Variants of a gene thought to be linked to longevity appear to influence aging into the 90s, but do not appear to affect exceptional longevity, or aging over 100, said a new study.
The discovery published in the Journals of Gerontology: Biological Sciences challenges previous findings that indicated some variants of the gene, FOXO3, played a role in exceptional longevity.
FOXO3 had gained quite a bit of attention over the last 10 years as a possible contributor to longevity across a variety of ethnic groups around the world, but despite a lot of research, the mechanism by which the gene helps people remains murky.
By examining genetic data is based on the blood samples of 2,072 older subjects from four centenarian studies: the New England Centenarian Study; the Southern Italian Centenarian Study; the Longevity Genes Project at Albert Einstein College of Medicine; and the U.S. National Institutes on Aging-funded Long Life Family Study. The new study was intended to better understand the gene's role in survival to not just the 90s, but beyond to even more exceptional ages.
The researchers found that FOXO3 did seem to play a role in longevity to a degree, but did not generally affect living to ages 96 or older for men, or 100 for women, namely the oldest 1 percent of the population.
"These variants (of FOXO3) did seem to have some impact, but they do not appear to be as influential toward truly exceptional longevity as previously thought," said Harold Bae, an assistant professor in the College of Public Health and Human Sciences at Oregon State University (OSU) and the lead author of the study. "These variants will help you live to a certain age, the early to mid-90s, but won't get you to exceptional longevity."
People who live into their 90s or 100s, beyond the typical life expectancy near 80 for adults, can offer important lessons about healthy aging, said Bae.
Centenarians experience slower aging throughout their lives, live independently well into their 90s and spend only the last few years of their exceptionally long lives with significant diseases or disabilities.
Unlike average aging, centenarians appear to benefit from combinations of longevity-enabling genes that likely protect against aging and age-related diseases and disability, said Paola Sebastiani, the paper's senior author who is from Boston University Schools of Medicine and Public Health,
"We attended presentations and read scientific papers claiming associations between FOXO3 variants and longevity, yet when we tested for these associations among centenarians, we were unable to reproduce the findings," said Thomas Perls, the director of the New England Centenarian Study, Boston Medical Center, and co-author of the paper. "We suspect that part of the reason may be because these earlier claims were coming from studies made up mostly of people in their 80s and 90s, and not those in their 100s."
Acknowledging in a news release from OSU on Tuesday that "there's still more to learn about this gene," Bae said the findings are likely to prompt new areas of research, as FOXO3 may not be a key to achieving truly exceptional age.