N/A Completed N=40 Randomized Triple-blind Basic Science

Creatine, Carnitine and Carnosine in Vegetarians

Dietary Modification

Source: ClinicalTrials.gov NCT03194334 ↗

Enrolled (actual)

Serious AEs

0.0%

Results posted

Feb 2019

Primary outcomePrimary: Fasted Plasma Beta-alanine Concentration — 3.37; 5.19; 4.56; 3.76 µM

Summary

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.

Outcome Measures

Outcome	Result	p-value
PRIMARY Fasted Plasma Beta-alanine Concentration	3.37; 5.19; 4.56; 3.76; 5.11; 5.8	—
PRIMARY Gastrocnemius Carnosine Concentration	5.18; 5.16; 5.1; 5.58; 5.55; 6.55	—
PRIMARY Soleus Carnosine Concentration	3.91; 3.53; 3.7; 3.84; 3.36; 4.72	—
PRIMARY Plasma Creatine Concentration	35.7; 29.7; 27.3; 28.1; 15.8; 56.9	—
PRIMARY Plasma Creatinine Concentration	97.33; 79.49; 79.9; 96.62; 85.68; 78.47	—
PRIMARY Plasma Guanidinoacetate Concentration	2.23; 2.06; 1.95; 2.2; 2.05; 1.87	—
PRIMARY Urinary Creatinine Concentration	1298.62; 1235.99; 1254.65; 1258.78; 1034.3; 1279.41	—
PRIMARY Muscle Creatine Concentration	133.2; 153.5; 128.2; 142.2; 128.8; 140.7	—
PRIMARY Plasma Carnitine Concentration	30.81; 29.82; 28.39; 28.7; 26.45; 25.71	—
PRIMARY Plasma Acetylcarnitine Concentration	8.49; 7.71; 8.09; 6.82; 6.93; 6.77	—
PRIMARY Plasma Total Carnitine Concentration	41.58; 40.85; 40.24; 37.96; 36.16; 35.9	—
PRIMARY Muscle Carnitine Concentration	13.1; 12.1; 10.7; 11.5; 11.5; 9.7	—
PRIMARY Muscle Acetylcarnitine Concentration	3.3; 4.2; 3.3; 3.6; 3.5; 3.2	—
PRIMARY Muscle Total Carnitine Concentration	16.5; 16.3; 13.9; 15.5; 13.6; 12.7	—
SECONDARY Vitamin D Status	32.7; 29.1; 29.8; 24.9; 22.7; 24.6	—
SECONDARY Urinary Biomarker for Meat Intake: Pi-methyl-histidine	161.9; 167.4; 212.9; 117.8; 26.4; 28.7	—
SECONDARY Urinary Biomarker for Meat Intake: Tau-methyl-histidine	55.2; 63.1; 63.0; 74.6; 43.1; 46.1	—
SECONDARY Urinary Biomarker for Meat Intake: Anserine	15.0; 9.2; 10.7; 9.5; 5.5; 4.4	—
SECONDARY VO2max	40.4; 39.4; 36.6; 39.0; 37.8; 34.8	—
SECONDARY Time to Exhaustion	14.5; 15.1; 13.8; 14.0; 14.7; 13.6	—
SECONDARY Capillary Lactate	1.9; 2.0; 1.8; 10.7; 12.4; 10.7	—
SECONDARY Capillary pH	7.4; 7.41; 7.42; 7.28; 7.24; 7.28	—

Eligibility Criteria

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

View full record on ClinicalTrials.gov →

Data sourced from ClinicalTrials.gov (NCT03194334). Outcome figures and adverse-event rates are extracted automatically from the registry's posted results and are provided for clinician reference, not as a substitute for the primary publication. Informational only — not medical advice.