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  • When a team of archaeologists recently came across

    一支考古學者團隊最近意外碰到

  • 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

When a team of archaeologists recently came across

一支考古學者團隊最近意外碰到

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B2 中高級 中文 美國腔 TED-Ed 蛀牙 牙齒 細菌 微生物 人類

【TED-Ed】為什麼會有蛀牙?(What causes cavities? - Mel Rosenberg)

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    Lê Phước Đức 發佈於 2016 年 10 月 21 日
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