it wasn't just because animals taste great,

並不只是因為動物很好吃

it was pure necessity.

而是他們必須這麼做。

Climate change made many of the plants our ancestors relied on less available and meat bridged that gap.

氣候變遷讓我們祖先吃的食物變少，而肉食填補了空缺。

From the discovery of fire at the latest, meat became a staple of the human diet.

從已知用火開始，肉類已經成為人類飲食中不可或缺的一部分。

But over the last few years eating meat has increasingly been associated with health risks like:

但最近幾年，肉食越來越與健康危害息息相關。

heart disease, certain cancers, and an early death.

像是：心臟病、某些癌症，還有早逝

So how unhealthy is meat, really?

所以，肉食實際上有多不健康？

In this video we'll only talk about meat.

（開場音樂~）

Dairy products deserve a video of their own.

這部影片我們只談 " 肉 "

Biologically, we need to eat for three reasons:

乳製品值得由另一部影片來說明

for energy, to acquire materials to fabricate our cells,

從生物的角度上，我們必須進食有3個理由

and to get special molecules that our bodies can't make themselves.

為了能量、為了獲得製造細胞的材料

The energy and most of the materials come from the three macronutrients: fats, carbohydrates and proteins.

還有獲得我們身體無法製造的分子。

Proteins are the most important resource for repairing and replenishing our cell structures.

能量還有大多的材料來自3種營養素

The special molecules are a large variety of vitamins and minerals we need to drive metabolic processes.

脂肪、碳水化合物、蛋白質

Meat provides us with most of these things.

蛋白質是最重要資源，可以用來修復、填補我們的細胞。

It contains all essential amino acids our body needs and a lot of minerals like:

特殊的分子是各種不同的維他命、礦物質，讓身體進行新陳代謝。

iron, zinc and essential vitamins, some of which are barely found in plants like Vitamin B12.

肉食提供上面提到的大部分營養素

Only one essential nutrient is missing in most of the meat we consume: vitamin C.

它提供所有身體所需的胺基酸，還有很多礦物質，如：

It appears in almost all plants and supports our immune system

鐵、鋅、基本的維他命、還有某些在植物上不常出現的營養素，如：維他命B12

as well as the development of connective tissues.

只有一種基本的營養素在大部分的肉類食品中找不到，維他命C

After a few months without it you'd get scurvy.

維他命C出現在幾乎所有植物中， 並有助於我們免疫系統的運作，

But meat has another big advantage, it's high bioavailability.

以及結締組織的發育

Some of the nutrients in meat are broken down faster and available quicker than those from plants.

在數月缺乏維他命C後，你會得到壞血病

Spinach for example, contains more iron than meat, but it's absorbed much slower

但肉仍有其它重要的優點， 它高度的生物利用度。

and the body needs more energy to digest it.

與植物來源相較， 肉中的部分營養素可以被更快速的分解與利用

Several health benefits have also been observed in communities that rely solely on meat.

例如菠菜比肉含有更多的鐵， 但吸收就慢上許多，

The Inuit for example, are able to survive in extreme climate conditions thanks to a purely meat-based diet.

也需要耗費更多的能量來消化

Since they consume the whole animal including the organs, they get every single nutrient they need

在完全仰賴肉食的族群， 也可以觀察到一些對健康有益的情況

including vitamin C.

以因紐特人為例，有能力生存於極端氣候， 要歸功於純肉食的飲食。

So meat itself is definitely not dangerous for us.

因為他們食用包含器官的整頭動物， 他們可以獲得每一種所需的營養素，

But its health effects vary, depending on how its prepared and what animal it comes from.

也包含了維他命C

When talking about meat in the Western world,

所以肉食本身對我們是不會有危險的

we generally mean muscle tissues that have a high nutrient density,

但依據烹調方式、以及來自何種動物的不同， 對我們的健康效果也會不同

but also lack some of the vitamins that make it possible to survive on meat alone.

當在西方世界談到肉類

The most healthy animals to eat are probably fish.

我們一般指的是富含營養素的肌肉組織

Fish contains polyunsaturated fatty acids like omega-3,

但依然缺乏某些維生素

which may lower the risk of cardiovascular diseases and support anti-inflammatory immune functions.

使我們無法只靠吃肉生存

As part of a balanced diet, fish can be eaten regularly without worries.

吃起來最健康的動物

Eating fish comes with its own bag of complications though,

應該是魚類吧

like overfishing and the destruction of the oceans.

魚類含有多元不飽和脂肪酸，例如ω-3脂肪酸

We'll talk about that in another video.

其可以降低罹患心血管疾病的風險，

A close second is the most popular meat, chicken.

並維持抗炎性免疫系統的功能運作

It's regarded as the meat with the fewest health risks.

作為均衡飲食的一部分，

The only negative health effect of poultry is a bit controversial:

我們可以安心的經常吃一些魚

fat.

但吃魚也會有一些不好的外部作用

It's high content of saturated fats is associated with a higher cholesterol level and cardiovascular disease.

例如過度捕撈 以及破壞海洋

But this idea has also been criticized by a large number of scientists

我們會在另一部影片談及

arguing high cholesterol levels might be inherited and not caused by nutrition.

第二受歡迎的肉是雞肉

So in general, if you want meat and are concerned about your health, go for chicken.

被認為有著最少的健康風險

Things start to get problematic with high intakes of red meats like beef, veal, pork, lamb, horse and goat.

吃雞唯一不好的副作用是有點爭議的

A recently published study recommends for example a maximum of 23 grams of red meat per day

肥胖問題

which is a very small steak per week.

牠高含量的飽和脂肪酸， 會導致膽固醇過高與心血管疾病

However, large-scale meta-analysis studies have shown that eating 100 grams of red meat every day

但這個概念也被很多科學家批評

increases the risk of diabetes by 19%, of strokes by 11% and of colorectal cancer by 17%.

他們認為膽固醇過高與基因遺傳有關， 而非營養引起

This sounds alarming. But before we panic, let's have a look at how these studies were conducted.

所以一般來說, 如果你想吃肉

Because this brings us to the second big problem when trying to answer the question of

同時也在意自己的健康的話, 吃雞吧!

whether meat is unhealthy or not.

隨著牛肉，小牛肉，豬肉，羊肉，馬和山羊等紅肉的大量攝入，事情開始出現問題。

Most studies that linked health risks to eating red meat were case-control studies.

最近發表的一項研究建議，例如每天最多攝取23克紅肉

Which means taking a group of people with a disease and classifying them by their eating habits.

相當於每週只能吃一塊非常小的牛排

The more red meat they consume, the more likely they were to contract certain diseases.

然而，大規模的分析研究表明，每天吃100克紅肉

The problem is that it's very hard to eliminate other factors.

糖尿病風險增加19％，中風增加11％， 結直腸癌風險增加17％。

People who eat less meat tend to live a healthier lifestyle in general.

這聽起來令人震驚。 但在我們恐慌之前，讓我們來看看這些研究是如何進行的。

They tend to eat more vegetables and fruit and are less likely to smoke and drink alcohol.

因為在試圖回答這問題時將我們帶到了第二個大問題：

Most studies try to eliminate these factors, but it's extremely hard to make definitive statements.

肉是否不健康。

Things get worse when we look at processed meat though.

大多數將健康風險與食用紅肉聯繫起來的研究都是病例對照研究。

Processing meat means adding certain chemicals by

這意味著根據飲食習慣對一群患有疾病的人進行分類。

curing, smoking, sorting or fermenting

他們食用的紅肉越多，越有可能被歸類於罹患某些疾病

or in other words making it delicious.

問題在於，要排除其他因素非常困難。

Bacon, ham, salami, sausages and hot dogs contain chemicals that are harmful for us

少吃肉的人往往過著更健康的生活方式

like nitrates and nitrites that can damage the DNA in our digestive system and lead to cancer.

他們往往會吃更多的蔬菜和水果，且較少吸煙和喝酒。

The w-h-o reviewed 800 studies over 20 years,

大多數研究試圖消除這些因素， 但很難得到明確的結論。

and concluded that processed wheat is strongly linked to an increased risk of colorectal cancer.

當我們看向加工肉類時情況變得更糟。

Each extra 50 grams of processed meat per day increases your risk of cancer by 18 percent.

加工肉類意味著添加某些化學品

When it comes to cancer risk, processed meat is now in the same category as plutonium,

如保存、煙燻、分級、發酵等過程

asbestos and smoking.

或換句話說，讓它變得美味。

The w-h-o highlights that it's research is only about the question of whether or not something

培根，火腿，臘腸，香腸和熱狗含有對我們有害的化學物質

causes cancer and not to what extent.

像硝酸鹽和亞硝酸鹽，可以破壞我們消化系統中的DNA，導致癌症。

But processed meat may also significantly increase the chance of suffering from

世界衛生組織審查了20多年內的800項研究，

diabetes, strokes and coronary heart diseases.

並得出結論，加工肉類與結直腸癌風險增加密切相關。

It also makes a difference what sort of life our meat lived when it was still part of a living being.

每天額外攝取50克加工肉類， 使患癌症的風險增加18％。

It's common to feed large amounts of antibiotics to livestock

在癌症風險方面，加工肉類現在與 鈽 、

in order to prevent diseases which can spread antibiotic resistance.

石棉 、 菸害 屬於同一級別，

Combined, a high consumption of both red and processed meat

世界衛生組織強調，它的研究只涉及

could increase your chance of premature death by up to 29%.

某些因素是否會導致癌症，而不是在多大程度上。

This means if your chance of dying is at 3% this year, it's now 4%.

但加工肉類也可能會顯著增加罹患

This might not sound like a lot but tiny percentages have a huge impact on societies of millions.

糖尿病、中風和心臟病的機率

They also seem harmless until they affect you.

肉類來源的生物，其存活時的生活環境也會造成差別

To blame meat alone for bad health would be wrong though.

向牲畜餵食大量抗生素是很常見的

There is no evidence that the very essence of meat has any negative effect beyond it's high fat content.

為了預防可以傳播抗生素耐藥性的疾病。

And even this point is highly contentious.

加上紅肉和加工肉類的消費量很高

Just like with many other pleasures in life, sometimes too much of a good thing is harmful.

可以使你提早死亡的機率提高29％。

Most public health agencies suggest cutting meat consumption to 500 grams a week

這意味著如果你今年死亡的機率是3％，現在已經達到了4％

while studies suggest cutting down processed meat as much as possible.

這可能聽起來不是很多， 但微小百分比對數百萬人的社會會產生巨大影響。

So if you feast on meat no more than once or twice a week, you should be good.

而且在它們影響你之前，看似很無害。

For most people this already means a drastic change in their diets though,

因為健康狀況不好而責怪肉是錯誤的。

The average American consumes around almost 1600 grams of meat a week.

沒有證據表明肉的本質具有任何負面影響， 除了它的高脂肪含量

The average German 1100 grams a week.

而甚至這一點也是非常有爭議的。

And many of us needs much much more.

就像生活中的許多其他娛樂一樣， 有時太多的好事是有害的。

If you're not really sure, make a small note whenever you eat meat for a week or two.

大多數公共衛生機構建議每週減少500克的肉類攝取

You'll be surprised how much it really is.

而且研究建議盡可能減少加工肉類的攝取

So most people watching this video would benefit from cutting down on meat.

因此，如果你每週吃不超過一或兩次肉， 你應該不太需要擔心。

Aside from health concerns,

而對於大多數人來說，這已經意味著他們的飲食發生了巨大的變化，

there's still the fact that the meat industry is one of the largest contributors to climate change

美國人平均每週消耗近1600克肉

and has reached a scale where it's impossible to deliver millions of tons of meat

德國人平均每週1100克

and still treat animals with dignity.

我們中的許多人甚至吃得更多

We've already discussed that in detail in another video.

如果你不太確定吃了多少， 一或兩星期內每次吃肉時，做個小注記吧！

All in all, in moderation, meat is not unhealthy and you don't need to become vegetarian overnight

你真的會感到驚訝。

to have a real impact on your health and the planet.

因此，觀看此視頻的大多數人， 都能從減少肉類食用中獲益。

But your lifestyle choices do matter.

除了健康問題外，

For yourself and for others.

肉類行業仍然是氣候變化最大的導致者之一

The key is being open to trying something new once in a while.

而且即使達到數百萬噸肉的規模，

Maybe you'll discover your new favourite dish.

仍然無法有尊嚴地對待動物。

Until you try you'll never know what you'll enjoy or what you're capable of.

我們已經在另一部影片中詳細討論了這個問題。

Maybe after watching hours of Kurzgesagt videos, you've decided you'd like to learn how to animate.

總而言之，在適度的情況下， 肉不是不健康的，你並不需要一夜之間改吃素

Now you might not know this, but most of our team actually has a graphic design background.

以對你的健康和地球產生真正的影響。

Learning about design principles first before we got into animation was really key to where we are today.

但你選擇的生活方式很重要。

There's a really great new Skillshare class on using Adobe Illustrator,

為了自己，和其他人。

The software we use to create artwork by graphic designer Aaron Draplin

關鍵是要偶爾嘗試新事物

and we can personally recommend it.

也許你會發現你最喜歡的餐點。

It's full of great tips to help understand and simplify a very complicated program.

在你嘗試之前， 你永遠不會知道你會喜歡什麼或者你能做什麼。

If you want to do more afterwards, we have three animation courses of our own on Skillshare too.

也許在觀看了幾個小時的Kurzgesagt視頻後， 您已經決定要學習如何製作動畫。

Skillshare offers over 25,000 classes on topics

現在您可能不知道這一點， 但我們團隊的大多數人實際上都有圖形設計的背景。

like film and video editing, writing, design and technology from an array of skilled experts.

在我們進入動畫之前， 首先了解設計原則，是我們今天所處的關鍵。

With the Premium Membership, you can access all of them for only $10 a month.

有一個非常棒的 Skillshare 課程， 有關使用Adobe Illustrator，

And as a bonus, the first 1000 Kurzgesagt viewers to use the link in the description,

我們平面設計師Aaron Draplin用來創建藝術品的軟件

will get their first two months of Skillshare for free.

我們可以親自推薦這個課程。