时差N小时 吃甜食蛀牙怎么办?

It's time to go again to the A Moment of Science mailbag.

又到了科学时刻读信时间。

A listener writes in: Dear A Moment of Science, I love to eat sweets--candy, cookies, caramel apples--- everything. But I don't like getting cavities. Is there a way to eat lots of sugar without ruining your teeth?

一位听众写信说：亲爱的科学时刻栏目组，我爱吃所有的甜食，糖果，饼干，焦糖苹果等等。但是我讨厌蛀牙。有没有一种方法能让我既吃许多甜食又不蛀牙呢？

Interesting question. First, let's assume that you're not going to cut out sweets entirely¹. So what are your options? If you're going to eat candy, for example, it's best to eat a bunch all at once instead of eating a few pieces at a time throughout the day.

这个问题很有趣。首先，我们假设你不准备彻底戒食甜品。所以你会选择怎么做？假设你要吃糖果，最好是一下子吃完，而不是每次只吃一两块，每天吃几次。

That's because every time you eat sugar, or any carbohydrate² like potato chips or crackers³ or whatever, there's a thirty- to sixty-minute period where bacteria in your mouth feed on the carbs and produce acid. The acid is what eats away at your teeth. So if you're snacking on candy several times a day instead of just once, your teeth are exposed to more cavity-causing acid.

这是因为每次你吃糖或者其它含糖高的食物时，比如薯条或者薄脆饼干，有30至60分钟牙齿里细菌吸收糖分，并生成酸性物质。这些酸性物质会腐蚀你的牙齿。所以如果你一天吃几次糖果，那么牙齿就会接触到更多酸性物质，从而导致蛀牙。

It's also smart to eat candy around or just after mealtimes, because during meals you have an increased flow of saliva⁴ that helps wash out your mouth and creates a kind of buffer⁵ between your teeth and the bacterial⁶ acid.

饭前饭后吃糖果也是明智的选择，因为进餐时口内分泌的唾液增多，以帮助清洁口腔，同时也会在牙齿和细菌分泌的酸性物质之间生成一种酸碱缓冲液。

Your best bet, of course, is to lay off the candy. But of course that's easier said than done.

当然，最好的方法就是远离糖果。不过人总是说起来容易做起来难。

1 entirely   

ad.全部地，完整地；完全地，彻底地

参考例句：

• The fire was entirely caused by their neglect of duty. 那场火灾完全是由于他们失职而引起的。
• His life was entirely given up to the educational work. 他的一生统统献给了教育工作。

2 carbohydrate   

n.碳水化合物；糖类；(plural)淀粉质或糖类

参考例句：

• You should not have too much carbohydrate in your diet.你日常饮食中不该有过多碳水化合物。
• Cashew nuts are rich in carbohydrate.腰果含丰富碳水化合物。

3 crackers   

adj.精神错乱的，癫狂的n.爆竹( cracker的名词复数 )；薄脆饼干；（认为）十分愉快的事；迷人的姑娘

参考例句：

• That noise is driving me crackers. 那噪声闹得我简直要疯了。
• We served some crackers and cheese as an appetiser. 我们上了些饼干和奶酪作为开胃品。 来自《简明英汉词典》

4 saliva   

n.唾液，口水

参考例句：

• He wiped a dribble of saliva from his chin.他擦掉了下巴上的几滴口水。
• Saliva dribbled from the baby's mouth.唾液从婴儿的嘴里流了出来。

5 buffer   

n.起缓冲作用的人(或物)，缓冲器；vt.缓冲

参考例句：

• A little money can be a useful buffer in time of need.在急需时，很少一点钱就能解燃眉之急。
• Romantic love will buffer you against life's hardships.浪漫的爱会减轻生活的艰辛。

6 bacterial   

a.细菌的

参考例句：

• Bacterial reproduction is accelerated in weightless space. 在失重的空间，细菌繁殖加快了。
• Brain lesions can be caused by bacterial infections. 大脑损伤可能由细菌感染引起。