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Dietary GAA and global DNA methylation

Guanidinoacetic acid (GAA) is an experimental dietary additive and has been reported to induce methyl depletion when provided by the diet. However, no study evaluated whether supplemental GAA affects DNA methylation, a critical epigenetic process for genome regulation. In this open-label, repeated-measure interventional trial, we evaluated the impact of 12 weeks of GAA supplementation on […]

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Human skeletal muscle contains no detectable GAA

We analyzed data from previously completed trials to determine the effects of supplemental guanidinoacetic acid (GAA) on markers of muscle bioenergetics in healthy men using 1.5 T magnetic resonance spectroscopy. No detectable GAA (<0.1 μmol/L) was found in the vastus medialis muscle at baseline nor at follow-up. This implies deficient GAA availability in the human […]

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GAA loading, cardiometabolic risk and inflammation

In this open-label trial, we examined the effects of the 10-week supplementation with 3 grams per day of GAA on biomarkers of cardiometabolic risk and inflammation in 20 apparently healthy volunteers (10 men and 10 women; age 22.0 ± 2.3 years). GAA had no significant effects on serum hsCRP, HDL cholesterol, insulin, and triglycerides. Clinical […]

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Dietary GAA increases brain creatine levels

Guanidinoacetic acid (GAA) is an experimental dietary additive that might act as a creatine source in tissues with high-energy requirements. In this case study, we evaluated brain levels of creatine in white matter, gray matter, cerebellum, and thalamus during 8 wk oral GAA administration in five healthy men and monitored the prevalence and severity of […]

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GAA increases skeletal muscle creatine in men

Guanidinoacetic acid (GAA; also known as glycocyamine,betacyamine, or guanidinoacetate) is an experimental dietaryadditive that enhances serum creatine bioavailability and affectsblood-derived metabolic markers of methylation in humans. Because creatine is an important compound in cellular bioener-getics, consumption of GAA has been recognized as an effec-tive investigational intervention to facilitate creatine-mediatedenergy provision in health and disease. At […]

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GAA vs. creatine for brain and muscle creatine levels

In this randomized, double-blind, crossover trial, we evaluated whether 4-week supplementation with guanidinoacetic acid (GAA) is superior to creatine in facilitating creatine levels in healthy men (n = 5). GAA (3.0 g/day) resulted in a more powerful rise (up to 16.2%) in tissue creatine levels in vastus medialis muscle, middle-cerebellar peduncle, and paracentral grey matter, […]

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Supplementing GAA in chronic fatigue syndrome

A variety of dietary interventions has been used in the management of chronic fatigue syndrome (CFS), yet no therapeutic modality has demonstrated conclusive positive results in terms of effectiveness. The main aim of this study was to evaluate the effects of orally administered guanidinoacetic acid (GAA) on multidimensional fatigue inventory (MFI), musculoskeletal soreness, health-related quality […]

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6-wk GAA loading improves muscular performance

Guanidinoacetic acid (GAA), a natural precursor of creatine, is a new promising dietary supplement, yet its performance-enhancing effect, if any, has yet to be established. The purpose of this pilot study was to evaluate the effects of supplemental GAA on muscle strength, anaerobic performance, and aerobic performance in healthy men and women. The study enrolled […]

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Oxidant-antioxidant capacity of dietary GAA

Guanidinoacetic acid (GAA) is an experimental nutritional additive under the functional group amino acids and derivatives, yet its use in human nutrition is hindered by limited data on GAA safety. In this double blind, placebo-controlled pilot study, we evaluated the effects of dietary GAA (3 g/day) administered for 2 weeks on the oxidant-antioxidant system in […]

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Single-dose GAA exhibits dose-dependent PKs

Guanidinoacetic acid (GAA), the natural precursor of creatine, has potential as a dietary supplement for human nutrition, yet no data are available regarding its dose-dependent pharmacokinetic (PK) behavior. We hypothesized that a single dose of orally administered GAA exhibited dose-dependent PK behavior in healthy volunteers. Forty-eight young adults were enrolled in a randomized, placebo-controlled, double-blind, […]

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