What is longevity? Lifespan, healthspan and the science between them

Lifespan is how long you live. Healthspan is how long you live free of serious disease and disability. In most countries the two are roughly a decade apart: people live into their late seventies or eighties, and spend the last several years of that managing chronic illness.

Longevity medicine tries to close that gap. The goal is less a record number of birthdays than a long life in which the final years look much like the ones before them.

Ageing is the largest risk factor for heart disease, cancer, type 2 diabetes and dementia. Researchers who study it look for the processes those diseases share, in the hope that slowing the process delays all of them at once. The processes most often named include chronic low-grade inflammation, the accumulation of worn-out cells, changes in how genes are switched on and off, and declining function of the mitochondria that power cells.

Much of this work is still in animals. The drugs that extend life in mice have not yet been shown to extend it in people, which is why claims built on them deserve caution.

The strongest evidence in humans is unglamorous and consistent.

• Cardiorespiratory fitness and muscle strength: both are strongly associated with living longer and staying independent.
• Not smoking, and drinking little alcohol.
• Sleep of sufficient length and regularity.
• A diet built on vegetables, legumes, whole grains, fish and olive oil, and a stable, healthy weight.
• Controlling blood pressure, blood lipids and blood sugar early, with medication when lifestyle is not enough.
• Screening that finds cancer and heart disease while they are still treatable.
• Close relationships and a sense of purpose, which show up in long-term studies as reliably as the physical factors.

General advice is the same for everyone. What differs is which risk is yours. One person's weak point is inherited cholesterol, another's is blood sugar, a third's is bone density. This is where measurement earns its place: detailed blood work, body composition, fitness testing and imaging show where to spend the effort. We describe that process in what a longevity clinic does, and one of its more debated tools in biological age tests.

LACE was founded by scientists to make that kind of personal, evidence-led longevity available to private clients, through longevity travel to clinics and retreats it has evaluated, and through private services that bring physicians, nutrition and a healthy home to the client. The Scientific HUB connects the researchers and clinicians behind it.