Scientists have often noted that Latino Americans live longer, on average, than other groups, despite having higher rates of type 2 diabetes and other conditions. And now they may have a new clue as to why: According to a study from UCLA and UC Santa Barbara, their DNA actually seems to age more slowly than that of other people.
This finding may help explain the so-called “Hispanic paradox,” the name researchers have given to the group’s surprising longevity. Latinos in the United States have an average life expectancy of 82, according to the Centers for Disease Control and Prevention, compared to 79 for non-Hispanic white people.
It may also, the study authors hope, help scientists better understand how to slow the aging process for everyone.
To study the genetic differences between different groups, researchers analyzed blood samples from more than 6,000 people—including Africans, African-Americans, Caucasians, East Asians, Latino Americans, and Tsimane. (The Tsimane are an indigenous population native to Bolivia.) They used a statistical model known as the epigenetic clock to calculate the rate of cellular aging, based on many different biomarkers that change throughout a typical lifespan.
Epigenetics is the study of how and why certain genes are expressed, or turned on and off. Your epigenetic profile—and, therefore, epigenetic age—is influenced by the DNA you're born with, but also by your everyday experiences and your physical and social environment.
“This new measure is arguably one of the best biomarkers of aging out there today,” says co-author Michael Gurven, PhD, a UCSB professor of anthropology. “It’s indeed a biological measure, but tells a different story than conventional genetic differences.”
After accounting for differences in cell composition and socioeconomic status, the researchers found that the blood of Latino Americans and the Tsimane aged more slowly than that of other groups. For example, Latino American women measured 2.4 years younger than non-Latino women of the same age after menopause.
Co-author and UCLA professor Steve Horvath, PhD, who first described the epigenetic clock in 2013, says that something related to Latino heritage—either genetic or environmental factors, or a combination of both—seems to provide a protective effect. "We suspect that Latinos' slower aging rate helps neutralize their higher health risks, particularly those related to obesity and inflammation,” he said in a press release.
Strong family ties found in many Latino American communities may be one possible explanation for this effect, says Gurven. “Such a social support network may leave its biological signature in the epigenome," he says. “In fact, how the social environment and psychosocial stress affect disease risk and aging is getting a lot of attention right now.”
The Tsimane—a group with low rates of heart disease, diabetes, hypertension, and obesity—aged even more slowly than Latino Americans in the study. The researchers also found that women’s blood aged more slowly than men’s of the same ethnic groups. This could potentially explain why women have a higher life expectancy than men, they say.
So does this mean that people should start living more like Latinos—or that Latinos shouldn’t worry so much about following a healthy lifestyle? Not so fast, Gurven says.
“I’d say the study shouldn’t change your habits either way, because we don’t yet know the source of the epigenetic alterations,” he says. He also points out that these differences only appeared in adults over 35.
The authors conclude that Latinos’ longevity likely has something to do with how their DNA is being modified, “presumably by life experience, stresses, diet, and other factors,” says Gurven. In other words, it’s not all about the genes you’re born with. “So no free pass simply for being Hispanic,” he says, “and, similarly, non-Hispanics shouldn’t lose hope.”