From Peter Hajek, London, UK
I enjoyed looking at your choice of the best ideas of the 21st century. I would like to add two major breakthroughs that were missing from the list. The 21st century has seen the first steps to replace, on the population level, the deadly vehicle of nicotine delivery – cigarettes – with those that pose only a small fraction of the health risks of smoking, such as e-cigarettes, heated tobacco products and nicotine pouches (24 January, p 30).
Regarding obesity, the discovery of the effects of agonists of gut hormones has already been translated into large-scale treatments that will eventually generate population-level impact. Both of these ideas, and the products they generated, continue to develop and progress. Smoking- and obesity-related disease and death may well disappear during this century.
