Can a DNA test tell you how long you'll live?

What the science actually says

For a century, twin studies have tried to separate nature from nurture in how long people live. Their estimates cluster around a quarter: roughly 20 to 30 percent of the variation in lifespan tracks with genetics. More recently, analyses of enormous family trees noticed that couples tend to resemble each other, which had inflated the older numbers; once corrected, the genuinely heritable share looks lower still. Estimates still shift with method: a 2025 analysis puts the heritable part higher once accidental and infectious deaths are set aside. What does not shift is what follows.

The honest reading of all of it is the same. Most of how long, and how well, you live is written by what you do, where you live, and a large measure of chance. Your DNA sets a backdrop. It does not write the ending.

Why a longevity score is a probability, not a prediction

A polygenic score adds up the small effects of many common variants into a single number. It is a real and useful tool, but what it describes is an average across a population, not a verdict for one person. Two people with the same score can live decades apart. Sold as a lifespan or an age you will reach, it dresses a probability as a prophecy.

There is a further catch worth knowing. Most of these scores were built largely on people of European ancestry, and they transfer poorly to everyone else, often over or understating risk. A number that looks precise can simply be miscalibrated for you. APOE is the textbook example: the e4 variant raises the statistical odds of certain age-related conditions, yet plenty of people who carry it live long, healthy lives. A variant moves a probability. It does not decide an outcome.

What your DNA genuinely tells you

The useful question is not how long, but what to attend to, and when. Read honestly, your DNA shows tendencies: how you are built to age, what fuels you, how you respond to food, drink and medicines. Read early, those tendencies point to where your effort is worth the most, while small changes still compound. A result is not a verdict. It is a map of where to look.

That is the whole posture of a Precision Longevity Analysis: not a number that claims your future, but a few clear, informational changes drawn from your own biology, read by a person rather than generated by software.

This is informational and educational, not clinical or diagnostic. Nothing here predicts disease or lifespan, and anything of clinical consequence in your own analysis is flagged for you to bring to your physician.