Living a long life and staying healthy for most of those years may sound like the same thing.
Genetically, they are closely related-but they may not be identical.
Scientists studying aging therefore look at several different measures.
Lifespan tells us how long a person lives.
Healthspan asks a different question: how long does that person remain in good health, without major disease or loss of function?
Large genetic studies can compare these different outcomes and look for genetic differences associated with each of them.
And an interesting pattern is emerging.
Some genetic influences appear to be shared between lifespan and healthspan, while others may be more strongly associated with one than the other. This suggests that the biology that helps us survive to an older age is not necessarily identical to the biology that helps us remain healthy while getting there.
Why?
One reason is that our genes can influence many different aspects of aging.
Some genetic differences affect cholesterol and cardiovascular risk. Others are linked to inflammation, metabolism, immune function or DNA repair. These processes can influence when age-related diseases develop, how well the body maintains normal function and, ultimately, both healthspan and lifespan.
Researchers also study exceptional longevity and parental longevity-whether people who live unusually long lives, or whose parents did, share particular genetic characteristics.
Looking at these different measures gives scientists more information than lifespan alone.
A person may live to an advanced age but spend many years with chronic disease or disability. Another person may remain healthy and independent until relatively late in life.
Both may have similar lifespans, but very different healthspans.
Genetics may help researchers understand some of the biological differences behind these different patterns of aging.
This is why modern longevity research is increasingly interested not only in what helps people live longer, but also in what helps them remain healthier for longer.
For longevity medicine, that distinction matters. The aim is not simply to add years to life, but to understand the factors that may help preserve health during those additional years.
