How Not to Age: The Scientific Approach to Getting Healthier as You Get Older

by Michael Greger

For an organism to reach reproductive age as soon as possible, it certainly makes sense to plow full steam ahead, but there are times one has to slow down out of necessity. When we were evolving, we didn’t have the luxury of Uber Eats and Instacart. Periodic famine was the norm. Those who didn’t slow their roll (in terms of cellular growth) during times of scarcity might not live long enough to pass along their genes. That’s why we evolved a braking mechanism triggered by caloric restriction. Remember AMPK, our fuel gauge enzyme? When our tank is drained, AMPK switches us to energy conservation mode, in part by shutting down mTOR via two separate mechanisms to ensure we don’t continue spending wildly while we have pennies in the bank. AMPK and mTOR can be thought of as the yin and yang of nutrient sensing and growth control.1365 One goes up as the other goes down, based on nutrient availability.