Researchers are gaining deeper insights into the genetic factors that contribute to exceptional longevity, thanks to an renewal of an $80 million grant from the National Institute on Aging (NIA) of the National Institutes of Health (NIH). The funding will continue the Long Life Family Study (LLFS), a decades-long investigation into families with an unusually high prevalence of individuals living to advanced ages, often exceeding 100 years.
The LLFS, launched in , builds upon the Washington University School of Medicine in St. Louis’s established expertise in genetics and genomics, stemming from its significant contributions to the Human Genome Project. Researchers are analyzing the complete genetic makeup of study participants to identify clues that explain why some individuals enjoy remarkably long and healthy lives.
Unraveling the Secrets of Healthy Aging
Over the past two decades, the study has revealed that long-lived families generally exhibit better cardiovascular health compared to the average population, characterized by healthier blood pressure levels and lower rates of diabetes. This observation is particularly relevant given the global trend of an aging population and the projected doubling of individuals over age 50 with chronic conditions – including cardiovascular disease, diabetes, and Alzheimer’s disease – by .
“So much of medical research is focused on genetic problems that cause disease, and importantly so – we have learned a tremendous amount from that strategy,” explains Michael A. Province, PhD, principal investigator of the LLFS and a professor in the Department of Genetics at WashU Medicine. “But I am also fascinated by the opposite question: are there genetic variants that cause good things to happen in the body? Our study suggests that there is a wide variety of genetic ways that these long-lived families could be protected from chronic diseases as they age.”
The LLFS currently encompasses more than 5,000 participants from over 530 families residing in the U.S. And Denmark. The initial cohort, enrolled in , consisted of individuals averaging 90 years of age, with several living past 110. The study’s multi-generational design – now including the children of the original participants in their 80s and grandchildren in their 50s and 60s – allows researchers to analyze inherited genetic variations that may protect against age-related diseases across multiple generations. This approach is complemented by comparisons to the Framingham Heart Study, a long-running investigation tracking families in Framingham, Massachusetts, since .
Diverse Pathways to Longevity
Recent analyses have indicated that families don’t experience exceptional health in a uniform manner, suggesting multiple genetic pathways to longevity. Some families demonstrate superior cognitive function or blood pressure control, while others exhibit robust lung function or grip strength. However, a consistent finding is a lower incidence of diabetes among these long-lived families.
Researchers identified a genetic variant associated with lower hemoglobin A1c levels – a key measure used to diagnose diabetes – within these families. Despite maintaining similar rates of obesity compared to the general population (as seen in the Framingham Heart Study), long-lived families exhibit roughly half the expected cases of diabetes. “Something is protecting them from diseases associated with obesity,” says Province, “and we’d love to find out what that is.”
Unexpected Genetic Links
The study has also uncovered intriguing, and sometimes paradoxical, genetic associations. Researchers identified a novel gene linked to late-onset Alzheimer’s disease and, unexpectedly, a genetic variant associated with both extreme longevity and lower blood pressure, but also a slightly increased risk of head and neck cancer. The researchers emphasize the need for caution when developing therapies targeting rare genetic variants, acknowledging that these variants may have both beneficial and detrimental health effects.
Advancing Sequencing Technology
A significant component of the renewed funding will support a re-analysis of whole genomes from all current and past participants using the latest “long-read” sequencing technology. This advanced technology, including PacBio’s Revio system, can resolve previously unreadable portions of the genome – often referred to as “dark matter” – that were missed by earlier short-read sequencing methods. The study aims to expand its participant base to 7,800 individuals.
Researchers are actively seeking to enroll new families with exceptionally long-lived members and are prioritizing increased diversity within the study population, particularly families of African ancestry. “The larger and more diverse our dataset, the better we will be able to identify inherited genetic variants associated with longevity and then distinguish which are causing the protective effects and which are just inherited and ‘along for the ride,’ so to speak,” Province explains. “This is a critical question as we seek possible ways to replicate these protective effects for people without the beneficial genetic variations.”
The Long Life Family Study is a collaborative effort involving researchers from multiple institutions, including Boston University, Columbia University, the University of Pittsburgh, the University of Minnesota, Duke University, Johns Hopkins University, the University of Maryland, Tufts University, Georgia State University, and the University of Southern Denmark.
