Thursday, September 28, 2006

A slim chance to grow old

Maybe things aren't so bleak after all. According to an afternoon panel at the conference, scientists are making real progress in finding ways to extend the human lifespan, and to keep us healthy for however many years we linger.

There is, however, a downside. It seems the hottest idea in lifespan extension is "caloric restriction," an MIT way of saying that we have to eat less. A lot less.

Starting back in the 1930s, scientists found that animals lived substantially longer, showed less evidence of aging and had far fewer diseases like diabetes if they were fed 30 percent less than normal. Richard Weindruch, professor of medicine at the University of Wisconsin, is even working with pet food maker Purina to create foods that will extend the lives of animals.

Lenny Guarente of MIT's biology department said that they've got a pretty good idea of what's happening. There's a gene called SIR2 that moderates metabolism. The gene is activated in some unknown way by cutting back on food, and activating it leads to longer life in yeast and worms. There's a similar gene in humans called SIRT1. Mice that have been implanted with this gene have lower body fat, lower cholesterol, lower glucose and insulin levels, all indicators of rude good health.

So maybe we don't have to eat less. Maybe we can just find a drug that activates SIRT1 no matter what we eat. That's the plan at Sirtris Pharmaceuticals. CEO Christoph Westphal said his company isn't mainly interested in extending the human lifespan, but in keeping people healthier no matter how long they live. He thinks that activating SIRT1 will reduce the risk of Huntingtons, Parkinsons, Alzheimers and a host of other unpleasantness.

Boston University aging expert Thomas Perls reminded us that there are a lot of quacks promising eternal youth. "You can go back to the 1800s and they were marketing ground-up goat testicles," Perls said.

He praised the scientists on the panel but warned that preliminary reports of this or that anti-aging therapy always unleashes a horde of con artists, peddling untested cures on the Internet. The latest medical miracle: stem cell injections from quack clinics in the US and China.

"I think there's a real danger in going from petri dish to market," Perls warned the chortling crowd. "Be cautious out there."

Good idea. You might live longer.
(By Hiawatha Bray, Globe staff)

Posted by at 02:20 PM

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