Living to 100 could become commonplace if current scientific explration proves successful. Making it to 120 could become “a perfectly reasonable aspiration”. That is the assessment of the Economist in its latest Technology Quarterly. One potential pathway to slow the effects of ageing is though drugs that appear to achieve the same results as severe calorie restriction. One, about to be trialled in the US is metformin, approved as a weapon against type-2 diabetes. Another path is to develop drugs that kill “senescent” cells that cause problems for healthy neighbours. But meanwhile groups of academic and commercial researchers are studying how to rejuvenate cells and tissues by altering the “epigenic” markers on chromosomes. Stripping back these markers – they accumulate with age – could create the cells of a 20-year old body in a person of 65.