The paper is not only a critical analysis of blue zones, but a plea against the whole field of extreme-age demography.

Mike Madrid, an anti-Trump Republican strategist who specialises in Latino voting trends, told the BBC that the problem with “demography is destiny” was that it risked treating all non-white Americans as an “aggrieved racial minority”.

Declining fertility rates are not just about people delaying parenthood, but about a growing trend of people not having children, says Brienna Perelli-Harris, professor of demography at the University of Southampton.

From other registers, the researchers retrieved information on morbidity, mortality and demography.

Victories in Indian elections aren't solely determined by a single factor - caste, demography and religious identity are other key predictors of support for a party.