According to Horvath, the UCLA research points to an epigenetic explanation for Latinos’ longer life spans. For example, the biological clock measured Latino women’s age as 2.4 years younger than non-Latino women of the same age after menopause.
“We suspect that Latinos’ slower aging rate helps neutralize their higher health risks, particularly those related to obesity and inflammation,” said Horvath, who is also a professor of biostatistics at the Fielding School of Public Health at UCLA. “Our findings strongly suggest that genetic or environmental factors linked to ethnicity may influence how quickly a person ages and how long they live.”
The Tsimane aged even more slowly than Latinos. The biological clock calculated the age of their blood as two years younger than Latinos and four years younger than Caucasians. The finding reflects the group’s minimal signs of heart disease, diabetes, hypertension, obesity or clogged arteries.
“Despite frequent infections, the Tsimane people show very little evidence of the chronic diseases that commonly afflict modern society,” observed coauthor Michael Gurven, a professor of anthropology at UC Santa Barbara. “Our findings provide an interesting molecular explanation for their robust health.”
In another finding, the researchers learned that men’s blood and brain tissue ages faster than women’s from the same ethnic groups. The discovery could explain why women have a higher life expectancy than men.
Horvath and his colleagues next plan to study the aging rate of other human tissues and to identify the molecular mechanism that protects Latinos from aging. The research was supported by grants from the National Heart, Lung and Blood Institute and the National Institute on Aging.