Many of us are familiar with the fact that the age of our parents when they conceive us may have a host of consequences in our later lives. But did you know that having an older father—and indeed, having an older grandfather—may bestow genetic advantages for a longer, healthier life? This is the startling finding that professor Dan Eisenberg, newly hired by the department, uncovered in his recent research.
Dan was a graduate student at Northwestern University when he first got involved in research on telomeres, the pieces of repeated DNA at the end of our chromosomes. At the time, evidence was accumulating that longer telomeres were a strong predictor of numerous positive health outcomes in populations around the world. Researchers found that telomeres get shorter across the lifespan but, counter-intuitively, people whose fathers were older actually had longer telomeres.
Dan was intrigued by the idea that this might be a marker, passed across generations, about the relative healthiness of our environments: a father who lives a long life indicates a relatively healthy environment, where it may be more adaptive to live longer and reproduce later and more slowly. And, he wondered, if this marker can pass across one generation, could it also move across two? Dan’s curiosity led him to connect with scholars conducting long-term research in Cebu Province, Philippines, where he was able to examine telomere lengths across multiple generations of families. From this work, he indeed discovered that a paternal grandfather’s age at the birth of a son independently predicted the length of that son’s children’s telomeres! The implications of this is astonishing in terms of our understanding of genetic inheritance and the ways in which our species has evolved to adapt to changing environments. A wide range of media—including NPR, the BBC, the Associated Press, and the Daily Mail—leaped at the occasion to highlight Dan’s research.
Dan is no newcomer to high-profile work, having done previous studies on the genetics of attention deficit hyperactivity disorder (ADHD) and its relationship to health outcomes among nomadic and settled communities of Kenyan pastoralists. His research indicated that, within settled communities, those people who had a form of a gene that predisposes for ADHD also had worse overall health outcomes than those who did not carry the gene. In the nomadic population, however, the opposite was true, namely those who displayed the gene had better health outcomes. This is just one of a growing number of examples of how what people in industrialized societies think of as a medical problem may very well be a medical advantage for people in other cultures. This leads us to question what, if anything, we can label as medically “normal” on a global scale.
So far, Dan is adapting well to his own new environment. He has already begun collaborations with faculty in the UW School of Nursing, examining biological markers of psychosocial stress among Filipino/a immigrants to the U.S. And he says that, as a vegan and avid bicycle commuter, it has not taken him long to feel at home in our own unique northwest culture.