A taller world

014_Tecnociencia_02_247_altaDANIEL BUENOWorldwide, human populations have grown a few centimeters taller over the past century, according to a major survey that compiled information on the stature of 18.6 million people born between 1896 and 1996.  Researchers from the international network of health scientists known as NCD Risk Factor Collaboration, which includes some Brazilian groups, surveyed 1,472 scientific papers to collect data on the height of people of 200 nationalities and found that this increase varied sharply from one population to another. Overall, male height grew 1 cm to 15 cm during this period, while female height increased by 2 cm to 20 cm (eLife, July 2016). Dutch men are currently the tallest on the planet, averaging 1.83 meters. The shortest are from East Timor, at 1.60 meters. The tallest females are from Latvia, with an average height of 1.70 meters, while the shortest are from Guatemala, where they measure just under 1.50 meters. The biggest gains during this 100-year period were made by South Korean women, who are now 20.2 cm taller, and Iranian men, who gained 16.5 cm. Brazilian men and women are roughly 10 cm taller and now average about 1.70 and 1.60 meters, respectively. The overall increase in stature is attributed to improved living conditions. Although a population’s genetic traits influence individual height, research suggests that these differences stem from nutrition during pregnancy, childhood, and adolescence. Some studies also suggest that taller people live longer and have a lower risk of developing cardiovascular and respiratory disease. Other studies also indicate that they reach higher educational levels and earn better pay. People in Sub-Saharan Africa and southern Asia grew the least – some even shrunk – possibly as a result of declining living conditions in recent decades.