My dad and I used to watch the Indianapolis 500 Race each Memorial day. Three and a half hours and 200 laps of excitement. It always happened on Sunday, so we ate steak and potatos during the race. Why do I bring this up on my blog? It turns out race cars can teach us about aging.
The Indycar league cultivates competitive cars through strict engine and chassis requirements. The cars must have specific size, weight, and features. All engines are manufactured to be the same and randomly assigned. A team can posess only one unmodified engine at a time and is only allowed four fresh engines for the entire racing season. That means pratice and qualifying runs for the cars have to be brief and the drivers have to avoid mechanical failures from pushing the cars too hard. The teams have to understand the Rate-of-Living Theory for engines.
In humans, the Rate-of-Living Theory states aging is from wear and tear. The harder your body works the quicker you age. A race car traveling hundreds of miles an hour for hours at a time is going to wear out more quickly than a car driven on a short commute each day.
In animals, scientists have studied the concept by raising houseflies in cages smaller than teacups. In normal lab conditions houseflies live one month. When their flight is severely limited, they live more than twice as long. Caloric restriction is a therapy that has shown similar life extension in yeast, worms, rats, and monkeys. Researchers slash the amount of calories in the diets of these animals, while continuing to give them their necessary nutrients, and they see 40%-60% increases in their lifespans.
The increase may be due in part to hunger making these animals less active, but it also appears to change their metabolisms, the engines that create their energy. Caloric restriction seems to cause cells to regulate energy and respond to the environment differently as they age. One primate study found that no monkeys on caloric restriction showed signs of diabetes until 23 years into the 25 year trial, while many of the monkeys allowed to eat as much as they wanted started to show signs of diabetes and other disorders as early as six months into the study. Diabetes is one of the leading causes of death and disability in the US, managing it and heart disease, could reduce the ravages of aging and drawn out death for thousands.
What do we learn from the Rate-of-Living Theory? There seems to be a link between metabolism and aging, especially where intake of calories is involved. Yet most people would not decrease their caloric intake 30%, even for an increased lifespan. Many would rather drive their metabolisms hard and fast by eating what they want, but there is evidence that even a 10% decrease in calories could increase a person’s lifespan. If we find the mechanism behind caloric restriction, there may even be an easy way out, a pill or a procedure that would mimic caloric restriction without the diet. Until then, make it a tradition to eat vegetables instead of steak while watching the Indy 500.