We find many of these cases where people have died very young, even after carrying a healthy lifestyle. A new international study suggests that the answer is in our DNA.
UCLA geneticist Steve Horvath led a team of 65 scientists from seven countries to record the age related changes in human DNA, calculate the biological age and to estimate the life of a person. A greater biological age, regardless of their chronological age, consistently predicted an early death.
“Our research reveals valuable clues about what causes human aging, marking a first step towards the development of methods aimed at delaying the process,” said principal investigator Horvath, a professor of human genetics and biostatistics at the David Geffen School of UCLA Fielding School of Medicine and Public Health.
on the basis of 13 data sets, including the landmark Framingham Heart Study and the Health Initiative of Women, a consortium of 25 institutions analyzed DNA from blood samples of more than 13,000 people in the United States and Europe.
application of a variety of molecular methods, including a clock epigenetic developed by Horvath in 2013, scientists measured the aging rates of each individual. The clock calculates aging blood and other tissues by tracking methylation, a natural process that chemically alters DNA over time. By comparing the chronological age of the biological age of the blood, the scientists used the clock to predict the life expectancy of each person.
“We were surprised to see that the epigenetic watch was able to predict the life of Caucasians, Hispanics and African -Americans,” said first author Brian Chen.
“This rang true even after adjusting for traditional risk factors such as age, sex, smoking, body mass index, history of disease and blood cell counts,” added Chen. The results of the group, however, are not bode well for everyone.
“We found that 5 percent of the population ages a biological faster rate, resulting in a lower life expectancy,” Horvath said, adding, “The accelerated aging increases the risk of death these adults by 50 percent at any age “.
The preliminary finding may explain why some people die young, even when they follow a nutritious diet, exercise regularly, drink in moderation and do not smoke.
“While a healthy lifestyle can help extend life expectancy, our innate aging process prevents us cheat death forever,” he stressed Horvath. “With all the risk factors such as smoking, diabetes and hypertension predict mortality even stronger than the rate of aging itself epigenetics.”
Scientists have always sought to identify biomarkers for biological age, according to co-author Dr. Douglas Kiel.
“In geriatric medicine, we are always impressed by the difference between chronological age of our patients and age appear physiologically,” Kiel said.
“This study validates the use of DNA methylation as a biomarker for biological age. And if we can prove that DNA methylation accelerates aging, we can design strategies to slow down and maximize years of good a person’s health, “he added.
the precise role of epigenetic changes in aging and death, however, is still unknown, said co-author Dr. Themistocles Assimes, assistant professor of cardiovascular medicine at the School of Medicine at Stanford University .
“epigenetic changes associated with chronological aging is a direct cause of death in older People?” “Maybe just enhance the development of certain diseases – or paralyze the ability to resist disease progression after having taken root further research is needed to address these issues ..”
larger studies focused only on cases with well documented causes of death will help scientists unravel the relationship between age and disease-specific epigenetic he added.
in 2017, according to the World Health Organization, the number of people worldwide over age 65 will outnumber those under 5 years for the first time in recorded history. In 2050, the proportion of the world’s population over 60 will double from 11 to 22 percent. Many countries are ill-equipped to keep up with the high costs associated with illness and disability as more people live longer, Horvath said.
“We have to find interventions that prolong the healthy life of five to 20 years. We have no time, however, follow a person for decades to test whether a new drug works.” Horvath said. “The epigenetic clock enable scientists to quickly assess the effect of anti-aging therapies in just three years.”
The University of California has applied for a provisional patent on the epigenetic clock.
results are published in today’s issue of the journal Aging.