Creatine, Carnitine and Carnosine in Vegetarians

October 25, 2018 updated by: University Ghent

Effect of a 6-month Vegetarian Diet in Omnivorous Women on Body Creatine, Carnitine and Carnosine Stores

Balanced vegetarian diets are popular and contain health-promoting characteristics. A balanced lacto-ovo-vegetarian diet differs in nutrient intake from an omnivorous diet, e.g. by increased intake of fibre, magnesium and antioxidants, but lower intake of omega-3 fatty acids and vitamin B12. However, the impact of reduced to near absent intake of carnitine, carnosine and creatine in a vegetarian diet is less well established and could be relevant in relation to muscle function, exercise capacity and sports performance. Few longitudinal intervention studies investigating the effect of a vegetarian diet on the availability of these compounds currently exist.

This study aimed therefore to investigate the effect of of transiently switching omnivores onto a vegetarian diet for 6 months on muscle and plasma creatine, carnitine and carnosine homeostasis.

We hypothesized that homeostasis of creatine and carnosine would be disrupted when their dietary intake was missing. For carnitine, however, we hypothesized that homeostasis can be maintained given its slow turnover rate and its presence in some non-meat nutrients. A second aim was to investigate whether supplementation of creatine and beta-alanine (the rate-limiting precursor of carnosine synthesis), concurrently with a lacto-ovo-vegetarian diet, was able to correct for potentially emerging deficiencies.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Forty healthy female omnivores will be included in this 6-month intervention study. Exclusion criteria are smoking, chronic use of medication, athletes participating in competitions, vegetarianism or eating meat or fish less than 5 times a week. The study is scheduled over a period of 6 months and measurements will be performed 1 week prior to the intervention (0M), after 3 months (3M) and within the last week (6M). Ten women will continue their omnivorous diet throughout the entire study (controls) and the other 30 subjects will switch to a lacto-ovo-vegetarian diet for 6 months. The vegetarian group will be split in 2 groups, matched for age, weight, height and baseline carnosine concentrations in soleus and gastrocnemius medialis muscles. Fifteen of them will be supplemented with beta-alanine and creatine (Veg+Suppl) and the other 15 women will receive a placebo (Veg+Pla). A co-worker, not involved in the study design and analysis, will perform the randomisation and will prepare the containers with supplements. With regard to supplementation, the study is double-blind placebo-controlled. The lacto-ovo-vegetarian diet consists of vegetables, fruits, seeds, grains, meat substitutes, eggs and dairy products and the exclusion of meat, poultry and fish. Subjects will complete a 3 day food diary at the start and after 3 months and will receive nutritional advice by a dietician during the study to prevent deficiencies in macronutrients and micronutrients. Furthermore, vegetarian recipes will be provided by email to support the subjects in their vegetarian diet.

The supplementation protocol includes simultaneously daily oral administration of creatine monohydrate (Creapure®, AlzChem AG, Germany) and slow-release beta-alanine (Carnosyn®, Natural Alternatives International, San Marcos, USA) or a placebo (maltodextrin, Natural spices, France). The supplements are considered as safe and efficacious. The Veg+Suppl group ingests 1 g of creatine monohydrate (2 capsules of 500 mg) and 0.8 g of beta-alanine (1 Carnosyn® tablet) each day during the intervention period. The Veg+Pla group will be supplemented with an identical number of capsules and tablets of maltodextrin. All subjects are asked not to take any other supplements than those provided by the current study. Compliance will be checked by asking the subjects to return the containers and counting the pills that are left. The control group, who will remain on an omnivorous diet, will not receive any supplements.

Before (0M), after 3 (3M) and 6 months (6M), subjects will perform an incremental cycling test, a fasted venous blood sample and 24hr urine will be collected, a muscle biopsy of the vastus lateralis muscle will be taken and muscle carnosine content will be determined by 1H-MRS.

A two-way analysis of variance (ANOVA) will be used to evaluate plasma and urinary metabolite concentrations, muscle carnosine, muscle biopsy metabolite concentrations, time to exhaustion (TTE) and VO2max with 'group' (Veg+Suppl; Veg+Pla; control) as between-subject factor and 'time' (0M; 3M; 6M) as within-subject factor (SPSS statistical software, SPSS Inc, Chicago, USA). For the analysis of capillary lactate and pH, measurements before and after the incremental cycling test were included as another within factor (start; end). In case of significance, analyses were repeated for each group separately and pairwise comparisons were used to compare the different time points. Values will be presented as mean ± SD and statistical significance threshold will be set at p ≤0.05.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

14 years and older (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

Female

Description

Inclusion Criteria:

  • women

Exclusion Criteria:

  • smoking, chronic use of medication or taking supplements, athletes participating in competitions, vegetarianism or eating meat or fish less than 5 times a week

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: Triple

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
No Intervention: Control
continued their omnivorous diet throughout the entire study
Experimental: Veg+Pla
vegetarian + placebo: switch to a lacto-ovo-vegetarian diet for 6 months and are supplemented with placebo pills instead of beta-alanine and creatine
Behavioral: Vegetarian diet
Other Names:
  • lacto-ovo-vegetarian diet
Dietary supplement: Placebo
pills
Experimental: Veg+ creatine and beta-alanine
switch to a lacto-ovo-vegetarian diet for 6 months and are supplemented with 1 g of creatine monohydrate (2 capsules of 500 mg) and 0.8 g of beta-alanine (1 Carnosyn® tablet) each day
Behavioral: Vegetarian diet
Other Names:
  • lacto-ovo-vegetarian diet
Dietary supplement: creatine
1g creatine/day
Dietary supplement: Beta-alanine
0.8g beta-alanine per day

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Fasted Plasma Beta-alanine Concentration
Time Frame: 6 months
Fasted venous plasma beta-alanine concentration (precursor for carnosine) at 0, 3 and 6 months of the intervention
6 months
Gastrocnemius Carnosine Concentration
Time Frame: 6 months
Gastrocnemius carnosine concentration at 0, 3 and 6 months of the intervention
6 months
Soleus Carnosine Concentration
Time Frame: 6 months
Soleus carnosine concentration at 0, 3 and 6 months of the intervention
6 months
Plasma Creatine Concentration
Time Frame: 6 months
Plasma creatine concentration at 0, 3 and 6 months of the intervention
6 months
Plasma Creatinine Concentration
Time Frame: 6 months
Plasma creatinine at 0, 3 and 6 months of the intervention
6 months
Plasma Guanidinoacetate Concentration
Time Frame: 6 months
Plasma guanidinoacetate at 0, 3 and 6 months of the intervention
6 months
Urinary Creatinine Concentration
Time Frame: 6 months
Urinary creatinine at 0, 3 and 6 months of the intervention
6 months
Muscle Creatine Concentration
Time Frame: 3 months
Muscle total creatine concentration in vastus lateralis muscle at 0 and 3 months of the intervention
3 months
Plasma Carnitine Concentration
Time Frame: 6 months
plasma free carnitine concentration at 0, 3 and 6 months of the intervention
6 months
Plasma Acetylcarnitine Concentration
Time Frame: 6 months
plasma acetylcarnitine concentration at 0, 3 and 6 months of the intervention
6 months
Plasma Total Carnitine Concentration
Time Frame: 6 months
plasma total carnitine concentration (free + acetyl) at 0, 3 and 6 months of the intervention
6 months
Muscle Carnitine Concentration
Time Frame: 3 months
muscle free carnitine concentration in vastus lateralis muscle at 0 and 3 months of the intervention
3 months
Muscle Acetylcarnitine Concentration
Time Frame: 3 months
muscle acetylcarnitine concentration in vastus lateralis muscle at 0 and 3 months of the intervention
3 months
Muscle Total Carnitine Concentration
Time Frame: 3 months
muscle total carnitine concentration (free + acetylcarnitine) in vastus lateralis muscle at 0 and 3 months of the intervention
3 months

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Vitamin D Status
Time Frame: 6 months
Serum 25-Hydroxyvitamin D concentration at 0, 3 and 6 months of the intervention
6 months
Urinary Biomarker for Meat Intake: Pi-methyl-histidine
Time Frame: 6 months
urinary pi-methyl-histidine concentration at 0, 3 and 6 months of the intervention
6 months
Urinary Biomarker for Meat Intake: Tau-methyl-histidine
Time Frame: 6 months
urinary tau-methyl-histidine concentration at 0, 3 and 6 months of the intervention
6 months
Urinary Biomarker for Meat Intake: Anserine
Time Frame: 6 months
urinary anserine concentration at 0, 3 and 6 months of the intervention
6 months
VO2max
Time Frame: 6 months
VO2max during incremental cycling test performed at 0, 3 and 6 months
6 months
Time to Exhaustion
Time Frame: 6 months
Time to exhaustion during incremental cycling test performed at 0, 3 and 6 months
6 months
Capillary Lactate
Time Frame: 6 months
capillary lactate at the start and at the end of the incremental cycling test performed at 0, 3 and 6 months
6 months
Capillary pH
Time Frame: 6 months
capillary pH at the start and at the end of the incremental cycling test performed at 0, 3 and 6 months
6 months

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University Ghent

Investigators

Investigators

A researcher involved in a clinical study. Related terms include site principal investigator, site sub-investigator, study chair, study director, and study principal investigator.
  • Principal Investigator: Wim Derave, Professor, University Ghent

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

General Publications

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
December 1, 2012

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
June 1, 2013

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
June 1, 2013

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 15, 2017

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 20, 2017

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 21, 2017

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 28, 2019

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
October 25, 2018

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
October 1, 2018

More Information

Terms related to this study

Keywords

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • EC/2012/666

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

IPD Plan Description

individual data will not be made available to other researchers

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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