Genetics and Longevity: What Heritability Studies Show
What twin and family studies say about how much of human lifespan is inherited, with the APOE and FOXO3 findings, and why a longevity gene is not a personal prediction.
Content last updated . This page has not been medically reviewed.
Heritability: what the word means
Heritability is the share of the difference in a trait between people in a group that can be linked to genetic differences. It describes a population, not one person, and it says nothing about what any individual can change.| Study | Design | Result |
|---|---|---|
| Danish twins, published 1996 | 2,872 like-sex twin pairs born 1870 to 1900, nearly all followed until death | Heritability of longevity estimated at 0.26 for men and 0.23 for women; no evidence of a shared family environment effect [1] |
| Ancestry family trees, published 2018 | Pedigree data on hundreds of millions of historical persons | "Nominal" heritability matched earlier work, but much of the similarity also showed up among in-laws; after adjusting for people marrying partners with similar life-span factors, true heritability was well below 10% [2] |
The second study suggests that older estimates of 15 to 30% may be inflated by assortative mating, meaning people tend to pick partners who share genes or environments that affect life span. [2] Both findings are observational and based on people born in the 1800s and early 1900s, so they may not describe people today. Label: mixed (estimates differ by method).
Specific genes
APOE. A meta-analysis of genome-wide studies compared 11,262 people who reached the 90th survival percentile age and 3,484 who reached the 99th percentile with 25,483 controls. The APOE e4 variant was linked to lower odds of surviving to those ages and APOE e2 to higher odds. [3] It also found a gene near GPR78 linked to lower odds of reaching the 90th percentile age, and a shared genetic basis between health and longevity. [3] These are statistical associations in groups. They do not predict any one person's lifespan.FOXO3. In a study of long-lived men in a homogeneous population, variation in the FOXO3A gene was strongly associated with longevity (odds ratio 2.75 for homozygous minor versus major alleles), and the long-lived men also had lower rates of cancer and cardiovascular disease. [4] The work was chosen because insulin/IGF-1 signaling affects lifespan in animals, and the authors called for testing in other populations. [4] A later analysis of four longevity studies (8,266 people, cases aged 96 to 119) replicated 17 earlier FOXO3 variants linked to older age, but none of them changed the risk of dying beyond the oldest 1 percentile of survival. [5]
The worm gene daf-16, which is needed for the long life of daf-2 mutant worms, belongs to the same forkhead gene family as FOXO3. [6] That link is why FOXO3 drew interest, but it is not evidence that any treatment targeting it helps people. See Aging in Mice, Worms and Humans.
What this does not show
- No gene test predicts a lifespan. The studies describe odds in groups.
- Biology and environment overlap. Families share food, income and habits as well as genes. The Danish twin study found no evidence for a shared family environment effect, yet the Ancestry study found that in-laws, who are not genetic relatives, resembled each other in life span, which shows how hard the two are to separate. [1][2]
- Healthy-living advice does not need a gene result. Overviews of lifestyle research are in Nutrition, Exercise, Sleep and Prevention in Healthy Aging Research.
Frequently asked questions
How much of lifespan is genetic?
Estimates from twin studies were about 23 to 26% in one large Danish cohort, while a family-tree study that adjusted for assortative mating concluded the true figure was well below 10%. [1][2]
Is there a gene for living to 100?
No single gene. Several variants, including APOE and FOXO3A, are associated with reaching very old age in groups, but they do not predict individuals. [3][4]
Does APOE e4 mean I will die younger?
It is associated with lower odds of reaching very old ages in a large meta-analysis, but this is a group statistic and not a personal prediction. [3]
Do healthy habits matter if longevity is inherited?
Heritability estimates leave much of the variation to other factors, and heritability describes populations, not what any individual can change. [1]
More details: evidence, limits and cautions
The details behind this page: cautions, limits of the evidence and where sources disagree. Open any note to read it.
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References
- Herskind AM et al. The heritability of human longevity: a population-based study of 2872 Danish twin pairs born 1870-1900. Hum Genet 1996. PubMed 8786073. Read 2026-10-22.
- Ruby JG et al. Estimates of the heritability of human longevity are substantially inflated due to assortative mating. Genetics 2018. PubMed 30401766. Read 2026-10-22.
- Deelen J et al. A meta-analysis of genome-wide association studies identifies multiple longevity genes. Nat Commun 2019. PubMed 31413261. Read 2026-10-22.
- Willcox BJ et al. FOXO3A genotype is strongly associated with human longevity. Proc Natl Acad Sci USA 2008. PubMed 18765803. Read 2026-10-22.
- Effects of FOXO3 polymorphisms on survival to extreme longevity in four centenarian studies. J Gerontol A Biol Sci Med Sci 2018. PubMed 28977569. Read 2026-10-22.
- Kenyon C et al. daf-16: an HNF-3/forkhead family member that can function to double the life-span of Caenorhabditis elegans. Science 1997. PubMed 9360933. Read 2026-10-22.