The guide

How to live longer: everything we know about longevity

By GyroscopeUpdated November 15, 202636 sources

Most of the extra years in a human life come from a few plain habits. Don’t smoke, get fit, get strong. In a study of 123,219 US health professionals, women who had five healthy habits at 50 could expect about 14 more years than women with none, and men about 12.

The longevity business sells something else. Pills that feed your cells, cold plunges, DNA clocks, a blue zone diet. Some of it is harmless, and none of it has added a year to a human life. The years people really gain come from not smoking, a fit heart and lungs, strong legs and blood pressure they keep down. Everything on this site hangs off that idea, and this page is the map.

Start with the natural route, if you want to and if you can. Your heart, muscles and blood vessels rebuild to match how you use them, and that’s the route with years attached. Medicine still has its place, since blood pressure and cholesterol drugs add years for the people who need them. How to live longer naturally has the order, and the simple plan at the end of this page puts it in ten steps you can send to someone.

The map

1. How long can a human live? The ceiling, and why the averages mislead.
2. Your life in weeks, drawn from the US life table, with the summers and the days with your parents that are left.
3. What actually kills people, decade by decade, and the risks behind it.
4. What we’re afraid of instead, sharks against stairs.
5. What adds the most years, 20 habits ranked by size.
6. Ten small changes you can start this week.
7. How to live longer naturally, before any pill.
8. Are blue zones real? The case file.
9. How to see it working, with free tests on your floor.
10. The simple plan, ten steps to start this week and pass on.

How long does a human get?

The number in the news is 79.0, the US average at birth in 2024. It’s the wrong number for almost every adult, because it counts every baby and young adult who died early. By the same 2024 death rates, the most common age to die is 89 for American women and 87 for men. A woman who reaches 65 can expect to live to about 86, and a man to about 83.

Where you live counts too. By the World Bank’s 2024 figures, Americans can expect about 5 years less than people in Japan, Italy or Spain, and for men about two thirds of the gap comes from deaths before 50. Life expectancy by country has every country and the reasons.

The ceiling is far above both. The oldest person whose age was fully checked, Jeanne Calment of Arles, died in 1997 at 122 years and 164 days. Nobody has come close since. One 2016 study put the usual maximum at about 115, and others think there’s no fixed limit at all. By the 2024 rates, more than half of Americans die in their 70s and 80s, and that’s the stretch the habits below push back.

How long can a human live? has the limits, the records and why the averages mislead. How long do people really live? has the numbers for your age.

What does that look like as a life?

Draw a life as squares, one a year, and it looks smaller than it feels. Here’s a 40-year-old American woman by the 2024 table. She has lived 40 squares, and women her age live to about 83 on average, so about 42 more summers and 2,232 more weekends. A quarter of them live past 92.

The time with family runs out faster than the years. Say you lived with your mom until 18, she’s 68 now and you see her once a month. By your 40th birthday you’ve already had about 97% of the days you’ll ever spend together, on average. Your life in weeks draws yours, square by square, with the days left with your parents and how Americans spend a lifetime.

What actually ends it?

Mostly slow diseases. Heart disease and cancer killed about 1.3 million Americans in 2024, more than the next eight causes put together. They build for 20 or 30 years before anyone notices, which is good news in one way, since the same few habits push back on most of them.

The order changes with age. From 25 to 44, accidents come first, and drug overdoses are the biggest kind of accident. From 45 to 64 it’s cancer. After 65 it’s heart disease. What actually kills people, decade by decade? has the charts and the risks behind each one.

And what do we worry about instead?

Sharks, plane crashes and terrorism. In a 2026 survey, 28% of Americans said they were afraid of sharks and 47% of a terrorist attack. Over a lifetime, an American’s odds of being killed by a shark are about 1 in 4.3 million. A fall is 1 in 89, and only 16% of people are afraid of falling on an uneven sidewalk.

Rare, sudden deaths make the news and slow, common ones don’t, so our fears end up almost upside down. What we’re afraid of against what kills us has the whole ladder.

Where do the extra years come from?

Since 1980, tens of thousands of American nurses have filled in long questionnaires on what they eat, how much they move, whether they smoke and how much they drink. In 1986, male health professionals started doing the same. In 2018 a Harvard team pooled 123,219 of them, followed for up to 34 years, and counted five habits: never smoking, a BMI of 18.5 to 24.9, at least 30 minutes a day of walking briskly or harder, a diet in the top 40 percent of a healthy eating score, and moderate drinking.

Two years later the same team asked how many of those years were healthy ones. At 50, women with four or five of the habits lived 34.4 years free of diabetes, heart disease and cancer, against 23.7 for women with none. The habits added years and made a bigger share of them healthy. (One of the five was moderate drinking, and later work found light drinking adds nothing once former drinkers are counted apart, so if you don’t drink, don’t start.)

The habits aren’t the same size, and their order is the most useful thing on this site.

• Don’t smoke. Smokers lost more than 10 years, and people who quit at 45 to 54 still gained about 6 back. What quitting gives back.
• Get fit. In 122,007 people who ran a treadmill test, the least fit quarter died at about 5 times the rate of the fittest 2 percent. vo2max.guide has how to raise it.
• Get strong. 90 to 119 minutes a week of lifting, on top of cardio, went with a 13% lower death rate in 147,374 Americans. strength.guide has a plan.

Then come blood pressure, a steady wake time, mostly whole food, a smaller waist and less drink. What adds the most years? ranks 20 habits by size, each with its study. Never add the numbers up, since the habits overlap.

Do small changes count?

They make up most of the list. Each 10 points (mmHg) off the top blood pressure number went with 13% fewer deaths in 123 trials, and a week of home readings tells you if you need it. bloodpressure.guide has how. Eleven minutes of brisk walking a day, about half the US minimum, went with a 23% lower death rate in a 2023 review that pooled 94 groups of people. Women who ate fried chicken once a week or more had a 13% higher death rate than women who ate none, and processing.guide has how to eat less of the packaged stuff.

Ten small changes lists the ones to start this week, each sized from its study, with the guide that covers it.

Isn’t it mostly genes?

It feels that way. Everyone knows a smoker who lived to 95 and a marathon runner who died at 50. But in 2,872 pairs of Danish twins born from 1870 to 1900, genes explained about a quarter of the differences in how long they lived, and a 2018 study of family trees linking about 400 million people put it well under a tenth. A 2026 study that modeled out deaths from infections and accidents put it nearer half, which still leaves the other half to everything else. Genes count most at the far end. Is how long you live mostly in your genes?

Think of two houses built the same year from the same bricks. One owner clears the gutters and fixes the roof the first winter it leaks, and the other doesn’t. Twenty years on, one house looks twenty years older. Your genes are the bricks, and the rest is upkeep.

What about the blue zones?

The places famous for people living to 100 make a good story with a messy record. Okinawan men had the longest lives in Japan in 1980 and 1985, and by 2020 they ranked 43rd of 47 prefectures. A demographer’s study, still a preprint, found that records of Americans living past 110 fell by 69 to 82 percent once states brought in birth certificates. In 2010, Tokyo’s “oldest man” turned out to have been dead for more than 30 years while his family collected his pension.

The habits the blue zones are known for still hold up in big studies with good records. Are blue zones real? goes through the case, the defense and what’s left to learn.

What’s sold and what’s shown

• NAD pills. NMN raised muscle insulin sensitivity in a 10-week trial in women with prediabetes. Nobody has shown it adds a year. Do longevity pills add years?
• DNA age tests. Some clocks gave results up to 9 years apart when the same sample was run twice. Are biological age tests accurate?
• Red wine. In 107 studies of 4.8 million people, light drinkers didn’t live longer than lifelong non-drinkers once former drinkers were counted separately. Does red wine help?
• 10,000 steps. The number came from the name of a 1965 Japanese pedometer. Do you need 10,000 steps?

Nobody has shown that any pill adds years to a healthy person, or that moving a biological age score changes how long anyone lives. Most of the numbers on this site come from following large groups of people, and healthy people tend to do healthy things, so the true effect of each habit could be smaller. That’s why we show ranges.

How do you see it working?

The tests that predict the most are free. Sit on the floor and stand up without your hands. In 4,282 adults aged 46 to 75, the lowest scores went with about 4 times the risk of a perfect 10 over 12 years. Stand on one leg for 10 seconds. Take a week of home blood pressure readings. Retest every couple of months and the numbers move. What should you measure first? has the list, and the floor test scores yours.

The simple plan

If you want more healthy years, these are the steps we’d take, biggest first. Each one is small, and each was tied to fewer deaths in large studies. The sizes overlap, so never add them up.

Your own estimate shows which habit is costing you the most years, so you know where to start, and the two-minute quiz turns the plan into your own short guide. Every tip and study on this site is in one list, each a line long, to pass on.