Secrets of Aging
Why do you age? Nobody knows! But scientists have a few theories.
Theory 1: Random damage
Some think senescence (the aging process) is caused by random events, like damage
to proteins or DNA, which accumulate over time. The body grows old because it fails
to repair itself.
Theory 2: Free radicals
One popular theory claims aging is caused by free radicals-chemicals produced in
cells when oxygen combines with unsaturated fats. Free radicals damage cells, destroy
DNA, and cause destructive reactions, but you can slow down these reactions by using
antioxidants found in some vegetables, citrus fruits, cereals, dairy products, meat,
fish and seafood. So eat your broccoli!
Theory 3: The pacemaker
Some think each human has a built-in pacemaker. Your organs may be genetically programmed
to deteriorate and fail at certain times in your life. Some scientists have even
looked for a "death hormone" that gradually triggers aging, but none has
been found.
So who's right?
There is evidence against all of these theories.
We know that aging is related to genetics; why else would most cats live 20 years
and most turtles live 80 years? In fact, scientists extended the lifespan of a nematode
worm by 50 percent by manipulating its genes! Even identical twins have more similar
lifespans than regular siblings do, and if people in your family tend to live long
lives, you probably will too.