U.S. biologists say they've uncovered a gene in fruit flies that may retard aging and result in longer lives by increasing the body's ability to eliminate cellular debris associated with a number of age-related diseases.

The gene can retard the aging process in the entire the body when it is activated remotely inside some key organ systems, suggesting important implications for slowing aging and disease in humans, researchers at UCLA report.

When the gene, known as AMPK, was activated in fruit flies, the life span of the insects was increased by almost a third -- to around  8 weeks instead of the normal 6 --- with improved health throughout that time, the biologists said.

"This research brings us closer to understanding aging at a cellular level and has implications for delaying the onset and slowing the progression of many of the major diseases of aging," says senior study author David Walker.

AMPK is involved in a bodily process called autophagy, a housekeeping process at the cellular level that allows the body to flush out damaging cellular waste products.

Activating the gene in just one body system can have an effect throughout the whole body, the researchers found.

"We have shown that when we activate the gene in the intestine or the nervous system, we see the aging process is slowed beyond the organ system in which the gene is activated," Walker says.

The AMPK gene is present in humans, but not normally activated at high levels, he says.

The findings on the effect in the fruit flies is significant for human applications, the researchers say, because while extending human life spans would mean protecting many organs from the effects of aging, delivering anti-aging therapies to some of them -- particularly the brain and some other important organs -- presents technical challenges.

Activating AMPK in a some more easily accessible organ system such as the intestines, as was done in the fruit flies, could possibly retard the aging process in the entire body, including the brain, they say.

"Instead of studying the diseases of aging -- Parkinson's disease, Alzheimer's disease, cancer, stroke, cardiovascular disease, diabetes -- one by one, we believe it may be possible to intervene in the aging process and delay the onset of many of these diseases," Walker says.

Such advances could take much more research and many years, he acknowledges, but he calls the goal a realistic one.

"The ultimate aim of our research is to promote healthy aging in people," he says.