準媽媽務必要多吃魚

Eating fish while you're pregnant does not increase the chance that your child will be autistic or have autistic traits, our latest study shows. In fact, our study suggests that fish may be beneficial for the development of a healthy nervous system.

我們最新的研究顯示，在懷孕期間食用魚肉并不會增加您的孩子罹患自閉癥的風險。事實上，研究表明魚類可能對神經(jīng)系統(tǒng)的發(fā)育健康有益。

A possible link between mercury exposure and autism has been the subject of much debate over the years. In pregnancy, mercury travels in the mother's blood through the placenta and into the foetus, where it acts as a toxin, affecting the development of the foetal nervous system.

汞與自閉癥之間可能存在的聯(lián)系多年來一直是爭論不休的話題。在懷孕期間，汞可以通過母親的血液滲入到胎盤中，進入胎兒循環(huán)系統(tǒng)，因其毒性影響到胎兒神經(jīng)系統(tǒng)的發(fā)育。

This has resulted in concern over two particular sources of mercury. First, fish is a source of mercury in the diet and there is concern that high fish consumption may cause damage to the developing nervous system.

這引發(fā)了人們對攝入汞的渠道來源的關注。首先，魚是通常食物中汞元素的主要來源，人們擔心大量食用魚肉可能會對發(fā)育中的神經(jīng)系統(tǒng)造成損害。

There is increasing evidence, however, that the beneficial effects of eating fish, probably through the nutrients it provides, outweigh the negative effects of the mercury it contains, even in people who eat a great deal of fish, such as the inhabitants of the Seychelles.

這引發(fā)了人們對攝入汞的渠道來源的關注。首先，魚是通常食物中汞元素的主要來源，人們擔心大量食用魚肉可能會對發(fā)育中的神經(jīng)系統(tǒng)造成損害。

Second, the use of thiomersal, a mercury-based preservative that is used in some vaccines, has created fears in some that immunisations might cause harm.

這引發(fā)了人們對攝入汞的渠道來源的關注。首先，魚是通常食物中汞元素的主要來源，人們擔心大量食用魚肉可能會對發(fā)育中的神經(jīng)系統(tǒng)造成損害。

Specifically, some people fear that vaccines containing thiomersal might be a cause of autism.

具體點說，有些人擔心含有硫柳汞的疫苗可能是導致自閉癥的原因。

Reviews of studies on this have reduced the concern over vaccines, and, in the EU at least, thiomersal is no longer used in childhood vaccinations.

對此問題的爭論甚至超過了公眾對疫苗本身的關注，并且至少在歐盟，硫柳汞不再用做兒童疫苗的防腐劑。

What's more, the amount of mercury in thiomersal is very small compared with the amount absorbed from the atmosphere and from the diet. Still, the fear that mercury is linked to autism persists.

更重要的是，硫柳汞中的汞含量比大氣和飲食中的所含有的汞元素還要少。不過，始終難以消去“汞引發(fā)自閉癥”這樣的疑慮。

Worse off without fish

不接種疫苗，如果還不吃魚的話，事情就變得更糟了。

With these concerns in mind, we have carried out a study to look at the link between mercury levels and fish consumption in pregnant women, together with autistic traits and diagnosed autism in their children, up to the age of nine years.

考慮到這些問題，我們開展了一項研究，希望確認孕婦血液中汞水平和魚類消費量之間的關系，以及這兩者與9歲之前呈現(xiàn)出自閉癥特征和經(jīng)過確診為自閉癥的兒童之間的關系。

The data were collected as part of the Children of the 90s Study (Avon Longitudinal Study of Parents and Children), which is based in Bristol, England.

原始數(shù)據(jù)是作為90年代一項兒童研究(父母和兒童的方差分析縱向研究)的一部分被收集起來的。對象來自英國的布里斯托爾。

We found that, although the mother's blood mercury level was higher if she ate more fish, there was no evidence that having a higher level of mercury meant that her child was more likely to be autistic or have autistic traits.

我們發(fā)現(xiàn)，如果母親吃了很多的魚，那么盡管她的血液汞含量比較高，也沒有證據(jù)表明她的孩子以后更可能罹患自閉癥或確實患有了自閉癥。

In fact, the score for one particular autistic trait, social cognition (for example, not being aware of other people's feelings), was likely to be worse in the child if the mother had not eaten fish in pregnancy.

事實上，如果母親在懷孕期間拒絕吃魚，那么某項單一自閉癥特征——社會認知缺失(例如，不知道其他人的感受)程度反而會加劇。

Clearer guidelines

明確的指導意見

National guidelines in the UK, and in many other countries, recommend that pregnant women eat at least two portions of fish per week, with one of them being an oily fish.

英國和其他許多國家的衛(wèi)生指南建議孕婦每周至少食用兩次魚肉，其中至少有一條是富含脂肪的魚。

Our study, and other people's studies, back this recommendation. As we have previously argued this recommendation needs to be made more prominent, and the guidelines need to be made clearer and simpler.

我們的研究和其他人的研究均支持這一建議。正如我們以前所說的，最好把這項建議用黑體加粗，貼在準媽媽的床頭。

Caroline Taylor, Research Fellow, University of Bristol.

作者 Caroline Taylor，布里斯托大學研究員。