, (P8374 F02; in Dutch) physical examination results of the pre-study laboratory tests Males aged between 18 and 45 years at Day 01 of the study Body Mass Index (BMI): for the lean : between 20 and 25 kg/m2; obese between 30 and 35 kg/m2 Normal Dutch eating habits as assessed by P8374 F02 Used to consume vegetables daily and liking vegetables (P8374 F02 and F06) Physically able to perform a maximal cycling exercise test Voluntary participation Having given written informed consent Willing to comply with the study procedures Appropriate veins for blood sampling according to TNO Willing to accept use of all nameless data, including publication, and the confidential use and storage of all data for at least 15 years Willing to accept the disclosure of the financial benefit of participation in the study to the authorities concerned. Exclusion Criteria: Participation in any clinical trial including blood sampling and/or administration of substances up to 90 days before Day 01 of this study Participation in any non-invasive clinical trial up to 30 days before Day 01 of this study, including no blood sampling and/or oral, intravenous, or inhalatory administration of substances Having a history of medical or surgical events that may significantly affect the study outcome, including cardiovascular disease or hypertension and/or (food) allergy Using prescribed medication or taking pain killers on a regular basis (judged by the medical investigator) ; Smoking Exercise regularly and exceed the Dutch Standard of Healthy Physical Activity of 2.5 hours/week Alcohol consumption > 28 units/week Reported unexplained weight loss or gain of > 2 kg in the month prior to the pre-study screening Reported slimming or medically prescribed diet Recent blood donation (<1 month prior to the start of the study) Not willing to give up blood donation during the study Personnel of TNO Quality of Life, their partner and their first and second degree relatives Not having a general practitioner Not willing to accept information-transfer concerning participation in the study, or information regarding his health, like laboratory results, findings at anamnesis or physical examination and eventual adverse events to and from his general practitioner.

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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Male

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: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: High vegetable dose<br>Consumption of 200 grams of vegetables daily, for four weeks. | Dietary Supplement: Vegetables<br>* 200 or 50 grams of vegetables daily for four weeks<br>|
| Experimental: Low vegetable dose<br>Consumption of 50 grams of vegetables daily, for four weeks. | Dietary Supplement: Vegetables<br>* 200 or 50 grams of vegetables daily for four weeks<br>|
| Active Comparator: Weight loss interventio<br>Consumption of - 1000 kcal daily, for four weeks to be used as a positive control for the vegetables interventions. | Dietary Supplement: energy restriction<br>* Consume about 1000 kcal less daily, for four weeks, as a positive control to the vegetables interventions.<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Investigate whether the maximal exercise performance test is a good concept for a challenge test, to examine 'health'. Health is defined as the ability to adapt in different circumstances. |  | after 4 weeks intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Compare outcomes on the exercise test after high or low vegetable consumption and after weight loss. Differences are expected between the lean and obese subjects. |  | after four weeks of intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Health, Obesity, Oxidative stress, Challenge concept, Vegetables