Differences in 'genetic clock' may help them age more slowly than other ethnic groups, study finds.
Hispanics might carry genetic advantages that allow them to age at a slower rate than other ethnic groups, a new study finds.
A team of researchers led by Prof. Steve Horvath, of the David Geffen School of Medicine at UC Los Angeles, conducted DNA analysis using a “genetic clock,” and found that Hispanic people age at a slower rate than others because they are more resistant to natural processes that hamper cell repair and development. The biological clock, for instance, measured Hispanic females’ genetic age as 2.4 years younger than women from other ethnic of the same age after menopause.
These results help explain prior research showing that Hispanics in the United States have a longer life span than whites, blacks, Asians and other ethnic groups, Horvath said.
To know this, the researchers analyzed blood, saliva and lymphoblastoid samples collected from more than 5,000 people who had participated in a wide range of studies. Those participants included not only black, white and Latino Americans but also Han Chinese, members of the Tsimane Amerindian tribe in South America, a group of hunter-gatherers from a central African rainforest, and another group of African agrarians living in grasslands and open savannas.
To arrive at a single measure of a person’s biological age and then compute his or her speed of aging, the researchers measured epigenetic activity at 353 sites in the genome.
The investigators found that after accounting for differences in cell composition, the blood of Hispanics and the Tsimane aged more slowly than other groups.
Horvath emphasized that Latinos’ slower aging rate cannot be explained by lifestyle factors such as diet, socioeconomic status, education or obesity, because researchers adjusted for the influence of such factors.
The study may also shed light on a different demographic oddity: that once African Americans have reached the age of 85, they tend to live longer than whites of the same age. Using the new gauge of biological aging, the researchers found that older African Americans indeed age more slowly than do whites of the same chronological age.
"People have been looking for these biomarkers of aging for a long, long time. Many have sort of come and gone over time," Austad said. "The current status of the field is that there are no fully accepted biomarkers of aging."
Researchers looking to confirm this potential biological clock should test it on lab animals, where they can account for other factors that also influence aging, Austad said.
"The next step in research if they want to convince the field is to experiment on lab animals where we can control many, many things," he said. "It seems to me adding that to this human research would make this a much more compelling story."