LOS ANGELES, Sept. 28 (UPI) -- An international study led by researchers from the University of California Los Angeles suggests life expectancy is at least partially dependent on genetics, regardless of lifestyle choices.
The research was led by UCLA geneticist Steve Horvath, who collaborated with 65 other scientists from around the world in analyzing blood samples collected from over 13,000 people. The findings were published in the latest issue of Aging.
An epigenetic clock previously developed by Horvath was used to calculate the aging of blood and other tissues by tracking DNA alterations over time. The clock is capable of measuring a blood sample's biological age, which UCLA scientists say can trump chronological age in determining when someone will die.
The research referenced 13 sets of data. According to Horvath, healthy eating habits coupled with exercise may not do much to postpone the end of life for some people.
"We discovered that 5 percent of the population ages at a faster biological rate, resulting in a shorter life expectancy," Horvath said in a press release. "Accelerated aging increases these adults' risk of death by 50 percent at any age."
The study's lead author adds risky activities such as smoking can still accelerate the aging process, but genetics nonetheless play a powerful role.
"While a healthful lifestyle may help extend life expectancy, our innate aging process prevents us from cheating death forever," Horvath continued. "Yet risk factors like smoking, diabetes and high blood pressure still predict mortality more strongly than one's epigenetic aging rate."
Despite the study's findings, medical professionals maintain the extent of the epigenetic clock's ability to predict lifespans is uncertain.
"Do the epigenetic changes associated with chronological aging directly cause death in older people?" said Stanford's Dr. Themistocles Assimes, the study's coauthor. "Perhaps they merely enhance the development of certain diseases -- or cripple one's ability to resist the progression of disease after it has taken root. Future research is needed to address these questions."