X-Message-Number: 8686
Date: Fri Oct 17 04:25:28 1997  PST
Subject: Fwd: Fountain of youth still a ways off, research shows
From:  (Edgar W Swank)

01:12 PM ET 10/16/97

Fountain of youth still a ways off, research shows


   By Maggie Fox, Health and Science Correspondent
   WASHINGTON6 (Reuters) - Any hope of a fountain of youth to
stop people from getting older is a long way off, with science
just beginning to understand the complex genetic, physical and
hormonal causes of aging, experts said Thursday.
   But experts reviewing aging research in this week's issue of
the journal Science said there were interesting targets for
study, including genes involved in Alzheimer's disease, the
hormone DHEA and the role of exercise in keeping people young.
   Steven Lamberts and colleagues at Erasmus University in the
Netherlands said the controversial hormone DHEA -- sold in
health food stores as an elixir of youth -- was worth further
study.
  They noted that levels of DHEA -- a precursor of ``male''
hormones in both men and women -- were much lower in older
people. One study in adults showed taking DHEA tablets ``induced
a remarkable increase in perceived physical and physiological
well-being in both sexes without having an effect on libido.''
  Other studies on rats showed giving them DHEA could prevent
obesity and diabetes. But they said much more study was needed.
  Other experts are looking at genetic effects on aging.
  Caleb Finch of the Andrus Gerontology Center at the
University of Southern California and Rudolph Tanzi of
Massachusetts General Hospital in Charlestown said genes were
only responsible for about 35 percent of the variability of
life-span.
  Even in identical twins outside factors are responsible for
65 percent of the differences in age at death, they said.
''An instructive example is the ten-fold difference in lifespans
of female worker bees, which have rapid senescence (aging) and
lifespans of months, whereas queens of the same genotype show
much slower senescence during lifespans of many active years of
egg production,'' they wrote.
  The difference -- what the bees were fed as juveniles.
  They said it was conceivable that genetic engineering
experiments could transfer genes from one species to another to
alter lifespan. ``However, it seems unlikely that a few genes
determine the 25-fold difference in lifespans between rodents
and humans,'' they wrote.
  One interesting genetic candidate was the apolipoprotein
(apoE) gene, mutations of which are linked with Alzheimer's
dementia. One version of this gene does seem to be linked with
long life, although many more studies are needed, Finch and
Tanzi wrote.
  Worm studies also pointed to the clock gene, known as clk.
Nematodes with a certain mutation live up to five times longer.
  For those who do not want to wait, Lamberts's team said
exercise can be key to preventing the frailty that aging brings.
  ``Loss of muscle strength is an important factor in the
process of frailty,'' they wrote in their review of published
studies.
  One study in a home for the elderly showed a sedentary
lifestyle greatly contributed to this. ``Supervised resistance
exercise training doubled muscle strength and significantly
increased gait velocity and stair-climbing power,'' they wrote.
  The three-times a week exercise program was not difficult.
''This demonstrates that frailty in the elderly is not an
irreversible effect of aging and disease and can be reduced and
perhaps even prevented,'' they concluded.

Edgar W. Swank   <>
President - American Cryonics Society
http://www.jps.net/cryonics/

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