For many years, scientists in Leiden have been monitoring 421 exceptional families with several members who have lived way beyond the age of 90. A new analysis of these extremely long-lived persons, their siblings, and parents now shows that longevity in these families is passed on mainly through the mother. The researchers present their results in the scientific journal The Journal of Gerontology: Biological Sciences. (press release LUMC)
‘From our analysis of the 944 extremely long-lived men and women monitored in the Leiden Longevity Study, we know that they live longer than people born in the same year and that they are not affected by age related diseases until later in life. We also know that their parents and siblings outlive their birth cohort members. And this, despite two centuries of infections, famine and war,’ explains Eline Slagboom, professor of Molecular Epidemiology.
In a new analysis, PhD student Niels van den Berg found that especially the extremely long-lived mothers pass on longevity to their children, and not the longest-lived fathers. ‘Children of a long-lived mother and a non-long-lived father outlive children of a long-lived father and a non-long-lived mother, or of two parents who are not long-lived. However, this only applies to families where the mothers are in the top one percent longest survivors of her birth cohort,’ says van den Berg. The researchers also observed that the survival advantage of these family members does not begin later in life; rather, they have a greater chance of survival than their contemporaries right from birth.
Mitochondrial DNA from the mother
According to the researchers, the finding that longevity is passed on mainly through the maternal ties is in line with in with the notion that predisposition to longevity lies in the so-called mitochondrial DNA. In contrast with the nuclear DNA, a child receives its mitochondrial DNA only from its mother, not from both parents. Another explanation may be that long-lived mothers in the late nineteenth century were physically healthier and therefore had larger and healthier babies than mothers who were not long-lived. ‘We had expected the affluence of long-lived fathers in this historical period to have an impact as well, but it seems that the mother’s physiology is much more important in extreme longevity,’ in our study explains Slagboom.
Only the best families
The finding brings science a step closer to the holy grail of aging research: identifying the genes for a long life. ‘We now know even more precisely whose genes we need to map in order to find out why some people survive into extreme old age but also, and above all, why they age healthily. Lifespan in the general population not very heritable, so our research confirms that it’s only in the rare families who have already survived longer than ordinary mortals over the past two centuries that we stand a chance of finding something,’ says Slagboom.