Familial Longevity is Accompanied by Increased Healthspan
It remains unclear as to the degree to which familial longevity is a matter of culture versus genetics. Studies of ever-larger genetic databases are finding that human life expectancy has a smaller genetic component than previously thought, while smaller studies have found very few gene variants broadly correlated with longevity, none of which have large effect sizes. Separately, it continues to be the case that large epidemiological studies show lifestyle choices to produce a sizable effect on life expectancy. It is reasonable to argue that familial longevity is near all a matter of cultural transmission of lifestyle choice, but far from proven or settled, and certainly not the focus of the major research programs in this space, all of which study the genetics of longevity.
Globally, the lifespan of populations increases but the healthspan is lagging behind. Previous research showed that survival into extreme ages (longevity) clusters in families as illustrated by the increasing lifespan of study participants with each additional long-lived family member. Here we investigate whether the healthspan in such families follows a similar quantitative pattern using three-generational data from two databases, the Leiden Longevity Study (LLS, Netherlands) and the Swedish register data available in the Scanian Economic-Demographic Database (SEDD, Sweden). We study healthspan in 2,143 families containing index persons with 26 follow-up years and two ancestral generations, comprising 17,539 persons.
Studying these long-lived families is important to improve our understanding of the molecular and environmental mechanisms that protect from multimorbidity and promote a healthy survival up to high ages. In this study we showed that members of long-lived families have a delayed onset of disease, multimorbidity, and medication use as compared to their partners, thereby extending their healthspan with up to a decade. These members also postponed multimorbidity since those who were already diagnosed with an age-related disease had a 54% lower risk of having a second age-related disease compared to their partners.
An increasing number of long-lived ancestors, as measured with the Longevity Relatives Count (LRC) score, not only associates with a lower mortality at any moment in life it also associates, in a similar way, with a lower disease incidence during mid and later life (60-75 years): With every 10% increase in LRC score the yearly risk to develop an age-related disease decreased with 5% in the LLS, and 6% in the SEDD, maximizing to 50% and 60% respectively when all ancestors were long-lived.