undereating and living long

(speculation)

In the mitochondria of each cell, electrons from food are passed down the electron transport chain and onto oxygen molecules. Each oxygen molecule accepts four electrons, and binds with four hydrogen ions to become two molecules of water.

An oxygen molecule with an extra electron, however, is highly reactive and, if it escapes from the last component of the electron transport chain before becoming water, it causes damage in the cell. Most notably these "free radicals" react with cell membranes and DNA. Mitochondrial DNA, unlike nuclear DNA, does not generate repair proteins, and accumulates more damage. Free radical damage is considered one of the most important components of aging.

We produce and take "antioxidants" to neutralize free radicals before they cause too much damage. Ingesting antioxidants like vitamins C and E, however, seems not to increase (fly and rat) maximum lifespan significantly. (Perhaps because these vitamins do not get through the mitochondrial membrane.) Nor does exercise nor nutrional supplement.

Apparently the best way - the only documented way - to extend maximum lifespan is simply to oxidize less, which means eat less. Rather than repairing damage done or neutralizing the free radicals before they do more damage, produce fewer of them along the electron transport chain. Starved fruit flies and rats have a maximum lifespan one-third longer than well-fed fruit flies and rats. And people in Okinawa, who eat 70% the calories of the rest of the Japanese people, live longer than any regional group in the world. To meet people over 100, best to be in Okinawa.

While United Statesians immediately dismiss the unpleasantness of a starvation lifestyle and direct research toward repairing the damage done by overeating, I recall a friend from Japan telling me that Okinawans are well liked for their sense of humor.