039: Creatine: Far More Than a Performance Enhancer
Mastering Nutrition Episode 39
Originally published December 21, 2017.
Creatine, best known for its ability to build muscle and enhance athletic performance, is also critical for fertility, digestion, mental health, protecting your hearing, and keeping your skin vibrant and youthful.
In this episode, Alex Leaf of Examine.Com and I discuss everything you need to know about creatine. I focus on the basic science of what it does in the body, and Alex takes the lead in discussing the practicalities of supplementation.
0:01:47 Cliff Notes
0:06:58 Symptoms of rare creatine biosynthesis disorders: global developmental delay, intellectual disabilities, hyperactivity, autistic behavior, and gastrointestinal defects
0:09:11 Creatine’s role in skeletal muscle as a buffer of the ATP supply
0:14:50 Creatine increases muscular contractile power by reducing ionic strength.
0:16:50 Creatine acts as a pH buffer.
0:19:57 Creatine is constantly recycling ATP, even at rest, but during intense exercise, creatine is used up faster than it can be recycled.
0:22:52 The creatine kinase system is especially important in cells and tissues that have 1) fluctuating energy demands, 2) high energy demands, or 3) long, polarized structures.
0:26:17 Creatine’s role in cells with high energy demands: gastric acid secretion in the stomach, nutrient absorption in the intestines, maintenance of intestinal villi
0:29:16 Creatine’s role in cells that are long and polarized: sperm, photoreceptors of the retina, hair cells in the inner ear, and skin (keratinocytes, hair follicles, and sebaceous glands)
0:33:46 Creatine synthesis is dependent on methylation, glycine, and arginine; creatine supplementation can cut the demand for methylation almost in half.
0:37:04 We have about 120 grams of creatine in our body and lose 2-3 grams per day via spontaneous degradation to creatinine.
0:38:36 Creatine supplementation is a strategy to help with methylation problems.
0:40:25 Alex Leaf discusses the practicalities of creatine supplementation; for dosing, 3-5 grams per day on a consistent basis.
0:43:04 Some people (about 20-30% of the population) are non-responders to creatine.
0:44:37 The best form of creatine to take is monohydrate; there is no evidence for the superiority of any other form, and some are inferior.
0:49:54 Timing of creatine supplementation
0:55:25 Why it doesn’t make sense to cycle creatine
0:59:00 Creatine may increase DHT, which might worsen hair loss if you have male-pattern baldness, but there is no direct evidence of this.
1:02:26 Rare anecdotal reports of insomnia from creatine supplementation; this is likely a temporary effect of cutting the methylation demand in half.
1:06:42 Creatine will not damage your kidneys; cystatin C as an alternative marker of kidney function.
1:11:54 Creatine causes weight gain by drawing more water into muscle tissue.
1:13:46 Wrapping up
Creatine Supplement Recommendations
I recommend Optimized Nutrition micronized creatine powder. If you buy a single bottle, it is available for Amazon Prime free one-day shipping, and costs $13.60 per bottle, which is 2.3 cents per gram or 11.5 cents per day when taken at 5 grams per day. You can save 5% if you subscribe to it, 15% if you subscribe to at least four other items, and 20% if you also pay with an Amazon store card.
If you expect to take creatine while traveling, I recommend getting Optimized Nutrition creatine caps. Carrying around capsules is a lot easier than little baggies of powder. This raises the price to about 14 cents per day but the convenience may well be worth it.
Creatine in Foods: The Database
This is the only database of the creatine content of foods on the internet. Check it out here:
Creatine in Foods: The Database
Lab Tests Related to Creatine
If you are supplementing with creatine, you will likely have at least a moderate increase in your serum creatinine. Creatinine is a breakdown product of creatine and its serum level is usually used to estimate the rate at which your kidneys are working. This is called the glomerular filtration rate (GFR). If your creatinine rises in response to creatine supplementation, it could potentially give a false signal that your kidneys are working less efficiently. Quest Diagnostics offers an estimated GFR based on cystatin C, which should be independent of creatine supplementation and avoid this problem.
In theory, you can test your serum creatine (Quest, LabCorp) to see if your endogenous synthesis is adequate. However, these tests are designed to look at diseases that can elevate creatine levels and the reference range would be difficult to interpret. Similarly, Quest offers a creatine biosynthesis disorders panel that is actually designed to look for inadequate synthesis, but the reference range is designed to separate people with severe genetic disorders from everyone else, so will be too broad to be used for moderately decreased creatine synthesis.
A plasma amino acid analysis (my preference: Genova ION Profile + 40 amino acids; also: LabCorp, Quest, Great Plains, and the NutrEval) may reveal low glycine or arginine levels, which could compromise creatine synthesis.
Homocysteine (LabCorp, Quest), when elevated, suggests deficient methylation, which also would compromise creatine synthesis. Homocysteine is included on the Genova ION and Great Plains amino acid profiles listed above but not the others.
For further methylation-related testing, see the lab tests listed in Living With MTHFR (under show notes).
Creatine Links and Research
Walliman, et al. The creatine kinase system and pleiotropic effects of creatine. 2011.
Brosnan, et al. The metabolic burden of creatine synthesis. 2011
Brosnan and Brosnan. The role of dietary creatine. 2016.
Gualano et al. Effect of short-term high-dose creatine supplementation on measured GFR in a young man with a single kidney. 2010.
Gualano et al. In sickness and in health: the widespread application of creatine supplementation. 2012.
Rackayova, et al. Creatine in the central nervous system: From magnetic resonance spectroscopy to creatine deficiencies. 2017.
Jagim, et al. A buffered form of creatine does not promote greater changes in muscle creatine content, body composition, or training adaptations than creatine monohydrate. 2012.
van der Merwe, et al. Three weeks of creatine monohydrate supplementation affects dihydrotestosterone to testosterone ratio in college-aged rugby players. 2009.
Steenge, et al. Stimulatory effect of insulin on creatine accumulation in human skeletal muscle. 1998.
Green et al. Carbohydrate ingestion augments skeletal muscle creatine accumulation during creatine supplementation in humans. 1996.
Syrotuik and Bell. Acute creatine monohydrate supplementation: a descriptive physiological profile of responders vs. nonresponders. 2004.
Gill et al. Creatine serum is not as effective as creatine powder for improving cycle sprint performance in competitive male team-sport athletes. 2004.
Spillane. The effects of creatine ethyl ester supplementation combined with heavy resistance training on body composition, muscle performance, and serum and muscle creatine levels. 2009.
A patent on creatine nitrate.
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