Can Creatine Supplements Boost Cognitive Function?

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Creatine is a dietary supplement for enhancing muscle performance and growth, and is very popular amongst those doing resistance training. Yet this supplement may also be quietly delaying cognitive ageing and dementia through its effects on the brain. While still in its early stages, research so far suggests that creatine might improve energy availability in the brain and improve cognitive function in old age. In this review, researchers discuss the evidence for the effects of creatine on cognitive function. But before we get into their findings, we need to establish what creatine does.

What Is Creatine?

Muscle tissue uses a lot of energy. In fact, muscle tissue accounts for about 25% of the body’s energy expenditure, and that’s when you aren’t doing any exercise at all. In biological systems, ‘energy’ comes in the form of chemical bonds, specifically those in a molecule called adenosine triphosphate (ATP), the cell’s universal fuel source. ATP is manufactured within the tiny power plants called mitochondria. During exercise, muscles burn through a lot of ATP – so much that the mitochondria can’t keep up. That’s why we’ve evolved a system to shore up ATP production in times of need: creatine.

Creatine is a chemical within muscle tissue that stores ATP by proxy. ATP itself is too unstable to be stored, so the mitochondria can’t just work harder to build up a reserve of ATP while the muscles are at rest. Instead, creatine stores an essential component of the ATP molecule – phosphate – by combining with it to form phosphocreatine. After all of the ATP in the muscle is depleted, this stored phosphate can be used to rapidly generate more ATP, allowing the muscle to continue to function at full capacity for a short time. After this phosphate is depleted, cells have to rely on anaerobic respiration to produce most of the ATP the muscle will use. Anaerobic respiration doesn’t require oxygen and can sustain muscle activity for much longer, but it is inefficient and also produces lactic acid as waste, limiting how well the muscle can work. All of this makes creatine very helpful for short bursts of high-intensity exercise such as sprinting or weightlifting, but not so useful for longer duration exercise in which anaerobic respiration will play a larger overall role in sustaining energy supply. Essentially, creatine provides a pool of immediately available energy that can sustain maximal effort for around 5-8 seconds, and can be accessed irrespective of oxygen or nutrient supply.

Creatine In The Brain

So that covers the role of creatine in muscle tissue, but why does any of this matter for the brain? While the brain’s ATP demands may not spike as high those of muscle tissue (if your brain ever has to use anaerobic respiration, you are probably in deep water – perhaps literally), its energy demands are still very high and can fluctuate enough that creatine is needed as a buffer. Another reason creatine is needed in neurons (brain cells) is their size – ATP-producing mitochondria are mostly clustered in the cell body, while the projecting nerve fibres can extend very long distances to other regions of the brain or to the spinal cord. This means that ATP has to diffuse long distances to reach parts of the cell that need it. Creatine carrying phosphate (phosphocreatine) diffuses faster than ATP, essentially acting as a ‘shuttle’ that helps keep distant parts of the cell supplied.

The brain may store some creatine, but it’s still a very small amount compared to skeletal muscle, which stores around 95% of the body’s creatine. Can the amount of creatine in the brain really impact cognitive function? Well, there’s some reason to think that it might. Some inherited disorders can result in cerebral creatine deficiency, most commonly due to a defect in the protein that transports creatine into cells. People with this defect suffer from both muscle weakness and cognitive impairment, which suggests that creatine deficiency does affect the brain.

The good news is that you can’t get cerebral creatine deficiency without a genetic disorder. Creatine is obtained from food (primarily meat and fish), but even if you consume very little creatine in your diet, the body is able to synthesise creatine from amino acids (protein building blocks). The bad news is that creatine levels in the brain do appear to decline with age, which could contribute to declining cognitive function. This also means that there may be an opportunity to prevent some of this decline with creatine supplements, which finally brings us back to the human evidence on this subject.

The Evidence

For the review, researchers looked for peer-reviewed studies investigating whether there was a relationship between creatine and cognitive function in adults aged 55 and above. They excluded any studies that only involved creatine in combination with other interventions, as this would make the effects of creatine specifically on the brain impossible to isolate. For example, many studies involving creatine are looking at its effects on muscle performance during strength training, but exercise and muscle health have secondary effects on cognitive function, so such studies had to be excluded.

This left researchers with 6 studies, three of which were deemed of ‘poor’ methodological quality. Two of the studies were intervention studies in which participants were given either creatine or a placebo treatment and the effects on cognitive function were measured. The remaining studies were purely observational in nature, calculating participants’ creatine intake based on dietary habits and supplement intake and looking at whether there was a relationship with cognitive performance. Such studies are easier to run but can’t prove that creatine caused any observed changes in cognitive function (since differences in creatine intake correlates with other factors that influence cognition, most notably diet and exercise).

Across all 6 studies, there were a total of 1542 participants. 5 out of 6 studies reported a positive correlation between creatine intake and some aspect of cognitive function. Unfortunately, the study reporting no correlation was one of the intervention studies and also had the highest score for quality, and so arguably carried more weight. Among the studies reporting positive findings, cognitive changes included improvements in short and long-term memory, selective attention and processing speed. However, none of the three studies that conducted the Mini Mental State Examination (a test for global cognition and cognitive impairment) found a significant correlation between creatine intake and performance in this test.

The Take-Home Message

There is some early evidence that both higher creatine intake via diet and creatine supplementation without strength training correlates with improved cognitive function, at least in some domains. There is also a strong mechanistic foundation for how creatine would do this – by increasing energy availability to neurons. However, we need more, better quality evidence to say this for certain.

What we can say is that creatine is one of the easiest dietary supplements to recommend, regardless of whether it improves cognitive function directly or not. Many supplements suffer from the problem of having promising early evidence but from limited data, often with a lack of information about safety of long-term use. Creatine is one of the most researched and safest supplements available, is well absorbed in the gut, and has been clearly shown to support strength training. Strength training is the most effective intervention to preserve muscle function and bone density into old age, which are both extremely important contributors to longevity. It is also likely that muscle mass and strength contribute to cognitive function independently of exercise – that is to say that simply having healthier muscle may protect the brain through its effects on factors like blood sugar and inflammation.

So, the take-home message for now is that you should probably be taking creatine to support strength training. If this creatine happens to also directly improve cognitive performance, this is a bonus effect, but we still need more evidence to confirm it.