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/ Rate This Message: http://www.cryonet.org/cgi-bin/rate.cgi?msg=8686