By Mitch Leslie, ScienceNOW

Humans have been looking for a way to slow aging likely since the first person got wrinkles. A new study shows that the quest could be worthwhile. Scientists have found that even a moderate decrease in aging would boost our lifespans by more than 2 years and stave off ill health in many elderly folks. But the advance could also send the costs of Social Security and Medicare soaring.

Slowing aging is no fantasy. Researchers can delay how rapidly lab animals such as mice and roundworms grow old with a variety of measures, from genetic tinkering to extremely low-calorie diets. So far, however, nobody has shown that any drug or diet can postpone human senescence.

But some scientists, including demographer S. Jay Olshansky of the University of Illinois, Chicago, argue that we now know enough about aging to start an intensive, multiyear search for ways to delay it in people—a sort-of Manhattan Project for longevity. “Aging is the underlying risk factor for most of the things that go wrong with us” as we grow older, he says. That means slowing the process would not just add years to our lives, but it would also postpone illnesses such as cancer, diabetes, and heart disease that primarily strike the elderly. In the new study, Olshansky and colleagues attempted to estimate the payoffs and pitfalls, including financial costs, of delayed aging.

Using a simulation called the Future Elderly Model, the researchers asked what would happen if some sort of elixir were available for the whole U.S. population between 2010 and 2030 that cut the death rate from age-related causes by 20%. In this scenario, people would still perish from heart disease, cancer, and other illnesses, but they’d be older when they became sick. “We think of this as broad-based prevention,” says lead author Dana Goldman, a health economist at the University of Southern California in Los Angeles.

The results of the simulation suggest that slowing aging would lengthen life expectancy by 2.2 years over the status quo, the researchers report online this week in Health Affairs. Under current projections, for example, a person who is 51 years old in 2030 will likely live to about age 87. But under the slowed-aging model, that person would likely survive to 89. Moreover, delaying aging provided a bigger boost than did progress against individual diseases. Cutting the risk of developing cancer or heart disease by 25% would add only a year to that 51-year-old’s life, the researchers conclude.

An extra couple of years might not be very attractive if you’re going to be sick and decrepit. But slowing aging would also allow about 5% more seniors to avoid infirmity between 2030 and 2060 than would reductions in cancer or heart disease alone. “To my friends who want to live forever, I say it makes for great science fiction,” Olshansky says. “Our goal is to extend healthy life, not necessarily life itself.”

But as Olshansky notes, “there is a price to be paid for producing more healthy older people.” The model revealed that under the delayed aging scenario, Medicare and Medicaid would require $300 billion more in 2060 than under the status quo. Overall, the increase in longevity would translate into a budget shortfall for entitlement programs such as Medicare and Social Security of $420 billion in 2060.

These fiscal woes are obstacles—but not insurmountable ones, Goldman says. “The social and fiscal challenges are easily manageable with rational public policy.” For instance, the team calculated that it could eliminate the funding gap with a gradual, 3-year increase in the Medicare eligibility age and a 1-year increase in the Social Security eligibility age.

Although researchers had a general idea of the consequences of slowing aging, “it’s nice to have numbers,” says biogerontologist Steven Austad of the University of Texas Health Science Center in San Antonio. “The impact in terms of overall quality of life is quite substantial,” says geriatric oncologist Harvey Cohen of Duke University Medical Center in Durham, North Carolina, who wasn’t involved with the research. And by exploring the effects of reduced aging on social programs, the study uncovers “a reality that has to be dealt with,” he says.

Olshansky belongs to the Longevity Dividend Initiative (LDI), a group of researchers and organizations that has been talking up the payoffs of postponing human aging. “The question we addressed here—it’s absolutely critical we have an answer to it before we move on,” Olshansky says. Now, he and his colleagues are ready to take the next step, he says. In 2014, the LDI plans to start raising money, mainly from nongovernmental organizations and private individuals, to fund research to develop age-fighting measures, Olshansky says. Although researchers are already studying many potential options, the LDI’s goal is to usher them into human studies and possible use.

What these measures will be is a mystery—though almost every researcher has his or her favorite that works in lab animals. As for the timing, scientists caution that we’ll probably have to wait decades for the fruits of this work to reach the public.

This story provided by ScienceNOW, the daily online news service of the journal Science.