Historical demography

Living to age 110

Next October, demographer Bertrand Desjardins of Université de Montréal will go to Sardinia to follow a very special lead. On this island there is apparently an abnormally high concentration of supercentenarians, individuals aged 110 years and over. What is exceptional about this is that most of the Sardinians who reach this respectable age are men.

“According to data demographers have been able to verify, no man has ever reached 110 years of age in Canada ,” Bertrand Desjardins reports. “The only supercentenarians that have been identified to date were women.” Contrary to popular belief, the longevity of women is not linked to environmental factors alone. Of course, men are exposed to more risks: they drive more and, until recently, they smoked more and held more stressful jobs. But there’s more to the story.

“There appears to be a genetic or biological component to longevity in women,” remarks Professor Robert Bourbeau, Chairman of the Department of Demography and a specialist in the study of mortality and longevity. “During the first year of life, there is already higher mortality among boys. It also seems that female hormones protect women, to some extent, from cardiovascular disease.”

The researchers were sceptical when Sardinian doctors presented their data at a colloquium held in Montpellier in 1997. “We were not very kind to them,” Mr. Desjardins recalls. “We saw their tables, noted that they were mainly men and immediately, we thought that it was a classic error. We advised them to go back and do their homework.”

It is important to note that the history of demography is strewn with instances in which, for all sorts of reasons, the ages of inhabitants in some regions have been inflated. A classic case is Georgia , a republic in the former USSR where Stalin was born. To pay tribute to the politician, the history books used to speak frequently of “very old” Georgians. Since that time, the data have been checked and the stories have been completely deflated.

“We often come up against myths like that,” Mr. Desjardins notes. It’s not always deliberate falsification. In some countries, there are no organized birth registers. Often you have to rely on individuals to estimate the age at death. At first, we thought that this was the case in Sardinia . But since then, the statistical data have been checked and it would appear we’re dealing with something serious. Because Sardinians baptize their newborns, the registries are fairly reliable.”

Bertrand Desjardins, who currently acts as a consultant on the Sardinian project, will not be the only person visiting the island. Geneticists, nutritionists, sociologists, and historians from around the world are taking part in the research.