《美国营养学院杂志》2004年12月研究：依据美国农业部1950年到1999年43种不同的蔬菜与水果的营养资料，发现蛋白质、钙、磷、铁、核黄素（维生素B2）与维生素C过去半世纪以来“可靠性下降”。这种营养含量下降的趋势归于旨在提高性状（规模、增长率、害虫抵抗力）而不是营养的农业实践。库什研究所对1975年到1997年营养资料的分析发现12种新鲜蔬菜的平均含钙量减少27%；铁减少37%；维生素A减少21%，维生素C减少30%。《英国食物杂志》对英国1930年到1980年期间营养成分资料进行的类似研究，发现20种蔬菜中平均钙含量下降了19%；铁下降了22%；磷下降了14%。另外一项研究结论，现在要吃八只橘子才能获得我们的祖辈吃一只橘子含的同样多维生素A。苹果也已丧失其80%的维生素C。怎么办？有机生态农业是恢复健康土壤唯一出路！   

Dirt Poor: Have Fruits and Vegetables Become Less Nutritious?

土壤枯竭：水果与蔬菜变得更加少营养？

转载、翻译者：陈一文（cheniwan@cei.gov.cn ）

中国灾害防御协会灾害史专业委员会顾问

《转基因技术与人类安全》研究者、80年代前全国青联委员

转载自《科学美国人》网站

http://www.scientificamerican.com/article/soil-depletion-and-nutrition-loss/

Because of soil depletion, crops grown decades ago were much richer in vitamins and minerals than the varieties most of us get today

由于土壤枯竭，几十年前种植的作物在维生素与矿物质方面比现在大部分作物更加丰富。

Martin Poole, Digital Vision/Thinkstock

Dear Earth Talk: What’s the nutritional difference between the carrot I ate in 1970 and one I eat today? I’ve heard that that there’s very little nutrition left. Is that true?—Esther G., Newark, N.J.

《亲爱的地球》谈话节目：70年代末与我们今天吃的胡萝卜之间的营养差别有多大？我听说现在的胡萝卜只剩下很少营养。这是真的吗？-- 新泽西听众

It would be overkill to say that the carrot you eat today has very little nutrition in it—especially compared to some of the other less healthy foods you likely also eat—but it is true that fruits and vegetables grown decades ago were much richer in vitamins and minerals than the varieties most of us get today.

说你现在吃的胡萝卜只剩下很少营养，这样说过份 -- 特别如果与你可能吃的其他某些更不健康的食物相比 -- 但是，几十年前种植的水果与蔬菜与我们今天得到的大部分品种相比在维生素与矿物质方面丰富的多。

The main culprit in this disturbing nutritional trend is soil depletion: Modern intensive agricultural methods have stripped increasing amounts of nutrients from the soil in which the food we eat grows. Sadly, each successive generation of fast-growing, pest-resistant carrot is truly less good for you than the one before.

造成这种令人不安营养性趋势的罪魁祸首是土壤枯竭：现代现代大规模集约化农业的方法耗尽了我们吃的食物生长的土壤中越来越多的营养物质。令人痛心的是，一代又一代快速种植的抗虫胡萝卜确实比前一年种植的营养更少。

A landmark study on the topic by Donald Davis and his team of researchers from the University of Texas (UT) at Austin’s Department of Chemistry and Biochemistry was published in December 2004 in the Journal of the American College of Nutrition.

《美国营养学院杂志》2004年12月发表了多纳尔德·戴维斯及其特克萨斯大学奥斯丁化学与生物化学部的研究团队对于这个课题具有里程碑意义的研究。

They studied U.S. Department of Agriculture nutritional data from both 1950 and 1999 for 43 different vegetables and fruits, finding “reliable declines” in the amount of protein, calcium, phosphorus, iron, riboflavin (vitamin B2) and vitamin C over the past half century. Davis and his colleagues chalk up this declining nutritional content to the preponderance of agricultural practices designed to improve traits (size, growth rate, pest resistance) other than nutrition.

他们研究了美国农业部1950年到1999年43种不同的蔬菜与水果的营养资料，发现蛋白质、钙、磷、铁、核黄素（维生素B2）与维生素C过去半世纪以来“可靠性下降”。戴维斯及其同事们将这种营养含量下降的趋势归于旨在提高性状（规模、增长率、害虫抵抗力）而不是营养的农业实践。

“Efforts to breed new varieties of crops that provide greater yield, pest resistance and climate adaptability have allowed crops to grow bigger and more rapidly,” reported Davis, “but their ability to manufacture or uptake nutrients has not kept pace with their rapid growth.”

“努力培育提供更高产量、抗虫能力与气候适应性的作物品种允许农作物长的更大与更快”，戴维斯报告，“但是这些农作物制造或者摄取营养的能力未能跟上它们迅速的生长。”

There have likely been declines in other nutrients, too, he said, such as magnesium, zinc and vitamins B-6 and E, but they were not studied in 1950 and more research is needed to find out how much less we are getting of these key vitamins and minerals.

蔬菜与水果中其他营养成分也可能下降，他说，如镁、锌与维生素B-6与E，但是1950年期间对它们没有进行研究，需要进行更多研究来发现我们减少了多少这些关键性的维生素与矿物质。

The Organic Consumers Association cites several other studies with similar findings: A Kushi Institute analysis of nutrient data from 1975 to 1997 found that average calcium levels in 12 fresh vegetables dropped 27 percent; iron levels 37 percent; vitamin A levels 21 percent, and vitamin C levels 30 percent.

《有机消费者协会》引用了类似发现的数项其他研究：库什研究所对1975年到1997年营养资料的分析发现12种新鲜蔬菜的平均含钙量减少27%；铁减少37%；维生素A减少21%，维生素C减少30%。

A similar study of British nutrient data from 1930 to 1980, published in the British Food Journal, found that in 20 vegetables the average calcium content had declined 19 percent; iron 22 percent; and potassium 14 percent. Yet another study concluded that one would have to eat eight oranges today to derive the same amount of Vitamin A as our grandparents would have gotten from one.

《英国食物杂志》发表对英国1930年到1980年期间营养成分资料进行的类似研究，发现20种蔬菜中平均钙含量下降了19%；铁下降了22%；磷下降了14%。另外一项研究结论，现在要吃八只橘子才能获得我们的祖辈吃一只橘子含的同样多维生素A。

What can be done? The key to healthier produce is healthier soil. Alternating fields between growing seasons to give land time to restore would be one important step. Also, foregoing pesticides and fertilizers in favor of organic growing methods is good for the soil, the produce and its consumers. Those who want to get the most nutritious fruits and vegetables should buy regularly from local organic farmers.

怎么办？生产更加健康食物的关键是更加健康的土壤。不同生长季节之间轮流种植不同的土地，给土地恢复生机的时间是重要的一步。此外，采用有益与有机种植方法的农药与肥料对土壤、生产及其消费者有益。希望获得最为营养性水果与蔬菜的人士应当定期购买当地有机农场的产品。

UT’s Davis warns that just because fruits and vegetables aren’t as healthy as they used to be doesn’t mean we should avoid them. “Vegetables are extraordinarily rich in nutrients and beneficial phytochemicals,” he reported. “They are still there, and vegetables and fruits are our best sources for these.”