energy replenishment.
But creatine isn’t just for powering through heavy gym
workouts. It’s a necessity in the brain, acting as a high-
energy buffer to help rapidly recycle ATP. While ATP use
holds stable during mental exertion, creatine levels drop in
support of the energetic needs of the brain, and higher levels
of brain creatine are correlated with better memory
performance.^13
Because they don’t eat red meat or fish, vegetarians and
vegans lack the main sources of dietary creatine, and as a
result they have lower levels of it in their blood than
omnivores.^14 (Though the body does create its own creatine,
doing so is a stress on the system—one that can raise levels
of an amino acid called homocysteine, which is a risk
marker for heart disease and Alzheimer’s.)^15 When
vegetarians were given supplemental creatine (20 grams per
day for five days), their cognitive function improved.^16 This
was replicated in another study, where supplementation of
only 5 grams of creatine per day for six weeks enhanced
working memory and processing speed and reduced mental
fatigue in vegetarians. According to the researchers, these
findings underlined a “dynamic and significant role of brain
energy capacity in influencing brain performance.”
In these studies, young, healthy omnivores didn’t
experience a significant cognitive boost, but vegetarians did.
Why? The brain may have a saturation point beyond which
supplementing with additional creatine is futile, and by
simply eating meat a person reaches this point. On the other
hand, for those who do not consume much red meat or fish,