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The Effect of Plant-based Diets (Vegetarian and Vegan) on Endothelial Function and Atherogenic Parameters

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details. Identifier: NCT02153138
Recruitment Status : Unknown
Verified May 2014 by Tel-Aviv Sourasky Medical Center.
Recruitment status was:  Not yet recruiting
First Posted : June 2, 2014
Last Update Posted : June 2, 2014
Information provided by (Responsible Party):
Tel-Aviv Sourasky Medical Center

Brief Summary:
The investigators' hypothesis is that a plant-based diet may be beneficial if nutritional deficiencies will be corrected. The aims of the present proposal are to 1) study endothelial functions of subjects on well-defined vegetarian/vegan diets compared to age and sex matched omnivores (controls), and 2) study the differences in energy expenditure, body composition, overnight substrate utilization, blood work results, and levels of intracellular reactive oxygen species (ROS) and of adhesion molecules on the different diets.

Condition or disease Intervention/treatment Phase
Other Endothelial Dystrophy Device: Endo-pat 2000 Device: carotid intima media thickness Ultrasound Device: Dexa- Bone densitometer & Bone ultrasonometer System Not Applicable

Detailed Description:

The serious doubts about the nutritional adequacy of vegetarian diets in the past were essentially put to rest by recent studies that suggested that plant-based diets are healthy and associated with lower risk of several chronic diseases. Nevertheless, various nutritional deficiencies have been identified, and it has been shown that individuals who follow different types of vegetarian/vegan diets may not experience the same effects on their health.

Working Hypothesis

  1. Vegetarian/vegan diets will promote protection against cardiovascular risk factors if supplemented with possibly deficient nutrients.
  2. There will a further protective effect and a greater number of differences between subjects following a vegetarian diet compared to those following a vegan diet.
  3. Higher energy expenditure and lower and different caloric intake will promote a favorable difference in body composition (lower body fat) via a different substrate utilization expressed in the measured respiratory quotient (RQ).
  4. Extra- and intracellular free radicals will be higher in subjects who adhere to vegetarian/vegan diets compared to omnivores.

Aims of the study

  1. To study the effect of vegetarian/vegan diets on endothelial functions after correcting for modifying factors.
  2. To study the effect of the above-mentioned plant-based diets on carotid intima-media thickness.
  3. To study the differences in body composition, resting energy expenditure and over-night substrate utilization between the different diets.
  4. To study the intracellular ROS of subjects following different diets.

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 150 participants
Allocation: N/A
Intervention Model: Single Group Assignment
Masking: None (Open Label)
Primary Purpose: Health Services Research
Study Start Date : July 2014
Estimated Primary Completion Date : May 2015
Estimated Study Completion Date : September 2015

Resource links provided by the National Library of Medicine

MedlinePlus related topics: Vegetarian Diet

Intervention Details:
  • Device: Endo-pat 2000

    The endo peripheral arterial tonometry (PAT) provides an index of endothelial function in two forms:

    1. The reactive hyperemia index (RHI) is the post-to-preocclusion PAT signal ratio in the occluded side, normalized to the control side and further corrected for baseline vascular tone.
    2. The logarithm RHI (LnRHI) is s similar index as RHI after natural log transformation with a matched cutoff. LnRHI provides better double-sided distribution than RHI and one that is closer to normal distribution
  • Device: carotid intima media thickness Ultrasound
    cIMT is the distance between the intimal-luminal interface and the medial-adventitial interface. It will be studied by B-mode ultrasonography of the extracranial carotid arteries. A duplex system with a 7-10 megahertz (MHz) linear array multi-frequency transducer will be used.
  • Device: Dexa- Bone densitometer & Bone ultrasonometer System
    A means of measuring bone mineral density and body composition by a dual energy X-ray absorptiometry (DEXA) machine

Primary Outcome Measures :
  1. carotid intima-media thickness (cIMT) [ Time Frame: 1 year ]
    measure the differences in the thickness of the carotid between the different diet group

Secondary Outcome Measures :
  1. body composition [ Time Frame: 1-year ]
    Measure the differences in body composition ( fat %, lean body mass) between the different diet groups

Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.

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Ages Eligible for Study:   35 Years to 50 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • over 5 years' adherence to any type of diet
  • age range 35-50 years
  • BMI ≤32

Exclusion Criteria:

  • smoking
  • type I and II diabetes
  • liver and kidney impairments
  • cardiovascular diseases
  • patients with tumors
  • patients on medications which may affect cardiovascular parameters (including 5 phosphodiesterase inhibitors, beta blockers, ACE inhibitors and others)
  • BMI >32 kg/m2.

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its identifier (NCT number): NCT02153138

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Contact: Nachum Vaisman, MD 972-524-266-596

Sponsors and Collaborators
Tel-Aviv Sourasky Medical Center
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Principal Investigator: Nachum Vaisman, MD Tel-Aviv Sourasky Medical Center
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Responsible Party: Tel-Aviv Sourasky Medical Center Identifier: NCT02153138    
Other Study ID Numbers: TASMC-14-VN-0085-CTIL
First Posted: June 2, 2014    Key Record Dates
Last Update Posted: June 2, 2014
Last Verified: May 2014
Keywords provided by Tel-Aviv Sourasky Medical Center:
vegetarian diet
cardiovascular diseases
endothelial function
carotid intima-media thickness