Creatine supplements are the most widely used dietary supplement or function enhancement supplement for athletes, with up to 40% of the use rate.
What are the benefits of creatine supplementation in empirical medicine? Are there any side effects or contraindications? See the article for details.
What is creatine?
Creatine is an endogenous amino acid compound molecule found in all cells of the human body and synthesized by three amino acids, arginine, glycine and methionine, in the liver, pancreas, and kidneys.
In the human body, there are two main forms of creatine, one is the phosphorylated form (60%), the other is the free form (40%), nearly 95% of creatine is stored in skeletal muscle, and the remaining 5% is found in the brain, liver, testicles and kidneys.
In addition to being available from food sources, such as meat and fish, these amino acid compounds are widely known as supplement forms since the 1990s Olympics, when athletes were commonly used to enhance athletic performance.
What are the main benefits of creatine supplementation?
The main principle of creatine supplementation is to maximize the amount of total creatine within cells.
The concentration of intracellular creatine plays an important role in real-time bioenergetic systems during high-intensity, short-term, and repetitive physical activities that rapidly deplete muscle energy stores, such as weight lifting, sprinting, or swimming.
Depending on the magnitude of the increase in intramuscular creatine, performance during high-intensity or repetitive exercise is typically improved by about 10 to 20% with additional supplementation.
In addition, endogenous creatine also plays a key role in cognitive function, including learning, memory, attention, language, and mood.
What are the proven benefits of creatine?
1. Creatine improves strength and athletic performance
The human body is designed for movement and has the ability to achieve incredible sporting achievements.
With the rapid development of sports nutrition science, nutrition is considered to be an important part of the best performance in sports.
A meta-analyses (53 double-blind, randomized, placebo-controlled trials) found that creatine supplementation improved upper extremity strength performance in the supine press and chest press training (exercise duration less than 3 minutes), particularly in the pectoralis major muscles. Note 1
A meta-analyses (60 randomized controlled trials) suggested that creatine supplementation improved lower extremity strength performance in squats and leg press training (exercise duration less than 3 minutes), particularly muscle groups in the quadriceps region. Note 2
Another meta-analyses (9 double-blind randomized experiments) showed that creatine improved performance on physical fitness tests associated with anaerobic metabolism, particularly anaerobic power. Note 3
*Conclusion: Oral creatine can help improve strength performance during high-intensity, short-term, anaerobic training
2. Creatine increases lean tissue mass and strength(for the elderly)
The loss of lean tissue (body weight consisting only of bones, organs, and muscles) and the increase in fat mass are among the most significant and consistent changes associated with age, and the proper name for this condition is sarcopenia.
Muscle loss not only increases the risk of falls and fractures, but also reduces mobility, and is associated with heart disease, respiratory disease, cognitive impairment that, if left untreated, can lead to impaired mobility, reduced quality of life, loss of independence, or the need for long-term care placement.
A meta-analysis (21 studies involving 721 adults over the age of 50) found that creatine supplementation improved lean tissue mass and increased chest and leg press strength in combination with resistance training, and increased chest and leg press strength significantly better than placebo. Note 4
*Conclusion: For older adults, creatine supplementation during resistance training is helpful in increasing lean tissue mass and improving limb strength
3. Creatine improves cognitive function
Cognitive function is the ability to think, learn, and remember, and thus forms the basis of an individual’s ability to perceive, reason, act creatively, solve problems, and intuit.
Good cognitive health, especially in old age, is necessary to remain independent and active.
A systematic review (6 randomized clinical trials with 281 healthy participants) noted that oral creatine improved short-term memory and intelligence/reasoning (particularly in populations with various stress and aging phenomena), but the effects on other cognitive domains (long-term memory, spatial memory, memory scanning, attention, executive function, response inhibition, fluency of words, reaction time, and mental fatigue) remain unclear. Note 5
*Conclusion: Oral creatine may help improve some measures of cognitive function in healthy populations, but more studies are needed to support this due to the heterogeneity of the included studies and the small sample size
4. Creatine improves bone density
Osteoporosis is the most common bone disease in humans, characterized by low bone mass, deterioration of bone tissue, and destruction of bone microstructures, which can lead to impaired bone strength and increased risk of fractures, and the high-risk groups are: Caucasians, women, and the elderly.
Fractures may lead to chronic pain, disability, especially hip fractures, a 1- to 15% increase in mortality within one year, and a 20.2-fold increased risk of future fractures.
About 20-50% of people with hip fractures require long-term home care, leading to reduced quality of life, social isolation, depression, and lack of self-esteem.
A meta-analysis (5 randomised controlled trials involving 193 men >50 years of age or postmenopausal women) found that creatine combined with resistance training did not significantly improve whole-body, hip, femoral neck, or lumbar spine bone density compared with resistance training alone (duration of intervention (12 weeks to 1 year), frequency of exercise per muscle per week (1.5 to 3 times per week)). Note 6
*Conclusion: Resistance training combined with creatine is not effective in improving bone mineral density in the short term, but due to the high risk of bias of the included studies, further validation is required for long-term trials
5. Creatine is beneficial for chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease, the sum name of the disease of chronic bronchitis and emphysema, is the most common chronic respiratory disease in the world and is very common in people over the age of 75.
Common features are limited expiratory airflow, and persistent cough is a common symptom, especially with mucus secretion, dyspnea, wheezing, chest tightness.
Important comorbidities associated with COPD include cardiovascular disease (coronary heart disease, heart failure, hypertension), diabetes, metabolic syndrome, obesity, osteoporosis, stroke, lung cancer, skeletal muscle weakness, anemia, depression, and cognitive decline.
A systematic literature review and meta-analysis (including 4 randomized controlled trials of 151 patients with COPD who received a pulmonary rehabilitation programme) noted that creatine supplementation had no significant effect on improving exercise capacity, upper and lower extremity muscle strength, or health-related quality of life. Note 7
*Conclusion: For patients with chronic obstructive pulmonary disease who are receiving a pulmonary rehabilitation program, oral creatine is not helpful for disease improvement, but limited by small sample sizes, more studies are needed for further validation
6. Creatine reduces the damage caused by sleep deprivation
Sleep deprivation is a common occurrence for modern people, especially for working women, busy at work, after work and household affairs and children to respond, a series of these invisible pressures, resulting in a decline in sleep time and quality.
Dark circles are everyone’s first impression of sleep deprivation, but the harm it brings is not simple, and it is known to cause damage to the mind, alertness, emotions and ability to deal with affairs in the short term. Part of the physiological mechanism behind it may be related to the decrease in creatine concentration in the brain.
A randomized, double-blind, placebo-controlled study of sleep deprivation found that taking creatine reduced the impairment of mood, balance, and cognitive function associated with sleep deprivation. Note 9
Are there any side effects of creatine?
Creatine has a high safety profile for most people in good health and at appropriate doses.
However, possible side effects or adverse reactions that have been reported include: stomach pain, nausea, diarrhea, muscle cramps, dizziness, dehydration, weight gain (due to muscle water retention), heat intolerance, constipation, fever, restlessness, etc. (these conditions are particularly common in excessive use).
A 21-month study that monitored 52 blood and urine biochemical indices of creatine users did not find any abnormal adverse reactions. Note 8
Safety precautions (5 contraindications to use)
1. Do not use by pregnant and lactating women (due to unknown safety)
2. Do not use for patients with bipolar disorder (may cause symptoms to worsen)
3. Do not use if the liver and kidney function is poor (may cause symptoms to worsen)
4. If you have Parkinson’s and take creatine, avoid caffeine at the same time (as studies have found that it may make the disease worse faster)
5. Do not use in combination with nephrotoxic drugs, may increase the chance of kidney damage, related common drugs are: cyclosporine, amikacin (bukacin), gentamicin, tobramycin, non-steroidal anti-inflammatory drugs: ibuprofen, indomethacin, naproxen, piroxicam etc.
What dose of creatine is used? How to soak?
For meat-eating populations (who usually consume fish and meat regularly), the creatine content in the muscles is about 60 to 80%
There are many different dosage regimens to boost reserves, the most widely used being the short-term loading dose or filling period, in which you take large amounts of creatine for a short period of time to quickly saturate your muscles, followed by a long-term maintenance dose.
The loading dose (filling period) is generally about 0.3 grams per kilogram of body weight (or 0.136 grams per pound), taking 66 kilograms as an example, 20 grams per day (divided into 4 5 grams each) for 4 to 7 days
After the loading dose, the maintenance dose is usually 0.03 grams per kilogram of body weight, taking 66 kilograms as an example, 2 to 5 grams per day to maintain the creatine content in the muscles.
If you choose not to do the loading dose, you can consume 3 to 5 grams per day, which may take 3 to 4 weeks to maximize your reserves
Avoid using too high a dose at a time (which may increase the chance of side effects or adverse reactions) and always read the product dosage recommendations