经济学人下载:农业与营养,隐性饥饿

Of the 40 nutrients people need, four are in chronically short supply: iron, zinc, iodine and vitamin A. Vitamin A is essential for the mucous membranes that protect the body’s organs, such as the eyes. Lack of it causes half a million children to go blind every year; half of them die within a year as their other organs fail. Vitamin A supplements were the Copenhagen experts’ top choice. Zinc deficiency impairs brain and motor functions and causes roughly 400,000 deaths a year. Shortage of iron (anaemia) weakens the immune system and affects, in some poor countries, half of all women of child-bearing age.

在人体所需的40种营养元素中，有4种长期匮乏：铁、锌、碘和维A。维A对保护人体器官粘膜至关重要，比如眼睛。维A的缺乏每年导致近50万儿童失明，其中一半的儿童因其他身体器官衰竭而死亡。补充维A是哥本哈根的经济学家最优先的选择。缺锌对大脑与运动神经功能有害，每年近40万人因缺锌死亡。缺铁（贫血症）致使免疫力下降，在一些贫困国家，到达生育年龄的妇女中有一半都有缺铁性贫血。

Too hungry to think properly饿得无法集中精神
The missing nutrients bite wide and deep. Education levels drop (malnourished children concentrate poorly); earning-power weakens. Even marriage chances wane: malnourished boys marry women of lower educational levels when they grow up.

缺乏营养对人体危害很大，导致教育水平下降（营养不良的儿童注意力无法集中）以及收入能力降低。甚至婚姻也因此走下坡路：营养不良的男性长大后会娶教育水平较低的女性为伴。

Common responses include handing out vitamin pills and fortifying common foods with micronutrients (such as putting iodine in salt). But policymakers are now asking whether farming could do more to improve nutrition. That was the subject of a recent conference in Delhi organised by the International Food Policy Research Institute and attended by 1,000-odd politicians, scientists and activists.

普通的解决方法包括发放维生素片以及向日常食物中添加微量营养元素（如食盐加碘）。但政策制定者们现在提出的问题是农业是否能够更好地促进营养。这个问题也是近期由国际粮食政策研究所在德里召开的会议的主题，与会者包括1000余位政客、科学家与社会活动家。

Farming ought to be especially good for nutrition. If farmers provide a varied diet to local markets, people seem more likely to eat well. Agricultural growth is one of the best ways to generate income for the poorest, who need the most help buying nutritious food. And in many countries women do most of the farm work. They also have most influence on children’s health. Profitable farming, women’s income and child nutrition should therefore go together. In theory a rise in farm output should boost nutrition by more than a comparable rise in general economic well-being, measured by GDP.

农业理应增进营养。如果农户能够像当地市场提供多样化的食品，人们便能有更健康的饮食。贫穷人群最需要获得帮助，购买有营养的食品，而农业发展则是增加贫穷人群收入的最好方式之一。在许多国家，务农的主要是女性，她们对儿童的健康也有着很大的影响。因此，可盈利性务农、女性收入以及儿童营养应该齐头并进。从理论上讲，农业产出增加比相应比例的总体经济增长（如GDP的增加）要更有利于促进营养。

In practice it is another story. A paper* written for the Delhi meeting shows that an increase in agricultural value-added per worker from $200 to $500 a year is associated with a fall in the share of the undernourished population from about 35% to just over 20%. That is not bad. But it is no better than what happens when GDP per head grows by the same amount. So agriculture seems no better at cutting malnutrition than growth in general.

而现实中则完全不同。德里会议上的一篇论文指出，每位工人每年的农业增值200到500美元将使得营养不良人群比例从35%降低到20%。这已经是个很明显的进步了。然而，这还是不及同比例的人均GDP增长所带来的效果明显。因此，在减少营养不良方面，农业似乎不如总体经济增长起作用。