What does creatine do in your body besides building muscle?
Creatine does more in the brain than in the muscles: it buffers energy and protects the brain against stress such as sleep deprivation. For healthy people, however, the effect on cognitive ability is small and most visible under pressure, not at rest.
Creatine acts as an energy buffer in the brain: it helps brain cells produce energy quickly, even when little oxygen is available. This is the best-supported mechanism and the foundation for the other brain effects that researchers are mapping.
After 7 days of creatine supplementation, creatine levels in the brain rise by an average of 9.2%. The brain absorbs creatine less readily than muscles do, which means you probably need to supplement more, or for longer, than you would for muscle building. The optimal dose is not yet known.
That higher creatine level in the brain appears to be most helpful when the brain is under pressure. After 24 hours of sleep deprivation, attention, reaction time, balance and mood declined less sharply in people who had taken creatine. Attention loss caused by oxygen deprivation (at 10% oxygen for 90 minutes) was also restored. In people who are well rested and sleeping adequately, the effect on cognitive performance is far less clear.
In people who from birth cannot produce creatine properly due to a rare metabolic disorder, supplementation works unequivocally: brain function and mental development improve demonstrably. This is the only application in humans for which the evidence is truly strong.
In animal studies, creatine protects brain cells in diseases such as Parkinson's and Huntington's, but most clinical studies in humans have not been able to confirm this. There is also a theory that creatine lowers a particular blood marker associated with a higher risk of cardiovascular disease, but this has not yet been tested in large human studies. In addition, there are early indications of recovery after mild brain injury and of a direct antioxidant effect, but that research in humans is still very limited.
This answer draws on a series of studies in humans and animals, supplemented by cell and laboratory research. The evidence for energy buffering in brain cells and for use in congenital creatine deficiency is well supported. The evidence for cognitive protection under stress is reasonable, but comes largely from smaller studies. The evidence for neuroprotection in Parkinson's and Huntington's disease is disappointing: animal models are positive, but most clinical studies in humans provide no confirmation. The homocysteine hypothesis is so far supported only mechanistically, without large human studies.
How much curcumin should you take per day?
There is no fixed 'correct dose' of curcumin: for joint pain, less than 1000 mg per day works just as well as more, but for other uses this varies. Always combine curcumin with piperine or another formulation with better absorption, otherwise barely anything is demonstrably present in your blood.
Does creatine speed up muscle recovery?
Creatine (3 to 5 grams per day) can probably speed up muscle recovery after intense training and improve strength and muscle mass, but for the recovery effect specifically the research findings are not fully consistent.
Does creatine also help ordinary people, not just athletes?
Creatine is not just for athletes. Combined with strength training, it helps older adults gain more muscle strength, and probably also supports better memory.