People have grown taller over the last century, with South Korean women shooting up by more than 20cm on average, and Iranian men gaining 16.5cm. A global study looked at the average height of 18-year-olds in 200 countries between 1914 and 2014.
The results reveal that while Swedes were the tallest people in the world in 1914, Dutch men have risen from 12th place to claim top spot with an average height of 182.5cm. Latvian women, meanwhile, rose from 28th place in 1914 to become the tallest in the world a century later, with an average height of 169.8cm.
James Bentham, a co-author of the research from Imperial College, London, says the global trend is likely to be due primarily to improvements in nutrition and healthcare. "An individual's genetics has a big influence on their height, but once you average over whole populations, genetics plays e less key role," he added.
A little extra height brings a number of advantages, says Elio Riboli of Imperial College. "Being taller is associated with longer life expectancy," he said. "This is largely due to a lower risk of dying of cardiovascular (心血管的）disease among taller people."
But while height has increased around the world, the trend in many countries of north and sub-Saharan Africa causes concern, says Riboli. While height increased in Uganda and Niger during the early 20th century, the trend has reversed in recent years, with height decreasing among 18-year-olds.
"One reason for these decreases in height is the economic situation in the 1980s," said Alexander Moradi of the University of Sussex. The nutritional and health crises that followed the policy of structural adjustment, he says, led to many children and teenagers failing to reach their full potential in terms of height.
Bentham believes the global trend of increasing height has important implications. "How tall we are now is strongly influenced by the environment we grew up in," he said. "If we give children the best possible start in life now, they will be healthier and more productive for decades to come."
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解析
上个世纪人们长高了，韩国女性平均身高增加了 20 厘米以上，伊朗男性增加了 16.5 厘米。一项全球研究调查了 1914 年至 2014 年间 200 个国家/地区 18 岁青少年的平均身高。
结果显示，虽然瑞典人在 1914 年是世界上最高的人，但荷兰男性已经从第 12 位上升到平均身高 182.5 厘米的榜首。与此同时，拉脱维亚女性从 1914 年的第 28 位上升到一个世纪后成为世界上最高的女性，平均身高为 169.8 厘米。
伦敦帝国理工学院研究的合著者 James Bentham 表示，全球趋势可能主要是由于营养和医疗保健的改善。“一个人的基因对他们的身高有很大的影响，但是一旦你对整个人群进行平均，基因的作用就不那么重要了，”他补充道。
帝国理工学院的 Elio Riboli 说，稍微高一点会带来很多好处。“更高与更长的预期寿命有关，”他说。“这主要是由于较高的人死于心血管（心血管）疾病的风险较低。”
Riboli 说，虽然世界各地的身高都在增加，但北非和撒哈拉以南非洲许多国家的这一趋势令人担忧。虽然 20 世纪初乌干达和尼日尔的身高有所增加，但近年来这一趋势发生了逆转，18 岁儿童的身高有所下降。
“身高下降的一个原因是 1980 年代的经济形势，”萨塞克斯大学的亚历山大莫拉迪说。他说，结构调整政策带来的营养和健康危机导致许多儿童和青少年未能在身高方面充分发挥潜力。
Bentham 认为，全球身高增长趋势具有重要意义。“我们现在的身高受到我们成长环境的强烈影响，”他说。“如果我们现在就给孩子们最好的人生开端，他们将在未来几十年变得更健康、更有效率。”
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