Creatine: benefits, dosage, contraindications
Scientific name(s)
2-[carbamimidoyl(methyl)amino]acetic acid.
Family or group:
Amino acids
Indications
Scoring methodology
EFSA approval.
Sports performance ✪✪✪✪✪
Creatine supplementation has become widely used by athletes and, for some, is the only effective ergogenic aid in addition to carbohydrate loading. It is used by athletes engaged in sprint disciplines (for example, the 100 m run or the 50 m swim), strength disciplines (for example, weightlifting), or high-intensity, repetitive exercises (for example, tennis, hockey, football, soccer). Studies indicate that creatine supplementation (about 20 g/day for 5 days or about 2 g/day for 30 days) results in an increase in muscle creatine and phosphocreatine concentrations of approximately 15–40%, improves anaerobic exercise capacity, and increases training volume, leading to potentially greater gains in strength, power, and muscle mass. Myocytes use creatine to produce phosphocreatine via the enzyme creatine kinase. Phosphocreatine is used to convert adenosine diphosphate (ADP) into adenosine triphosphate (ATP). It also buffers intracellular hydrogen ions associated with lactate production and muscle fatigue during exercise. Thus, creatine can increase both the force of muscle contraction (by raising ATP levels) and the duration of anaerobic exercise. European health authorities (EFSA, the European Food Safety Authority, and the European Commission) have concluded that foods and food supplements containing creatine can claim to increase physical performance during short, intense, and repeated bouts of exercise, if and only if the recommended daily dose is three grams of creatine. In addition, EFSA has recognized that a daily intake of 3 grams of creatine could strengthen the musculature of people over 55 who perform resistance exercise at least three times per week (short, intense, and repeated efforts), for example, strength training.
Posologie
Oral administration
3 - 20 g
Acute creatine supplementation and performance during a field test simulating match play in elite female soccer players
Analysis of the efficacy, safety, and regulatory status of novel forms of creatine
Creatine supplementation augments the increase in satellite cell and myonuclei number in human skeletal muscle induced by strength training
Use of creatine in the elderly and evidence for effects on cognitive function in young and old
Effect of creatine supplementation on body composition and performance: a meta-analysis
Optimizing the Benefits of Exercise on Physical Function in Older Adults
Low-dose creatine supplementation enhances fatigue resistance in the absence of weight gain
In sickness and in health: the widespread application of creatine supplementation
Neurodegenerative diseases ✪✪✪✪✪
In recent years, a considerable body of scientific evidence has shown that creatine supplementation can alleviate certain symptoms of degenerative neurological diseases and slow their progression. rnrnIndeed, a double-blind clinical trial conducted on patients with Huntington's disease who received 8 g/day of creatine for 16 weeks showed an increase in creatine concentrations in the brain and serum and a reduction in oxidative DNA damage. Another clinical study showed that taking creatine monohydrate, at 20 g/day for 5 days followed by 5 g/day for 12 weeks, in combination with resistance training, resulted in improved muscular endurance. rnrnFurthermore, neuroprotective effects have been observed in animal models but have not been proven in clinical trials. This may be due to differences in the pathophysiological processes of neurodegenerative disease in humans, as well as differences in dosage and the timing of creatine supplementation relative to disease onset.rnrnMoreover, a combination of creatine and Coenzyme Q10 may offer additional benefits in neurodegenerative diseases because they both act at the mitochondrial level and are involved in ATP production while exerting antioxidant effects.rnrnrnrnrn
Posologie
Orally
5 - 20 g
Synergies
Resistance training with creatine monohydrate improves upper-body strength in patients with Parkinson disease: a randomized trial
Health implications of creatine: can oral creatine supplementation protect against neurological and atherosclerotic disease?
Creatine in Huntington's disease is safe, tolerable, bioavailable in the brain and reduces serum 8OH2'dG
Creatine in mouse models of neurodegeneration and aging
Fibromyalgia ✪✪✪✪✪
Theoretically, creatine supplementation may reduce muscle fatigue associated with fibromyalgia and improve strength. One study showed that taking creatine monohydrate (3 g/day for 3 weeks then 5 g/day up to 8 weeks) improves fibromyalgia symptoms (measured by the Fibromyalgia Impact Questionnaire), sleep quality, and pain intensity. More recently, another double-blind study over a 16-week period showed that creatine monohydrate (20 g in four doses for 5 days, followed by 5 g/day for the remainder of the study) increases muscle phosphocreatine content and improves lower-body and trunk muscle strength compared with placebo. However, no differences were observed in cognitive function, sleep quality, or quality of life.
Posologie
Orally
3 - 20 g
Depression ✪✪✪✪✪
A potential role for the use of creatine in psychiatric disorders is beginning to be explored. Magnetic resonance spectroscopy (magnetic resonance spectroscopy sequences allow a non-invasive exploration of brain metabolism during an MRI examination) finds changes in brain creatine metabolism in a number of psychiatric disorders, including depression. A reduction in creatine metabolism has been associated with a worse disease course and prognosis. Three clinical trials with different designs have revealed a beneficial effect of combining antidepressant medications with creatine (4 to 5 g/day for 4 to 8 weeks) in people with major depressive disorder.
Posologie
Oral
4 - 5 g
8 - weeks
A randomized, double-blind placebo-controlled trial of oral creatine monohydrate augmentation for enhanced response to a selective serotonin reuptake inhibitor in women with major depressive disorder
Creatine metabolism and psychiatric disorders: Does creatine supplementation have therapeutic value?
Open-label adjunctive creatine for female adolescents with SSRI-resistant major depressive disorder: a 31-phosphorus magnetic resonance spectroscopy study
Osteoarthritis ✪✪✪✪✪
A double-blind study conducted in postmenopausal women with knee osteoarthritis showed that creatine supplementation (20 g/day for 1 week then 5 g per day for 11 weeks) combined with strengthening exercises for 3 months improved quality of life, physical function, stiffness, and lower-limb lean mass compared with placebo.
Posologie
Oral
5 - 20 g
3 - months
Rheumatoid arthritis ✪✪✪✪✪
Clinical research in adults with rheumatoid arthritis shows that creatine supplementation increases lean muscle mass, skeletal muscle creatine content, and muscle strength, but does not change disease activity and does not improve objective physical function compared with placebo. This suggests that creatine supplementation may attenuate muscle loss and may be beneficial for patients suffering from severe rheumatoid cachexia. Creatine was taken at a dose of 5 grams four times a day for 5 days followed by 3 grams per day for 12 weeks in one study, and 5 grams four times a day for 5 days followed by 0.5 gram four times a day for 16 days in another study.
Posologie
Oral
2 - 20 g
Bone health ✪✪✪✪✪
According to a double-blind, placebo-controlled study conducted in older subjects, creatine supplementation (at a dose of 0.3 g/kg for 5 days followed by 0.07 g/kg up to 12 weeks), in combination with resistance training, significantly increased bone density. Another study showed that creatine supplementation at 0.1 g/kg 3 days/week (for 10 weeks) in healthy older men undergoing resistance training reduced bone resorption by 27%.
Posologie
Oral
0.07 - 0.3 g/kg
12 - weeks
Low-dose creatine combined with protein during resistance training in older men
Conjugated linoleic acid combined with creatine monohydrate and whey protein supplementation during strength training
Timing of creatine or protein supplementation and resistance training in the elderly
Creatine monohydrate and resistance training increase bone mineral content and density in older men
Cognitive performance ✪✪✪✪✪
Some clinical studies have shown that creatine supplementation (20 g/day for 5 days followed by 5 g/day for 2 days) in healthy adults improved short-term memory and reasoning compared with placebo. In addition, supplementation with creatine ethyl ester at 5 g/day improved memory and attention.
Posologie
Oral administration
5 - 20 g
5 - days
Oral creatine monohydrate supplementation improves brain performance: a double-blind, placebo-controlled, cross-over trial.
Cognitive effects of creatine ethyl ester supplementation
Dietary supplementation of creatine monohydrate reduces the human fMRI BOLD signal
Creatine supplementation and cognitive performance in elderly individuals
The influence of creatine supplementation on the cognitive functioning of vegetarians and omnivores
Parkinson's disease ✪✪✪✪✪
Parkinson's disease is characterized by a decrease in muscle mass and strength. A double-blind study showed that taking creatine monohydrate at 20 g/day for 5 days, then 5 g/day for 12 weeks, combined with resistance training, improves muscular endurance and trunk strength. rnrnOther preliminary clinical research shows that taking creatine at a dose of 5 grams twice daily for 12 to 18 months reduces the rate of disease progression compared with placebo in patients who are not yet on conventional treatment. rnrnOther preliminary clinical research in patients with more advanced Parkinson's disease who are already on conventional treatment has shown that taking creatine does not decrease disease progression. However, patients who received creatine required smaller increases in dopaminergic medications compared with placebo. rnrn
Posologie
Oral
5 - 20 g
Fatigue ✪✪✪✪✪
A double-blind study in healthy subjects showed that taking creatine at 8 g/day for 5 days reduces mental fatigue compared with placebo. rnrn
Posologie
Oral
8 g
5 days
Muscular dystrophy ✪✪✪✪✪
Most research shows that taking creatine while participating in a resistance training program can increase upper and/or lower body muscle strength in older adults. rnrnA meta-analysis of studies conducted in adults aged 50 and older participating in resistance training programs shows that creatine supplementation improves chest press strength with a moderate effect size but does not improve leg press strength compared with placebo. Similarly, another meta-analysis of adults aged 45 and older participating in resistance training programs shows that creatine supplementation increases bench press strength by 1.74 kg and leg press strength by 3.25 kg compared with placebo, with no effect on measures of knee extension or biceps. rnrnMost research also suggests that creatine improves total muscle mass in older adults, although conflicting evidence exists. Some studies show that taking creatine while participating in a resistance training program appears to increase muscle mass in older adults. Meta-analyses of studies in middle-aged and older adults show that creatine supplementation combined with resistance training appears to increase total body mass by 1 kg and lean body mass by 0.9 to 1.3 kg compared with placebo. However, a meta-analysis of studies limited to older women shows no effect of creatine on muscle mass. Likewise, in healthy men aged 49 to 69 years, a small clinical trial shows that taking creatine monohydrate at 0.05 g/kg twice daily, while following supervised resistance training three days per week for one year, does not alter body composition compared with placebo.
Posologie
By mouth
3 g
Efficacy of Creatine Supplementation Combined with Resistance Training on Muscle Strength and Muscle Mass in Older Females: A Systematic Review and Meta-Analysis
Creatine supplementation and aging musculoskeletal health
Effects of high-velocity resistance training and creatine supplementation in untrained healthy aging males
Meta-Analysis Examining the Importance of Creatine Ingestion Strategies on Lean Tissue Mass and Strength in Older Adults
Effect of creatine supplementation and drop-set resistance training in untrained aging adults
Type 2 diabetes ✪✪✪✪✪
Preliminary clinical studies show a reduction in postprandial blood glucose in people with recent type 2 diabetes who take 3 to 6 grams of creatine orally per day for 5 days. The effects of treatment beyond 5 days in diabetic patients are not known. However, taking 10 grams of creatine per day for 3 months appears to improve glucose tolerance in healthy sedentary men.
Posologie
By mouth
3 - 6 g
5 - days
Effects of creatine supplementation on glucose tolerance and insulin sensitivity in sedentary healthy males undergoing aerobic training
Comparison of antihyperglycemic effects of creatine and metformin in type II diabetic patients
Properties
Bioenergetic
In skeletal muscle tissue, endogenous creatine is used for the production of phosphocreatine, an important high-energy phosphate form. Phosphocreatine breaks down into phosphate and creatine during high-intensity exercise lasting 15 to 30 seconds, in a reaction catalyzed by creatine kinase. During this process, energy is released and used to regenerate ATP, the primary energy source. Creatine is involved in an energy transport system, transferring energy from the mitochondria to the cytosol. rnrn
Usages associés
Musculoskeletal effects
Oral creatine supplementation increases phosphocreatine levels in muscles. The increase in creatine and phosphocreatine stores leads to faster ATP regeneration, which provides more immediately available energy for muscles. This is particularly important during high-intensity physical activity where rapid energy production is required. rnrnAn increase in muscle creatine may also buffer lactic acid produced during exercise, thereby delaying muscle fatigue and soreness.rnrnOn the other hand, some preliminary research suggests that creatine could increase the activity of muscle precursor cells, thereby causing muscle hypertrophy. rnrnHowever, most clinical studies have shown that the main cause of the muscle gains induced by creatine is an increase in cellular water retention. rnrn
Usages associés
Neurological
Creatine supplementation has shown neuroprotective effects in several animal models of neurological diseases, such as Huntington's disease, Parkinson's disease, and amyotrophic lateral sclerosis. Several possible mechanisms have been proposed to explain the neuroprotection. One theory suggests that creatine exerts antioxidant activity and mitochondrial-stabilizing effects, two mechanisms beneficial in neurodegenerative diseases, which are characterized by mitochondrial dysfunction and oxidative damage. Other protective actions suggested by in vitro and in vivo studies include attenuation of energy depletion, reduction of ischemia-induced damage, apoptosis, and excitotoxicity in brain tissue.
Usages associés
Antidepressant
An antidepressant effect has been demonstrated in vivo using several different animal models. Creatine appears to interact with several neurotransmitter receptors, including dopamine (D1 and D2), serotonin, and N-methyl-D-aspartate. This effect has only been observed in women.
Usages associés
Antioxidant
Preliminary clinical research shows that creatine may reduce oxidative stress. Other clinical studies show that urinary excretion of malondialdehyde and 8-hydroxy-2-deoxyguanosine (markers of oxidative stress) is significantly increased with creatine, which could suggest a reduction in oxidative DNA damage and lipid peroxidation.
Anticancer
There is conflicting evidence regarding the association between creatine intake and cancer. Some research shows that creatine and its analogues, such as cyclocreatine, inhibit tumor growth. Indeed, creatine may alter energy production via the creatine kinase system, which appears to play a role in the control of certain tumor types such as breast tumors and neuroblastomas. On the other hand, cyclocreatine, a creatine analogue, has been shown to be effective when added to standard anticancer agents, and has led to a delay in tumor growth in lung cancer cells greater than that achieved with anticancer drugs alone.rnrn
Hypoglycemic
The exact mechanisms of action of creatine on blood glucose regulation are not yet clear. However, it appears to modulate the expression of proteins and genes involved in insulin sensitivity and glycemic control. These include the AMPK-alpha protein, which increases the translocation of GLUT-4 (glucose transporter 4, whose essential role is the transport of glucose from the plasma to adipose tissue and muscle). rnrnIn vitro and in vivo results also suggest the possibility that creatine increases insulin release. rnrn
Usages associés
Bone density
In vitro, creatine stimulates osteoblast differentiation. In humans, research has shown that creatine reduces markers of bone resorption. However, most clinical research suggests that creatine does not improve bone density with aging. rnrn
Usages associés
Cognitive function
Creatine supplementation increases brain creatine and phosphocreatine levels and improves cognitive performance. rnrn
Usages associés
Safe dosage
Adults aged 18 years and older: 2 g - 20 g
There are two common dosing regimens : Loading regimen : - Fast loading: a loading dose of 5 g is taken four times a day for 5 to 7 days, followed by a maintenance dose of 2 to 10 g per day for 1 week to 6 months. A second cycle will be started again after a 4-week break. - Slower loading: a similar effect can be achieved with a daily dose of 3 g for 28 days. Simultaneous ingestion of carbohydrates (50 to 100 g) may improve creatine absorption. Once muscles are saturated, it takes about 4 weeks to return to baseline levels. No-loading regimen : A daily dose of 3 g. In practice, creatine is often taken with simple carbohydrates, such as glucose or fruit juices, in order to increase creatine accumulation in muscle.
Plantes ou autres actifs
Creatine: low interaction
Theoretically, concomitant use may increase the risk of serious adverse effects and reduce the beneficial effects of creatine.
Precautions
Pregnant women: avoid
Avoid use due to lack of reliable and sufficient information.
Breastfeeding women: avoid
Avoid use due to lack of reliable and sufficient information.
Contraindications
Renal insufficiency: contraindicated
High-dose creatine use is contraindicated in people with renal insufficiency.
