Delaying aging and the infirmities associated with old age would make populations healthier overall and could save trillions of dollars over the next five decades, a new study says.

While research has focused largely on diseases such as cancer or heart disease, the elimination of these diseases would have less effect on longevity and quality of life than delaying aging itself, according to the study, which appears this month in Health Affairs.

This is because older people tend to suffer from a combination of ailments brought on by aging, said the study, which was conducted by scientists from the University of Southern California, Harvard University, Columbia University, the University of Illinois at Chicago and other institutions.

“When we treat someone with cancer, or heart disease, or stroke, we are treating a manifestation or byproduct of biological aging -- the underlying process marches on unaltered by this approach to disease,” said Jay Olshansky, a professor at the University of Illinois School of Public Health in Chicago and a co-author of the study.

“This means that even if we succeed for a time in extending life by treating disease, either that disease or another will emerge with time….Slowing aging alters the risk of all diseases simultaneously by attacking the origins of all of the things that go wrong with us as we grow older.”

The study cited research into the genetics of centenarians and animal studies of caloric restriction, as well as hormone manipulation, altering insulin-signaling pathways, and removal of senescent cells as showing potential for delaying the aging process.

The study coincides with Google’s September announcement that its next startup, Calico, will focus on delaying aging and extending the human lifespan. Another California-based company, SENS research foundation, also seeks to repair the damage done in the aging process.

Currently, a long life does not necessarily mean a healthy life; disability rates have increased along with life expectancy, the study said. The current population of young Americans is expected to have higher incidences of health problems like obesity and diabetes than their older counterparts, according to projections using federal data.

The number of Americans over 65, now around 43 million, is expected to more than double in the next fifty years, to 106 million. Around 28 percent are currently disabled, and the decades-long gains in the functional status of older Americans ended in 2002, the study said.

Even modest scientific advancements in delayed aging would result in an additional 11.7 million healthy people over 65 by 2060, according to the study. It would also raise life expectancy by around 2.2 years.

Delaying aging would be costly because of longer entitlement outlays, but the study said that the costs could be offset by raising the age for official Social Security retirement and Medicare eligibility to 68. It also predicted that delaying aging could save $7.1 trillion in the next fifty years, as people stay in the workforce longer and live without having major medical expenses associate with aging.