You thought so at your last high school reunion and it just might be true -- some people age faster than others.
A new study finds that as early as age 38, some people are biologically much older. In fact, some look like they’re in their 60s, while others still look like 20-somethings.
And it’s not just on their medical tests. When college students were shown pictures of some of the volunteers in the study, they correctly picked out who was aging faster.
“Some of the people in our cohort had aged physiologically not at all between 26 and 38,” said Daniel Belsky of Duke University's Center for the Study of Aging and Human Development, who led the study.
“On the inside they looked the same -- the 12 years of time hadn’t passed. At the other end of the extreme there were folks aging two to three times as much.”
“On the inside they looked the same -- the 12 years of time hadn’t passed."
For their study, Belsky and colleagues used data from 950 people who have been taking part in a lifelong medical study since they were born at a hospital in Dunedin, New Zealand in 1972 and 1973. "They have been followed up at regular intervals ever since,” he said.
Belsky’s team came up with a batch of 18 measurements they believe correlate with aging. “We used medical measures of their lungs, their kidneys, their livers, their hearts, their immune system and even the integrity of their DNA,” he told NBC News.
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“We took their blood pressure. We measured their height, their weight, their waist circumference.” The researchers tested lung function and put everyone on an exercise bike to test their fitness.
They also measured IQ and compared scores to childhood tests, and asked people if they had trouble walking up stairs or carrying groceries.
Some of the 38-year-olds looked average, some even looked like they had at age 26. But some looked a lot older on the tests.
“They have higher blood pressure, higher cholesterol, higher levels of inflammation –- their immune system is all charged up,” Belsky said. “They probably aren’t breathing quite as well. And they may be overweight and having metabolic problems.”
“They have higher blood pressure, higher cholesterol, higher levels of inflammation – their immune system is all charged up."
Their scores on the tests looked like people who are in their 50s and 60s, Belsky’s team reported in the Proceedings of the National Academy of Sciences. “We know that later in life [these scores] do change with age,” he said.
It doesn’t boil down quote to a five-point “Are you aging too fast” test, but most of the tests are done on routine physicals, or could be, Belsky says.
And people can ask themselves how they feel. “We had them complete a bunch of physical function tests,” he said. They included tests of balance, coordination, strength, climbing stairs, and so on. “The study members who appeared to be aging faster in their physiologies were also doing less well on the physical function,” Belsky said. “They are only 38 years old, but already there’s variation in their balance, in the coordination, in their strength.”
And the intelligence tests were telling, too. “We know that as we age, we get a little less sharp,” Belsky said. “We saw that already by age 38, study members whose physiologies were aging faster were showing signs of cognitive decline.”
Perhaps most stunning, the aging-related changes showed up in people’s faces. The team showed high-resolution photographs to college students at Duke, who had no idea what the study was about or even that all the photographs showed 38-year-olds. They were asked to guess how old each person was.
“If you ever want to be convinced that aging is occurring at different rates in young adults, go to your 20th high school reunion and look around."
“These undergraduates guessed that the study members that were aging faster looked older,” Belsky said.
He’s calling it the 20th reunion effect. “If you ever want to be convinced that aging is occurring at different rates in young adults, go to your 20th high school reunion and look around,” he said.
What the researchers cannot say yet is whether the “fast” agers will die sooner, or if people can turn things around with lifestyle changes. They did not tell the individuals in the study how they scored, since they are not yet sure what it all means.
The team will continue to watch the New Zealand volunteers and will do another round of testing when they turn 45. And Belsky, who’s 35, says he may peek at some of his own measurements, too. Just in case.