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People do differ in how quickly they age, and the disparity starts at a young age, a new study shows.
Researchers found that by the tender age of 45, people with a faster rate of "biological aging" were more likely to feel, function and look much older than they actually were. And this relative rush to old age began at the age of 20.
According to the authors of the study, the obtained data suggest that we need to look at aging differently.
"Aging is a lifelong process. It doesn't start suddenly at age 60," said lead researcher Maxwell Elliott, a postdoctoral fellow at Duke University in Durham.
Anyone who has ever known an energetic, intelligent 80-year-old or 50-year-old man burdened with health problems and physical disabilities knows that chronological age does not tell the whole story. This is recognized by the concept of biological aging – or the rate at which the body's systems deteriorate over time. But it is not clear when exactly people start to differ in the rates of biological aging.
New evidence suggests that the split is occurring quite early.
For the study, Elliott and his colleagues used data on more than 1000 New Zealanders who were followed from birth in the 1970s until age 45. The rate of their biological aging was tracked starting at age 26, based on indicators such as body fat, heart health, lung volume, markers of inflammation in the blood, and even tooth decay.
It turned out that people really differ greatly in the degree of biological aging: people with the slowest growth added only 0,4 "biological years" for each chronological year; in contrast, the fastest-aging participant added nearly 2,5 biological years for every chronological year.
By age 45, rapid biological aging was already showing some of the health indicators usually associated with old age. Compared to their peers, they moved more slowly, had less grip and more problems with balance, vision and hearing. The researchers found that differences in mental acuity were also evident.
On average, people with rapid aging scored lower on tests of memory performance and generally reported more forgetfulness in everyday life. Meanwhile, MRIs showed that they usually had more signs of thinning brain tissue.