(单词翻译:单击)
听力文本
From VOA Learning English, this is the Health Report in Special English.
A new study found that women who took folic acid supplements in early pregnancy were less likely to have a child with autism. Folic acid is a B vitamin that helps the body build and repair cells. The study did not prove that folic acid can prevent childhood autism, but the findings suggest a connection. The researchers called for examining whether folic acid is associated with a reduced risk of other brain disorders in children.
Children with autism have problems communicating and socializing with other people.
A woman holds her stomach during the last stages of her pregnancy in Bordeaux, France, April 28, 2010.
Researchers at the Norwegian Institute of Public Health looked at records of more 85,000 children born between 2002 and 2008.
The study asked mothers to describe their diets, including vitamins and other nutritional treatments, before and during their pregnancies.
Research leader Pal Suren and his colleagues compared the women who took folic acid supplements to those who did not.
"The women who took folic acid supplements in early pregnancy had a substantial reduction in risk of having a child with autism. The reduction was 40 percent."
He says the best time to take folic acid to reduce the risk of autism seems to be from four weeks before to eight weeks after the start of pregnancy. The researchers found that taking folic acid halfway through pregnancy had no effect.
After the babies were born, investigators followed up with the children through the end of March 2012. They wanted to find out how many developed any form of autism. Two hundred seventy of the children had some form of autism. The study found no reduction in the risk of some forms of autism. But it did find a lower risk for the most severe form. There were not enough children with a milder form known as Asperger's syndrome to make any findings.
The cause of autism is not known, but several genes may play a part.
Folic acid has been linked to the development of a protective covering called the neural tube in a fetus. Women who do not get enough folic acid are at risk of giving birth to infants with part of their spinal cord or brain exposed. This disabling condition is called spina bifida.
Ezra Susser of Columbia University in New York City was a co-author of the new study of folic acid.
"These supplements are already recommended for other reasons. So this increases the reasons why we should recommend them."
Dark leafy vegetables, asparagus, broccoli and citrus fruit are rich sources of folate. Folate is the naturally occurring form of folic acid. Folate is also found in peas, lentils, beans, eggs, yeast and liver.
Studies have shown that many pregnant women get less folate in their diet than they need to prevent neural tube defects. So folic acid supplements are commonly recommended for pregnant women. Some countries add folic acid to flour. Norway does not do that.
The study appears in the Journal of the American Medical Association.
词汇解释
1.folic acid 叶酸，维生素B
Iron, folic acid and protein are also important at this stage of development.
铁、叶酸和蛋白质在发展的这个阶段也是很重要的。
2.autism n. [心理][内科] 孤独症；自我中心主义
She said it added to the understanding of autism.
她说这增加了人们对自闭症的理解。
3.spinal cord 脊髓
Neurosyphilis: is an infection of the brain or spinal cord.
神经性梅毒是一种脑部或脊髓感染。
参考译文
这里是美国之音慢速英语健康报道。
一项最新研究发现，在怀孕早期服用叶酸的孕妇生下的孩子患有孤独症的几率更小。叶酸是一种维生素B，能帮助身体发育和修复细胞。这项研究未能证明叶酸可以预防儿童孤独症，但发现结果表明两者存在关联。研究者呼吁进行调查，看叶酸是否能减少儿童患上其他大脑疾病的风险。
患有孤独症的儿童存在沟通与社交障碍。
挪威国家公共卫生研究院的研究者查看了8.5万名生于2002到2008年的儿童。
他们向母亲们调查怀孕前后的饮食、维生素和其他营养疗法。
研究负责人Pal Suren和同事对比了服用叶酸补充剂和没有服用的妇女。
“在怀孕早期服用叶酸的孕妇生下的孩子患有孤独症的几率更小，能降低40%的发病率。”
他说，为降低孤独症的几率，服用叶酸的最佳时间是怀孕后第四周到第八周之间。研究者发现在孕期中间服用叶酸没有效果。
婴儿出生后，调查者一直跟进研究到2012年3月，他们想了解到底多少孩子患上孤独症。有270名儿童患上某种形式的孤独症，研究发现某些孤独症的发病风险没有降低。但最严重的那些类型确实降低了，同时，也没有足够数量的儿童患上中度艾斯伯格综合症来进行研究。
孤独症的发病原因尚未知，但几种基因会起到作用。
叶酸与胎儿体内名为神经管的保护层的形成有关，那些服用叶酸不充足的孕妇，其产下的婴儿可能有部分脊柱外露，这种疾病叫脊柱裂。
纽约哥伦比亚大学的Ezra Susser是这份有关叶酸研究的合作者。
“我们推荐服用叶酸还有其他原因，因此更应该推荐使用。”
绿叶蔬菜、芦笋、花椰菜和橘子都富含叶酸，还是自然形式的叶酸。豌豆、扁豆、蚕豆、鸡蛋、酵母和肝脏里都含有叶酸。
研究还发现，许多孕妇饮食中含有的叶酸不足以预防神经管缺损，因此，我们强烈建议孕妇服用叶酸补充剂，有的国家在面粉里加入叶酸，而挪威就没有这么做。
这份研究发表在《美国医学协会》杂志上。
