speech, or swiping through your favorite dating app, your
brain is burning through fuel at the same rate as the leg
muscles during a marathon race.^1
Our energy crisis is not from a shortage of fuel,
however. Our brains, if anything, are overfueled. For the
first time in history, there are more overweight than
underweight humans walking the Earth.^2 So what, then,
accounts for the cognitive malaise?
Punished at the Pump
By the middle of the twentieth century, petroleum-based
gasoline became the fuel used by the vast majority of cars
on the road. It is only now, decades later, that we realize our
gasoline addiction has many long-term side effects and
unintended consequences, not appreciated until potentially
irreversible havoc has been wrought on the environment
and our health.
Glucose, one of the brain’s primary forms of fuel, is in
many ways like gasoline, and it enters the blood by way of
the carbohydrates we consume. A warm sourdough roll?
Glucose. A medium baked potato? Glucose. A wedge of
highly cultivated sweet pineapple? Glucose (and fructose).
When you consume it frequently, glucose provides the main
source of energy for the brain. From this sugar, our
mitochondria generate energy at the cellular level through a
form of complex combustion involving oxygen. This
process is called aerobic metabolism, and life as we know it
would be impossible without it. But as with gasoline,