Aging study reveals how old you really are

Researchers say they may have found a way to identify the beginnings of the aging process in young people, according to a study published Monday in the Proceedings of the National Academy of Science. The results show that people age at drastically different rates in a way that is detectable as early as a person's twenties.

The #link:http://sites.duke.edu/danbelsky/quantification-of-biological-aging-in-young-adults/: study from researchers in the United States at Duke University# could help in the fight against age-related diseases.

Their work sets a new metric for how to measure aging in young people, reversing a previous notion that young people don't show signs of aging. The results could help in the development of preventative medicines that may eventually slow the onset or even prevent age-related diseases, but Terrie Moffitt, a senior author on the study and professor of psychology and neuroscience at Duke University, cautioned that this doesn't mean a cure for aging is around the corner.

The long road to human treatments

"People are starting to develop treatments, starting with yeast, and working up to worms, and then to mice, and then to monkeys," Moffitt told DW. "But jumping that gap from experimental animals to humans hasn't happened."

This new measurement that Moffitt and her colleagues, led by Dan Belsky, developed will help researchers who do wish to study the effects of a potential rejuvenation therapy on humans.

"[The study] is very simply the development of a measurement technology," Moffitt said, adding that other scientists would be able to make use of her team's work to measure aging.

The Duke researchers studied 954 people born in Dunedin, New Zealand, in 1972 and 1973 by measuring a total of 18 biological and bodily functions, including kidney, lung and liver function, dental health, and metabolism. Participants were measured at the ages of 26, 32 and 38.

Aging before their time

While most participants in the study aged one biological year with every chronological year some were aging by as much as three biological years for every chronological year, meaning their bodies and minds were deteriorating faster than their age would belie. At the end of the study, some of the 38-year-old subjects had biological ages approaching 60. Others had biological ages lower than their chronological ages.

"Before midlife, individuals who were aging more rapidly were less physically able, showed cognitive decline and brain aging, self-reported worse health and looked older," the study said.

In addition, participants with older biological ages, and who had a higher "pace of aging," scored lower on IQ tests and various biometric tests, including tests of balance and strength. When students from Duke University were shown photographs of all the subjects, they consistently rated those with a more advanced biological age as "looking older" than their chronological age.

Researchers acknowledged several limitations in the study, including a total lack of participation by ethnic minorities.

Studies in the United States have shown that the biometric markers of aging are different in African Americans than they are in Caucasians, Moffitt said, which would necessitate studying people of different races in different experiment groups. While the research team did have willing people of Maori descent, there weren't enough to constitute a statistically significant group, she added explaining the lack of diversity in the test subjects.

Coping with a graying society

The ability of doctors to catch and cure an age-related disease such as Alzheimer's is becoming more important as the average age of the global population creeps upward, the study said. Researchers estimate that by 2050, there will be three times as many 80-year-old people as there are today. Age-related diseases can also have huge, detrimental effects on a country's social structure and economic system.

But catching the progress of such diseases early enough to significantly reverse its effects means targeting interventions at young people. Previously, there was no effective way to test how quickly a person in their twenties was aging to determine whether they could begin treatments for a disease they might get in their sixties.

Most research on aging is done on people who are already old, Moffitt said.

"If your aim is slow aging and prevent disease, sooner or later we're going to have to take the leap and do this in young people," she added.

The next step, Moffitt said, is to determine the causes of advanced aging, which is one of the next studies she and her team have planned in the next year.