Life
Extension:
Science
or Science Fiction?
By: National
Institute on Aging
How can people stay healthy and
independent, as they grow older?
Recently, researchers have begun to find certain chemicals in our bodies
that may someday answer these questions. As a result, some stores and
catalogs now sell products that are similar to these chemicals. However,
the advertising claims that these products can extend life are very much
exaggerated. Here are some of the chemicals being studied and what
scientists have learned about them so far.
Antioxidants. These are natural substances that may help
prevent disease. Antioxidants fight harmful molecules called oxygen free
radicals, which are created by the body as cells go about their normal
business of producing energy. Free radicals also come from smoking,
radiation, sunlight, and other factors in the environment.
Some antioxidants, such as the enzyme SOD (superoxide dismutase), are
produced in the body. Others come from food; these include vitamin C,
vitamin E, and beta carotene, which is related to vitamin A.
The body’s antioxidant defense system prevents most free-radical damage,
but not all. As people grow older, the damage may build-up. According to
one theory of aging, this build-up eventually causes cells, tissues, and
organs to break down.
There is some evidence to support
this theory. For instance, the longer an animal lives, the more
antioxidants it has in its body. Also, some studies show that antioxidants
may help prevent heart disease, some cancers, cataracts, and other health
problems that are more common as people get older.
Most experts think that the best way to get these vitamins is by eating
fruits and vegetables (five helpings a day) rather than by taking vitamin
pills. SOD pills have no effect on the body. They are broken up into
different substances during digestion. More research is needed before
specific recommendations can be made.
DNA and RNA. DNA (deoxyribonucleic acid) is the material
in every cell that holds the genes. Every day some DNA is damaged and most
of the time it is repaired. But more and more damage occurs with age, and
it may be that DNA repair, never 100 percent perfect, falls further and
further behind. If so, the damage that does not get repaired and builds up
could be one of the reasons that people age.
As a result, pills containing DNA and RNA (ribonucleic acid, which works
with DNA in the cells to make proteins) are on the market. But DNA and RNA
are like SOD tablets. When they are taken by mouth, they are broken down
into other substances and cannot get to cells or do any good.
DHEA. Short for dehydroepiandrosterone, DHEA is a hormone
that has turned back some signs of aging in animals. When given to mice,
it has boosted the immune system and helped prevent some kinds of cancer.
DHEA travels through the body in the blood in a special form, called DHEA
sulfate, which turns into DHEA when it enters a cell. Levels of DHEA
sulfate are high in younger people but tend to go down with age.
Substances labeled DHEA are being sold as a way to extend life, although
no one knows whether they are effective.
Other Hormones.
In a recent study with a small number of men, injections of growth hormone
boosted the size and strength of the men’s muscles and seemed to reverse
some signs of aging. Now, larger studies are testing growth hormone and
other hormones, such as estrogen and testosterone, to find out whether
they can prevent weakness and frailty in older people.
However, it is much too early to know whether any of these hormones will
work. There could be problems. Moreover, the side effects of hormones
could be very serious; high amounts of some hormones have been linked to
cancer.
Ten Tips for Healthy Aging
No known substance can extend life,
but the chances of staying healthy and living a long time can be improved:
Eat a balanced diet, including five
helpings of fruits and vegetables a day.
Exercise regularly (check with a
doctor before starting an exercise program).
Get regular health check-ups.
Don’t smoke (it’s never too late
to quit).
Practice safety habits at home to
prevent falls and fractures. Always wear your seatbelt in a car.
Stay in contact with family and
friends. Stay active through work, play, and community.
Avoid overexposure to the sun and the
cold.
If you drink, moderation is the key.
When you drink, let someone else drive.
Keep personal and financial records
in order to simplify budgeting and investing.
Plan long-term housing and money
needs.
Keep a positive attitude toward life.
Do things that make you happy.
The Bottom Line
Currently no treatments, drugs, or
pills are known to slow aging or extend life in humans. Check with a
doctor before buying pills or anything else that promises to slow aging,
extend life, or make a big change in the way you look or feel.
Resources
The National Institute on Aging Information Center
P.O. Box 8057
Gaithersburg, MD 20898-8057
1-800-222-2225
1-800-222-4225 (TTY)
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