Researchers have made a major discovery that might help slow the crippling effects of aging. The key, according to a new report in Nature, is ridding the body of old cells that can help cause age-related afflictions like cataracts and muscle degeneration. Could the fountain of youth be on the horizon? Here's what you should know:

Why does aging strain our bodies?
It's still a bit of a mystery. But one prime suspect has always been cells that have outlived their usefulness. Most young, healthy cells constantly divide to "keep body tissues and organs functioning properly," says Shirley S. Wang at The Wall Street Journal. But eventually cells stop splitting, leaving them in a state called senesence. This is a natural way for the body to keep cancer from spreading. But we lose the ability to clear these cells from our bodies as we age, leading to build-up that scientists have long believed might contribute to age-related problems from wrinkles to arthritis.

So what did these researchers do?
A team of scientists at the Mayo Clinic in Rochester, Minn., treated mice — engineered to age quickly — with a drug that kills senescent cells but leaves healthy ones alone. There was a dramatic delay in the age-related changes in mice treated from birth; those given the drug in old age stop deteriorating, although the treatment didn't reverse existing problems. Senescent cells produce harmful compounds that cause inflammation, which can cause dementia, atherosclerosis, and other ailments, the study's authors say. "Now that we know these senescent cells contribute to the process," lead researcher Jan van Dursen tells Bloomberg Businessweek, "we can think about ways to remove them."

And this could someday be applied to humans?
That's what researchers are excited about. "Aging research is a relatively young field," says Nicholas Wade at The New York Times, "in both mice and people." People have relatively few senescent cells — they account for 5 percent or less of the tissue in the elderly. But if these cells have a major impact on the body, killing them could have "large benefits with little downside." The goal, however, "is not to let people live a thousands years"; it's to ensure that our natural lives can be lived out "in good health."

Sources: Bloomberg Businessweek, NY Times, Wall St. Journal