Women who gave birth at age 40+ were ~4x more likely to live to 100. In this 1997 study, 19.2% of centenarians had kids ≥40, vs. just 5.5% of women who died at 73. This isn’t probably causal - it’s likely that the ability to conceive at 40 signals slower biological aging and better long-term health. Several other studies support these findings (PMID: 27854529; PMID: 24977462; PMID: 38964280) Graph: PMID: 9296486