New Drugs Make Worm Live Twice as Long
Sept. 6, 2000 -- You want to live forever — or at least a whole lot longer? A tiny worm currently being investigated by a British and American team of scientists could hold the clue to a longer and healthier life.
The microscopic nematode worm, Caenorhabditis elegans, normally lives only 20 days, after which it usually curls up and dies.
But now scientists, using some very simple drugs, have managed to double its life span. And, with a little help from flies and mice, and possibly some human guinea pigs, they are hot on the trail of what they think could be the “elixir of life.”
The results of the experiments, published in the latest edition of Science magazine, show that the research team has managed to delay the aging process and postpone a natural death in this particular worm.
But will it work for humans?
‘Aging Is a Condition’
“These results are the first real indication we have had that aging is a condition that can be treated through appropriate drug therapy,” says team member Simon Melov of the Buck Institute for Age Research in California. “Further studies on higher organisms in the near future will allow us to answer whether or not we have to reconsider aging as an inevitability.”
The scientists used two simple drugs to mimic the body’s natural way of reducing the damage caused by “oxygen free radicals” — chemically reactive forms of oxygen that are a normal by-product of animal metabolism. These free radicals attack healthy tissues and DNA if allowed to roam around too freely and too long.
The drugs they have used are synthetic version of two natural enzymes, superoxide dismutase and catalase. Their job in the body is to attack those marauding free radicals and break them down into harmless water and oxygen.
Worms that developed in the presence of these drugs lived between 30 and 120 percent longer than those who lacked the drugs. On a human scale, that opens up the prospect of a “normal” life span of 120 years, and possibly well beyond.
“We were amazed by what we were seeing down the microscope as these experiments progressed,” says another team member, Gordon Lithgow, a senior lecturer at the University of Manchester in England. “As the untreated worms began to die, the drug-treated worms were swimming around, full of life.”
Every time the experiment was repeated the results were the same. The team realized it was on to “something pretty significant.” But Lithgow also warns “it will take a lot more work to find out exactly what is going on here.”
“It’s a ridiculously simple idea that aging is due to oxidative stress but all the data is pointing to it,” he adds.
Human Trials Beginning Soon?
The research is backed by other work on fruit flies and mice. Fruit flies carrying mutations that boost their production of antioxidants can live up to 75 days compared with an average life of 45 days. Mice with a similar genetic mutation live 30 percent longer.
Human trials could begin very soon. The patients involved are those suffering from radiation burns, which generate free radicals, which in turn lead to oxidative stress.
“These drugs have in fact been developed to attack the diseases that are due to oxidative stress,” Lithgow says. “There are diseases associated with old age, such as Parkinson’s and Alzheimer’s, where oxidative stress is thought to be a factor.”
Some dieters may already be on the right track. Research has proved that those who diet — many of them involuntarily in parts of the world where food is in short supply — live longer and are healthier than those who eat more than their body needs. Skinny rats and mice, on a minimum diet, also live one-third longer than their gluttonous cousins.
The aim of the current research is not to increase life span, though this may prove to be a side effect. The scientists want to improve the health span, increasing quality rather than quantity of life for those who make it out of the rat race and into pension heaven.