"The oxidants are very similar to what one sees in a nuclear explosion, or a nuclear reaction," says Hagen, an associate professor of biochemistry and biophysics at Oregon State. "So we are constantly irradiating ourselves via the mitochondria throughout our lives."
The production of free radicals increases as we age, leading Ames and Hagen to speculate that the mitochondria plays a key role in aging. So they began experimenting with two substances used by the mitochondria, lipoic acid and carnitine. Lipoic acid is used to convert fuel to energy, and carnitine is the "glue" that attaches to the fuel and hauls it into the power plant.
"To make a long story short, we found that carnitine levels decline precipitously with age," Hagen says. "We don't make enough of it as we get older."
So the researchers began giving supplements to rats in hopes of increasing the performance of the mitochondria.
"We're trying to see where we can tune up, or maintain a level that should be there but isn't," Hagen says.
What they found is now history. The rats performed like troopers, but will the same nutrients do the same for humans? Are they safe? These nutrients function as drugs, though not yet approved by the FDA for that purpose, and all drugs have some side effects. Lipoic acid, for example, is also an insulin regulator, so diabetics should not experiment with it.
The researchers haven't found the fountain of youth. According to the National Institute on Aging, one of several sponsors of the research, aging is a very complex process that is still poorly understood. There are at least 300 theories about why and how we age, and there is a general consensus that we will not see a significant increase in human life span for decades, or centuries, if at all.
That doesn't trouble Hagen because that's not really what he and Ames are looking for. They want to help us remain as healthy and as young as possible, right up until the end.
That goal fits nicely with the vision of the man whose name hangs over the door of the institute where Hagen now works. Two-time Nobel prize-winner Linus Pauling predicted decades ago that free radicals, or other oxidants, were causing many of our problems, including age-related declines. That's why he vociferously pushed for vitamin C, a natural antioxidant.
But like most of us, he hated the thought of getting old. I know that because a number of years ago I celebrated his 90th birthday with him. I followed him around for three days, from his fabulous estate on California's Big Sur coastline to Stanford University, where he taught a graduate seminar on chemistry.
While delivering his lecture, Pauling forgot something he was about to say. That happens to all of us from time to time, but the grand old man of science looked terrified as he stood speechless in front of his young audience. They probably figured he was getting senile.
Pulling himself together, he finally said, "I guess you're all wondering what we're doing over at the institute."
He picked up a piece of chalk and wrote a formula on one of three huge blackboards that blanketed three walls in the lecture hall. For nearly an hour, he expanded on the formula until it filled all three walls. Then he turned to the students, who sat with their mouths hanging open in absolute awe.
"Any questions?" he asked.
Not a one.
Now there's a man who knew how to stay young.
Lee Dye’s column appears weekly on ABCNEWS.com. A former science writer for the Los Angeles Times, he now lives in Juneau, Alaska.