What causes cavities? - Mel Rosenberg

譯者: Helen Chang 審譯者: Ting-Chih Liang

When a team of archaeologists recently came across

近期有個考古團隊

some 15,000 year-old human remains,

找到了大約一萬五千歲的人類遺骸

they made an interesting discovery.

他們有個饒富興味的發現

The teeth of those ancient humans were riddled with holes.

那些古代人的牙齒上，有許多坑洞

Their cavities were caused by the same thing that still plagues us today,

這些蛀洞的成因

和今日仍然困擾我們的蛀牙一樣

specific tiny microbes that live in our mouths.

是由口腔裡的特定微生物所引起的

在我們出生後不久 這些微生物就已與我們同在

These microbes are with us soon after birth.

We typically pick them up as babies from our mothers' mouths.

通常是從母親的嘴傳給嬰兒

我們長出牙齒後

And as our teeth erupt,

they naturally begin to accumulate communities of bacteria.

自然地累積而成細菌的聚落

Depending on what we eat,

根據我們所吃的東西

and specifically how much sugar we consume,

特別是糖的數量

certain microbes can overpopulate and cause cavities.

某些微生物會過度孳長而導致蛀牙

Diets high in sugary foods cause an explosion of bacteria

吃了高度含糖的食物

會導致口腔裡的 「轉糖鏈球菌」爆炸性孳生

called mutans streptococci in our mouths.

Like humans, these microorganisms love sugar,

這些微生物和人類一樣喜愛糖

using it as a molecular building block and energy source.

用糖組成分子結構 並當作能量的來源

當微生物消耗糖分時

As they consume it,

the bacteria generate byproducts in the form of acids,

細菌產生酸性的副產物

such as lactic acid.

例如「乳酸」

Mutans streptococci are resistant to this acid,

轉糖鏈球菌並不怕酸

but unfortunately, our teeth aren't.

但很不幸的，我們的牙齒怕酸

While each human tooth is coated in a hardy, protective layer of enamel,

雖然人類的牙齒有一層 堅硬的「琺瑯質」保護層

it's no match for acid.

但敵不過酸

That degrades the armor over time, leaching away its calcium minerals.

隨著時間經過，鈣質礦物被溶解 使得琺瑯質保護層愈來愈薄

Gradually, acid wears down a pathway for bacteria

漸漸地，酸蝕穿了一條通道

into the tooth's secondary layer called the dentin.

細菌進入被稱為 「牙本質」的牙齒內層

Since blood vessels and nerves in our teeth are enclosed deep within,

因為血管和神經 埋在封閉的牙齒深處

at this stage, the expanding cavity doesn't hurt.

在此階段，逐漸擴大的 蛀牙區並不會產生疼痛

But if the damage extends beyond the dentin,

但若損害擴大 超出了牙本質的範圍

the bacterial invasion progresses

持續侵入的細菌

causing excruciating pain as the nerves become exposed.

一旦碰到了神經 就會引起劇烈疼痛

Without treatment, the whole tooth may become infected

如不進行治療 整個牙齒會受到感染

and require removal

甚至需要被拔除

all due to those sugar-loving bacteria.

這全都是愛糖的細菌所導致的

The more sugar our food contains,

食物含糖越多

the more our teeth are put at risk.

牙齒就越危險

Those cavemen would hardly have indulged in sugary treats, however,

然而，那些穴居人 應該很難沉溺於美味的糖

so what caused their cavities?

是什麼引起他們的蛀牙呢？

In meat-heavy diets, there would have been a low-risk of cavities developing

偏重肉類的飲食，蛀牙的風險很低

because lean meat contains very little sugar,

因為瘦肉含糖分極少

but that's not all our early human ancestors ate.

但人類的祖先不僅吃肉

Cavemen would also have consumed root vegetables, nuts, and grains,

穴居人也吃根莖類蔬菜 堅果和穀物

all of which contain carbohydrates.

這些全都含有醣類（碳水化合物）

When exposed to enzymes in the saliva,

當醣類遇到唾液中的酶時

carbohydrates get broken down into simpler sugars,

碳水化合物被分解成較簡單的糖

which can become the fodder for those ravenous mouth bacteria.

成為那些嘴饞的口腔細菌的飼料

So while ancient humans did eat less sugar compared to us,

雖然古人吃的糖確實比我們少

their teeth were still exposed to sugars.

他們的牙齒仍然暴露在糖分中

That doesn't mean they were unable to treat their cavities, though.

雖然如此，並不意味著 他們無法治療蛀牙

Archaeological remains show that about 14,000 years ago,

考古遺跡顯示，大約一萬四千年前

humans were already using sharpened flint to remove bits of rotten teeth.

人類已用磨尖的燧石去除爛牙

Ancient humans even made rudimentary drills

古代人甚至做出了簡易的牙鑽

to smooth out the rough holes left behind

用來磨平粗糙的蛀孔

and beeswax to plug cavities, like modern-day fillings.

並且使用蜂蠟來填塞蛀洞 就像現代的填料

Today, we have much more sophisticated techniques and tools,

很幸運的，今天 我們有更成熟的技術和工具

which is fortunate because we also need to contend with our more damaging,

因為我們需要面臨更具破壞性的

sugar-guzzling ways.

嗜吃糖分的飲食方式

After the Industrial Revolution, the human incidence of cavities surged

工業革命後，人類的蛀牙率激增

because suddenly we had technological advances

因為技術的突飛猛進

that made refined sugar cheaper and accessible.

使得精製糖更為便宜，容易獲得

Today, an incredible 92% of American adults have had cavities in their teeth.

你可能會難以置信 目前有 92％ 的美國成年人有蛀牙

有些人容易蛀牙

Some people are more susceptible to cavities due to genes

that may cause certain weaknesses, like softer enamel,

是因為基因所導致的琺瑯質脆弱

but for most, high sugar consumption is to blame.

但大多數人則是 因為吃了太多糖而蛀牙

However, we have developed other ways of minimizing cavities

儘管如此，我們已發展出 減少齲齒的各種方法

besides reducing our intake of sugar and starch.

除了降低糖和澱粉的攝取量

In most toothpastes and many water supplies,

在大多數的牙膏和飲用水中

we use tiny amounts of fluoride.

也添加了微量的氟化物

That strengthens teeth and encourages the growth of enamel crystals

可以強化牙齒、促進琺瑯質的生長

that build up a tooth's defenses against acid.

建立牙齒抗酸的防禦力

When cavities do develop,

一旦發生蛀牙

we use tooth fillings to fill and close off the infected area,

我們填補、密封牙齒的感染區

preventing them from getting worse.

防止它繼續惡化

The best way to avoid a cavity is still cutting down on sugar intake

避免蛀牙的最佳辦法 仍然是減少糖分的攝取

and practicing good oral hygiene

並保持良好的口腔衛生

to get rid of the bacteria and their food sources.

以去除細菌和他們的食物來源

That includes regular tooth brushing,

這包括定期地刷牙

flossing,

使用牙線

and avoiding sugary,

避開含糖、澱粉食物

starchy,

and sticky foods that cling to your teeth between meals.

還有那些會在兩餐之間 附著於牙齒的粘性食物

Gradually, the population of sugar-loving microbes in your mouth will decline.

如此，口中的嗜糖微生物數量

就會逐漸減少

Unlike the cavemen of yesteryear,

和以前的穴居人不一樣

today we have the knowledge required to avert a cavity calamity.

今天我們有避免蛀牙所需的知識

We just need to use it.

我們只需實踐它