some 15,000 year-old human remains,

幾具15,000年前的人類遺體

they made an interesting discovery.

他們發現一件有趣的事

The teeth of those ancient humans were riddled with holes.

那些古人類的牙齒上滿是坑坑洞洞

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

引起他們的蛀牙的原因，到今天同樣困擾著我們

specific tiny microbes that live in our mouths.

特定微生物活在我們嘴巴裡頭

These microbes are with us soon after birth.

這些微生物在我們出生後不久就與我們朝夕相處

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

我們通常是在嬰兒時期，就從媽媽的嘴裡接收它們

And as our teeth erupt,

當我們開始長牙

they naturally begin to accumulate communities of bacteria.

他們很自然地開始積累細菌聚落

Depending on what we eat,

我們吃下去什麼

and specifically how much sugar we consume,

特別是我們吸收了多少糖份

certain microbes can overpopulate and cause cavities.

使得特定微生物數量大量爆發並引發蛀牙

Diets high in sugary foods cause an explosion of bacteria

大量的含糖食物會導致細菌大爆發

called mutans streptococci in our mouths.

稱為口腔變形鏈球菌

Like humans, these microorganisms love sugar,

像人類一樣，這些微生物超愛糖份

using it as a molecular building block and energy source.

用糖當作為分子構件和其能量來源

As they consume it,

當他們消化糖份時，

the bacteria generate byproducts in the form of acids,

這些細菌會產生以酸形式出現的副產品

such as lactic acid.

像是乳酸

Mutans streptococci are resistant to this acid,

變形鏈球菌具有抗酸性

but unfortunately, our teeth aren't.

但很不幸的是，我們的牙齒並沒有

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

雖然每個人的牙齒都有一層堅硬、保護性的琺瑯質

it's no match for acid.

它卻無法抵抗酸

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

這層裝甲會隨著時間逐漸消解，被濾出其中的礦物質鈣

Gradually, acid wears down a pathway for bacteria

慢慢地，酸會為細菌蛀蝕出一條通路

into the tooth's secondary layer called the dentin.

進入牙齒的第二層的牙本質

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

由於牙齒中的血管和神經被封閉在深處，

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

在這個階段，逐漸擴張的蛀洞雖然不會痛

But if the damage extends beyond the dentin,

但如果損傷超過牙本質

the bacterial invasion progresses

細菌的侵入益深

causing excruciating pain as the nerves become exposed.

到神經的暴露時就會引發要命的疼痛

Without treatment, the whole tooth may become infected

如果不治療，整顆牙齒還可能受到感染

and require removal

並需要拔除

all due to those sugar-loving bacteria.

全都起因於那些愛吃糖的細菌

The more sugar our food contains,

我們食物含糖量越高

the more our teeth are put at risk.

牙齒的風險就越大

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

但是，那些穴居人幾乎不曾沉迷於含糖食物

so what caused their cavities?

那又是什麼造成蛀牙呢?

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

在重吃肉的飲食中，導致蛀牙的風險其實很低

because lean meat contains very little sugar,

因為瘦肉含糖份其實非常少

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

然而我們早期人類祖先並不是全部吃肉

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

穴居人也吃根莖蔬菜菜，堅果和穀物

all of which contain carbohydrates.

這些全都富含碳水化合物

When exposed to enzymes in the saliva,

當暴露於唾液中的酶時

carbohydrates get broken down into simpler sugars,

碳水化合物會分解成更簡單的糖

which can become the fodder for those ravenous mouth bacteria.

它就成為那些貪婪的口腔細菌的飼料

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

因此，儘管古人類比我們吃的糖要少很多

their teeth were still exposed to sugars.

他們的牙齒仍然暴露於糖份之中

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

但這也不代表他們就無法治療自己的蛀牙

Archaeological remains show that about 14,000 years ago,

考古遺跡顯示，大約14, 000年前

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

人類已經使用尖銳的燧石來拔除爛牙

Ancient humans even made rudimentary drills

古代人甚至會進行初步的鑽孔

to smooth out the rough holes left behind

以磨平牙齒上粗糙的孔洞

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

並且用蜂蠟填入蛀牙內，就像現代牙齒的填充物

Today, we have much more sophisticated techniques and tools,

今天，我們擁有更精細的技術和工具

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

說來幸運，但我們也需要與更多損害抗衡

sugar-guzzling ways.

亦即人類嗜糖的生活方式

After the Industrial Revolution, the human incidence of cavities surged

工業革命之後，人類的蛀牙數爆增

because suddenly we had technological advances

主因在於我們的技術大幅進步

that made refined sugar cheaper and accessible.

讓精製糖更加便宜和容易取得

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

今天，高達92％的美國成年人都有蛀牙。非常驚人

Some people are more susceptible to cavities due to genes

許多人因此更懷疑蛀牙是因基因所造成

that may cause certain weaknesses, like softer enamel,

導致現代人產生許多缺陷，像是牙齒上琺瑯質變軟

but for most, high sugar consumption is to blame.

但大部分，蛀牙應歸責於吃下高糖量

However, we have developed other ways of minimizing cavities

然而，我們已另外開發許多方法來減少蛀牙

besides reducing our intake of sugar and starch.

除了平常減少攝入的糖和澱粉之外

In most toothpastes and many water supplies,

像是在大多數的牙膏和許多水源當中

we use tiny amounts of fluoride.

填加少量的氟化物

That strengthens teeth and encourages the growth of enamel crystals

以強化牙齒，並刺激琺瑯質的生長

that build up a tooth's defenses against acid.

建立牙齒的抗酸性

When cavities do develop,

一旦開始有了蛀牙

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

我們則用填充物填充和封閉感染區域

preventing them from getting worse.

以防他們惡化

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

避免蛀牙的最好辦法，依舊是減少過量攝入糖份

and practicing good oral hygiene

並且保持好的口腔衛生習慣

to get rid of the bacteria and their food sources.

去除細菌和他們的食物來源

That includes regular tooth brushing,

這包括定期刷牙

flossing,

使用牙線

and avoiding sugary,

避免太多含糖

starchy,

澱粉

and sticky foods that cling to your teeth between meals.

以及三餐之間會粘在你牙齒上的粘稠食物

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

逐漸地，你嘴裡愛糖的微生物數量就會慢慢下降

Unlike the cavemen of yesteryear,

和以往穴居人不同

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

今天，我們已經擁有必備的知識，可以避免蛀牙的災難。

We just need to use it.

只要我們能夠運用它