Humans do a lot to stop aging in its tracks. Yet, despite all efforts to eat healthy, exercise regularly and stay away from vices, people still die before they reach the century mark.
To that end, a geneticist from UCLA, Steve Horvath undertook a massive study involving 65 scientists across seven countries. The team analyzed samples from 13,000 people in the US and Europe to study age-related changes in human DNA. The research involved calculating a person’s biological age as a way to estimate his or her lifespan.
Using an epigenetic clock that Horvath developed in 2013, scientists calculated the age of blood and tissues. They then pegged the results of the epigenetic clock’s biological age calculations against the person’s chronological age to determine life expectancy – and according to their findings, a higher biological age led to an earlier death.
According to the researchers, the epigenetic clock could predict lifespans across different ethnicities, even after they have included typical risk factors such as age, gender, smoking, weight, and genetic history.
The team also revealed that five percent of the population ages faster on a biological level, and unfortunately, this also raises the risk of death by 50 percent, regardless of age. So for instance, if two people were both regular smokers, but Person A was included among the five percent who biologically aged faster, that person is more likely to die in the next 10 years, versus Person B.
These results could explain why some people, despite leading healthy lifestyles, die young. Because while eating well, exercising and avoiding drinking and smoking do help extend life expectancy, the body’s inherent aging process may have more to do with it.
The study also raises more questions – is death caused by epigenetic changes associated with chronological aging? Or does it merely spur diseases? What is the real role of epigenetic changes in aging or death? Despite this, the findings manage to point scientists in the right direction.
“Our research reveals valuable clues into what causes human aging, marking a first step toward developing targeted methods to slow the process,” said lead investigator Horvath.