Today, grow old with me. The University of
Houston's College of Engineering presents this
series about the machines that make our
civilization run, and the people whose ingenuity
Aging is, without doubt, a
great mystery of the human condition. We all watch
ourselves age with mixed feelings. Sometimes we
watch with horror, sometimes with resignation.
Sometimes the luckier among us age with a peculiar
sense of fulfillment.
Not all living things age. Queen bees don't age.
The worker bees simply kill them when they stop
being fertile. Rockfish and some pine trees don't
age. They last until the erratic forces of nature
kill them. If we didn't age, those forces would
catch up with half of us by the age of about 600
years. That seems like rather more life than any of
us would really want.
In other species, old age arrives all at once. At a
point in the life of the Pacific salmon, his body
releases a rush of hormones called glutocorticoids.
They put a stop to normal body maintenance
functions. A healthy Pacific salmon dies of old age
Human aging is far less systematic than that. Our
systems shut down in different ways and at
different rates. One person becomes cancer prone.
Muscle tone deteriorates in another. One
70-year-old is still youthful. Another is old, old,
Some aging diseases result from processes that help
us earlier in life. Sickle cell anemia infects so
many Africans because, in the short term, sickle
cells protect them from malaria. Huntington's
disease attacks us in old age. But it seems to
assure its own survival by increasing its victims'
sex drive when they're younger.
The surest and simplest means for delaying old age
is to eat less. If we cut our calorie intake by 30
percent, we live longer. Unless we're very thin,
we're most under the assault of aging when we're
The reason for that isn't very dramatic. Most foods
pump a lot of junk into our system. If we eat less,
we simply accrue less poison.
Yet, in the end, I wonder if we'd really want to
end our life like the rockfish -- in the full flush
of youth. I like what Shakespeare said about aging:
Shakespeare says the reward of aging is
accrued accomplishment. It's the knowledge that our
mind has served us all. And that, of course, is a
legacy we can still add to -- even when we no longer
run the 440 in less than a minute.
Fear no more the heat o' the sun,
Nor the furious winter's rages;
Thou thy worldly task hast done,
Home thou art and ta'en thy wages.
Golden lads and girls all must,
As chimney-sweepers, come to dust.
I'm John Lienhard, at the University of Houston,
where we're interested in the way inventive minds