How does alcohol make you drunk? - Judy Grisel

Translator: Reviewer: Thomas Tam

乙醇：分子係由幾個以上嘅碳原子組成

Ethanol: this molecule, made of little more than a few carbon atoms,

is responsible for drunkenness.

係造成醉酒嘅原因

Often simply referred to as alcohol,

簡單嚟講就係酒精

ethanol is the active ingredient in alcoholic beverages.

乙醇係酒精飲品中活性嘅成分

佢輕巧嘅分子偷偷穿過細胞薄膜

Its simplicity helps it sneak across membranes

and nestle into a many different nooks,

並停留喺好多唔同角落

producing a wide range of effects compared to other, clunkier molecules.

同其他笨重嘅分子相比 佢能夠產生更廣泛嘅影響

So how exactly does it cause drunkenness,

到底酒精係點樣導致醉酒

and why does it have dramatically different effects on different people?

為乜嘢佢對唔同人有非一樣嘅影響呢？

To answer these questions,

要解開呢個啞謎

we’ll need to follow alcohol on its journey through the body.

我哋需要跟酒精喺身體走一轉

Alcohol lands in the stomach and is absorbed into the blood

酒精通過消化系統，落到胃

through the digestive tract, especially the small intestine.

尤其係小腸使到血液吸收

The contents of the stomach impact alcohol’s ability

食物喺胃度影響酒精進入血液

to get into the blood because after eating, the pyloric sphincter,

因為進食後幽門括約肌關閉

將胃同小腸分隔

which separates the stomach from the small intestine, closes.

So the level of alcohol that reaches the blood after a big meal

所以飲同樣嘅酒，血液嘅酒精水平

might only be a quarter that from the same drink on an empty stomach.

喺食飽後只有空肚嘅四分一

From the blood, alcohol goes to the organs,

酒精靠血液流動進入器官

especially those that get the most blood flow:

尤其係要最多血液嘅器官：

the liver and the brain.

肝臟同大腦

It hits the liver first, and enzymes in the liver

佢首先侵襲肝臟

break down the alcohol molecule in two steps.

肝度啲酶，分兩個步驟分解酒精分子

First, an enzyme called ADH turns alcohol into acetaldehyde, which is toxic.

首先係種叫做乙醇脱氫酶（ADH） 將酒精轉化為有毒嘅乙醛

Then, an enzyme called ALDH converts the toxic acetaldehyde to non-toxic acetate.

然後一種叫乙醇脱氫酶（ALDH） 將有毒嘅乙醛轉化為無毒嘅醋酸鹽

As the blood circulates, the liver eliminates alcohol continuously—

隨著血液循環，肝臟不斷排除酒精——

but this first pass of elimination determines how much alcohol

但喺第一次排除，就決定咗有幾多酒精

reaches the brain and other organs.

去到大腦同其他器官

Brain sensitivity is responsible for the emotional, cognitive,

酒精影響大腦對情緒、認知

and behavioral effects of alcohol— otherwise known as drunkenness.

行為嘅敏感性——亦叫做醉酒

Alcohol turns up the brain’s primary brake, the neurotransmitter GABA,

酒精打開咗神經遞質 γ-氨基丁酸 大腦嘅主要煞掣

and turns down its primary gas, the neurotransmitter glutamate.

並拒絕佢嘅主要氣體 即神經遞質谷氨酸

大大降低咗神經元嘅溝通能力

This makes neurons much less communicative,

and users feel relaxed at moderate doses, fall asleep at higher doses,

而人飲適量嘅酒，會感到放鬆 但較多嘅酒就會入睡

and can impede the brain activity necessary for survival at toxic doses.

同時防礙咗大腦作為生存 要應對毒素劑量嘅活動

Alcohol also stimulates a small group of neurons

酒精也會刺激小部分神經元

that extends from the midbrain to the nucleus accumbens,

從中腦延伸到伏隔核——

a region important for motivation.

係個對意志好重要嘅區域

跟所有成癮嘅毒品噉

Like all addictive drugs,

it prompts a squirt of dopamine in the nucleus accumbens

佢會促使伏隔核噴出多巴胺

which gives users a surge of pleasure.

畀飲家帶來咗一股愉快嘅感覺

酒精仲會導致有啲神經元 合成同釋放內啡肽

Alcohol also causes some neurons to synthesize and release endorphins.

Endorphins help us to calm down in response to stress or danger.

內啡肽使我哋冷靜落嚟 應對壓力或者危險

Elevated levels of endorphins contribute to the euphoria

飲酒會提升內啡肽水平

and relaxation associated with alcohol consumption.

幫助放鬆自己得到欣快感

Finally,

as the liver’s breakdown of alcohol outpaces the brain’s absorption,

最後

由於肝臟分解酒精超過咗大腦吸收速度

drunkenness fades away.

醉意慢慢消失

人飲酒後嘅情況會因人而異

Individual differences at any point in this journey

can cause people to act more or less drunk.

會有不同程度嘅醉酒

For example, a man and a woman who weigh the same and drink the same amount

比如，一男一女 體重、飲酒量相同

during an identical meal will still have different blood alcohol concentrations,

進餐份量一樣 仍然喺血液度

會有唔同嘅酒精濃度（BACs）

or BACs.

This is because women tend to have less blood—

女性因為往往有較少嘅血液——

women generally have a higher percentage of fat,

而身體脂肪通常比例較高

which requires less blood than muscle.

脂肪比肌肉需要少啲血液

A smaller blood volume, carrying the same amount of alcohol,

若較小血量，負載相等嘅酒精

means the concentration will be higher for women.

意味著女性血液度酒精濃度較高

Genetic differences in the liver’s alcohol processing enzymes also influence BAC.

有基因差異嘅肝臟酒精加工酶 也會影響酒精濃度

And regular drinking can increase production of these enzymes,

經常飲酒會增加呢啲加工酶

contributing to tolerance.

提升身體對酒精嘅承受能力

On the other hand, those who drink excessively for a long time

另一方面，長期飲過量酒嘅人

may develop liver damage, which has the opposite effect.

可能會損害個肝 因而產生相反嘅效果

Meanwhile, genetic differences in dopamine, GABA,

由於遺傳嘅差異，可能增加多巴胺

and endorphin transmission may contribute to risk

γ-氨基丁酸同內啡肽嘅傳送

for developing an alcohol use disorder.

導致酗酒嘅風險

Those with naturally low endorphin or dopamine levels may self-medicate

天生安多酚或多巴胺水平低嘅人通過飲酒

through drinking.

可作自我治療

Some people have a higher risk for excessive drinking

有啲人好易飲過龍

due to a sensitive endorphin response that increases the pleasurable effects

由於內啡肽敏感嘅反應

增加咗酒精帶來愉快嘅感覺

of alcohol.

有啲人 γ-氨基丁酸嘅傳輸有差異

Others have a variation in GABA transmission

that makes them especially sensitive to the sedative effects of alcohol,

使佢哋對酒精嘅鎮靜作用特別敏感

which decreases their risk of developing disordered drinking.

降低咗佢哋發展成酗酒嘅風險

Meanwhile, the brain adapts to chronic alcohol consumption by reducing GABA,

大腦適應長期飲酒嘅做法 係透過減少傳送 γ-氨基丁酸

dopamine, and endorphin transmission, and enhancing glutamate activity.

多巴胺同內啡肽 並增強谷氨酸嘅活性

This means regular drinkers tend to be anxious, have trouble sleeping,

意味著經常飲酒嘅人 往往會焦慮同瞓唔著

and experience less pleasure.

同時體驗到更少快樂

These structural and functional changes can lead to disordered use

呢啲結構同功能變化 會導致冇節制噉飲酒

when drinking feels normal, but not drinking is uncomfortable,

當人飲酒就感覺到正常 唔飲就唔舒服嗰時

establishing a vicious cycle.

會形成惡性循環

So both genetics and previous experience impact how a person experiences alcohol—

就住遺傳同過往嘅經歷 都會影響人點樣體驗酒精——

which means that some people are more prone

呢個意味著有啲人更容易

to certain patterns of drinking than others,

比其他人鍾意某啲飲酒方式

and a history of consumption leads to neural and behavioral changes.

同時消費歷史會導致神經同行為變化