Reported June 28, 2008

BIN those tarot cards and cancel the visit to the palm reader. It might one day be possible to predict how long you'll live from a sample of your white blood cells.

It is well known that the children of long-lived parents tend to be long-lived too, but no one knows why. As white blood cells fend off infection, in effect they are delaying death. So Sonya Vasto and her colleagues at the University of Palermo in Italy wondered whether these cells might hold any clues to longevity.

The team took samples of white blood cells from 45 men and women aged between 75 and 90, who all had parents born in Sicily between 1900 and 1908. Twenty-five of the donors had one parent who had reached 100 and one who had died of old age before reaching average life expectancy for Italians, which is 67 for men and 72 for women. The remaining 20 donors served as controls, having lost both parents before they reached average life expectancy.

The researchers found that the two groups differed in the number of naive B-cells, a type of white blood cell, that their blood contained. "Our main finding was the increase in naive B-cells in individuals who had centenarian parents," says Vasto, who is presenting the results this weekend at a conference on ageing in Los Angeles, organised by the Methuselah Foundation. Because the results are only preliminary, she will not disclose the extent of the increase as yet.