What is longevity? Meaning, causes and what helps

What does longevity mean?

The word is used for two different things, and mixing them up is how most of the confusion starts.

Lifespan is how long you live. That is the number on a headline about somebody turning 110.

Longevity, as this field uses it, is about how many of those years you are well enough to use. That has its own word: healthspan, the stretch before your body starts holding you back. Nobody researching this is trying to add years in a chair.

That gap has been measured. Compare life expectancy with health-adjusted life expectancy and the world average comes out at roughly nine years ^[4]. Nine years you are alive for, with disease or disability.

And the gap opened because one half grew faster than the other: between 1950 and 2020 average life expectancy rose from 47 to 73, an expansion of 26 years ^[4]. We added years. The question this field asks is which kind.

How do you pronounce longevity?

Lon-JEV-i-tee. The stress lands on the second syllable, and the g sounds like the j in "jam".

How big is the gap in healthy years?

Life expectancy in most of Western Europe now sits comfortably above eighty. That is close to double what it was a century ago.

Except those extra years are not all healthy years.

Worldwide, life expectancy runs roughly a decade ahead of healthy life expectancy ^[4]. There is a stretch at the end of an average life where a person is still alive but living with a condition, on medication, with limits. The global burden of disease work maps the same thing: how many years people spend living with something rather than without it ^[3].

That gap is the subject. The question in this field is not "can we reach a hundred", it is "can we make those ten to twenty years shorter".

Why did aging become something you can study?

For a long time getting older was simply something that happened. You can study a disease, but how do you study time?

That changed in 2013, with a paper that broke aging down into nine measurable processes. By 2023 there were twelve ^{[2] [1]}. They are called the hallmarks of aging, and almost everything published in this field points back to them.

Six of the twelve, put plainly:

• Damage to your DNA, and repair that is not perfect.
• The caps on your chromosomes, which shorten every time a cell divides.
• Cells that stop dividing and then do not clear out.
• Mitochondria that deliver less energy than they used to.
• A metabolism that starts reading food differently.
• Low grade inflammation that climbs with the years.

What that list did was split aging into things you can measure, and therefore study. What it does not do is tell you how to repair them. Marketing tends to skip past that difference.

What is proven about longevity, and what is not?

This is where we have to be blunt, because this is exactly where it goes wrong.

No compound has been shown to extend lifespan in healthy people. Not one. The compounds that get talked about most are at various stages of research, and none of those stages are finished.

Metformin, an existing diabetes drug, is being studied as an aging intervention; the proposal for the large trial has been on the table for years ^[6]. Senolytics, drugs that clear out worn-out cells, look promising in animals and are at an early stage in humans ^[5].

What does work is well known, boring and free: move, sleep, do not smoke, drink little, eat enough protein, keep your muscle. There is no supplement whose evidence comes anywhere near what strength and endurance training do.

That is not the answer a longevity shop wants to give. It is here because it is true.

How much of longevity is genetics?

Less than almost everyone assumes, including the people who study it.

Family-tree studies have long put the heritability of lifespan somewhere around 15 to 30 percent, which already leaves most of it to something other than your parents. Then a 2018 analysis of over 400 million people found even that is inflated. The reason is unglamorous: people tend to marry people like themselves, and that similarity gets mistaken for shared genes. Correct for it and the real heritability drops to well under 10 percent ^[7].

So "my grandmother smoked until she was 94" is a worse guide to your own odds than what you did this week. That cuts both ways, which is the point: a bad family history is not a sentence, and a good one is not a pass.

Why do you hear about longevity everywhere?

Three things at once.

The research became usable, with the hallmarks as a framework. Measuring got cheap, because a blood panel, a sleep ring and a VO2max test are now within reach of ordinary people. And money arrived: clinics, supplements, devices, subscriptions.

That third one is why this article exists. The moment money enters a field, a gap opens between what the research says and what gets sold. That gap is usually exactly where the most beautiful promises are standing.

What is longevity escape velocity?

You will run into the phrase longevity escape velocity: the idea that if medicine starts adding more than a year of life expectancy per year, you never catch up with death.

It is a coherent thought experiment. It is not a finding, a forecast, or something anyone has measured. It gets quoted with a confidence the underlying evidence does not support, usually by someone whose product is meant to get you there. Treat it as an idea, not a plan.

What do we mean by longevity?

Longevity is not a product and not a protocol. It is a question: what can I do now that I will still benefit from in thirty years?

Everything we publish should answer that with sources attached, including the studies that found nothing. Where the evidence is weak, we say so. Where there is none, we say that too.

We sell products, so do not take our word for it. Click through to the study underneath. Every number on this site can be traced back.

Where can you read more about longevity?

If you want to see what this looks like in practice, start with one of our analyses. Each one takes a single subject, reads everything published on it, and reports what did not work as well. Two good places to start: what a biological age test actually measures, and why grip strength predicts how long you live.

The guides are the applied side: the same research, written out as something you can do. They are free and they stay free.