There is a natural range of variation in the pace of aging that is largely determined by lifestyle until later old age, at which point genetic influences become more important. Aging is a global phenomenon throughout the body: if someone ages more rapidly, it tends to be the case that every manifestation of aging is worse at any given chronological age. So when researchers find ways to measure an aspect of aging at one age, it should be expected that this measure correlates statistically with differences in future life span.
Women who are able to have children after the age of 33 have a greater chance of living longer than women who had their last child before the age of 30. "Of course this does not mean women should wait to have children at older ages in order to improve their own chances of living longer. The age at last childbirth can be a rate of aging indicator. The natural ability to have a child at an older age likely indicates that a woman's reproductive system is aging slowly, and therefore so is the rest of her body."
The study was based on analysis of data from the Long Life Family Study (LLFS) - a biopsychosocial and genetic study of 551 families with many members living to exceptionally old ages. The study investigators determined the ages at which 462 women had their last child and how old those women lived to be. The research found that women who had their last child after the age of 33 years had twice the odds of living to 95 years or older compared with women who had their last child by age 29.
The findings also indicate that women may be the driving force behind the evolution of genetic variants that slow aging and decrease risk for age-related genes, which help people live to extreme old age. "If a woman has those variants, she is able to reproduce and bear children for a longer period of time, increasing her chances of passing down those genes to the next generation." The results of this study are consistent with other findings on the relationship between maternal age at birth of last child and exceptional longevity. Previously, the New England Centenarian Study found that women who gave birth to a child after the age of 40 were four times more likely to live to 100 than women who had their last child at a younger age.