Why you should avoid vegetable oil – a mitochondria perspective 從線粒體的層面探討為什麼植物油是很不健康的食物

This article is a digest from chapter 5 in Catherine Shanahan’s 2020 new book The Fatburn FiX. The title of the chapter is “Mitochondria: Your Cells’ Energy Generators“. This is my 3rd article to help you understand why you should avoid vegetable oil in your diet. The previous two articles are Why Is Vegetable Oil among the Most Unhealthy Food to Avoid and Linoleic acid.

(A bi-lingual version of this post will be available by end of 9/29.)

本文摘自凱瑟琳·沙納漢(Catherine Shanahan)2020年新書《 The Fatburn FiX》第5章。 本章的標題是“線粒體:細胞的能量產生器”。 這是我針對為什麼飲食中應避免食用植物油這個議題的第三篇分享文章。 前兩篇文章是 為什麼植物油 (沙拉油)是最不健康的食物之ㄧ?笨蛋,問題是在亞油酸 。

I read Dr. Cate Shanahan’s Deep Nutrition back in early 2017 shortly after it’s published. The key messages in Deep Nutrition are:

  1. Sugar is bad to your health.
  2. Worse than sugar is vegetable oil (to be precise, it should be “seed oil”, or more specifically, Polyunsaturated Fatty Acid, PUFA, or even more precisely it’s the high ratio of linoleic acid in it.)
  3. When the two are combined in your food, it creates a perfect storm to ruin your health.

凱特·沙納漢(Cate Shanahan)博士的第一本暢銷書深層營養(Deep Nutrition)我在它2017年初出版後不久就讀了。 深層營養中的主要訊息是:

  • (或高澱粉) 對健康有害。
  • 比糖更糟的是植物油(準確地說,應該叫“菜籽油”((就是台灣人炒菜用的所謂沙拉油)),或更確切地說,是多不飽和脂肪酸,PUFA,或者更精確地說,是PUFA中的亞油酸 linoleic acid)。
  • 植物油一起吃,會產生完美風暴,傷身程度 1+1 遠大於 2!

In her 2020/03 new book The Fatburn Fix: Boost Energy, End Hunger, and Lose Weight by Using Body Fat for Fuel, Dr. Shanahan’s key message is (in my words) “Turn your body into a fat-burning machine is the ultimate strategy to fix and stay away from chronic diseases”.

在她的2020/03年新書燃脂療法:通過使用體內脂肪作為燃料來提高能量,消除飢餓和減輕體重裡,Shanahan博士的主要信息是(用我的話說)“把您的身體調整成像是一部可以高效率燃燒脂肪的機器是遠離慢性疾病的最佳策略”。

How do you do that? By eating the right food. Based on the 3 key messages in Deep Nutrition, it’s not surprising that eating the right food means eating more healthy fat. But what is healthy fat? In The Fatburn Fix, Dr. Shanahan takes us through the nuances of the what and why of “healthy fat”, starting in this chapter, deep down from the mitochondria in our cells.

問題是要怎麼調整呢? 答案是:吃對食物。 根據“深層營養”書中的3條關鍵信息,”吃對食物“就是要多吃健康的脂肪,也就不足為奇了。 但,什麼是”健康脂肪“?要怎麼吃才能吃到健康的脂肪? 這是一個不容易解釋清楚的問題;在這一章裡,Shanahan博士會帶著我們做深入淺出的探討,從我們細胞中的線粒體開始,

Before you start, you can read about Dr. Shanahan’s credential here, which includes the PRO Nutrition program she created for the NBA team LA Lakers in 2013, when she helped the team change their diet to low-carb (and somewhat ketogenic) hence improved the players’ game performance. (Here is a 2013 interview with Dr. Shanohan by NBA.com.)

在您開始往下閱讀之前,您可以點此連結了解Shanahan博士的專業經歷背景,包括她在2013年擔任NBA洛杉磯湖人隊營養顧問時創建的PRO Nutrition計劃,當時她幫助球員們將飲食改為低碳水化合物(接近生酮),湖人隊也因此在賽季裡表現更優異。 (可以讀這篇NBA.com在2013年對Shanohan博士的採訪。)

“…[W]e trust Dr. Cate implicitly. I’ve seen great results from it from when I started doing it last year.” 

          – Kobe Bryant, LA Lakers

“我基本上是相信我是Shanahan博士的方案的,去年開始採行後我有看到明顯的進步。” – 科比.布萊恩,洛杉磯湖人隊

The digest starts here. 重點摘譯從這裡開始…


Key points in this chapter:

  • Every cell generates its own energy supply in mitochondria. (Remark by Coach Denys: This means every single function in human body depends on mitochondria. If our mitochondria all stop functioning, we will drop dead in less than 3 seconds.)
  • Your ability to burn fat depends on your mitochondrial health.
  • Vegetable oils prevent mitochondria from generating energy with normal efficiency.

本章重點:

  • 每個細胞所需要的能量都是靠該細胞中的線粒體產生的。 (防彈大叔補充說明:這表示人體的每個功能都必須仰賴線粒體。一個人的線粒體如果全部停止運轉,這個人不到3秒就會立即死亡。)
  • 人體新陳代謝是否可以靠燃燒脂肪來產生能量,取決於線粒體的健康狀況。
  • 植物油會降低線粒體正常產生能量的功能。
Electron Transport in the Energy Cycle of the Cell. (http://hyperphysics.phy-astr.gsu.edu/hbase/Biology/etrans.html)

Mitochondria are tiny chambers inside your cells, which textbooks usually draw to look like baby bassinets. They serve as miniature energy generators inside every cell in your body, running every minute of every day, generating just the right amount of energy to meet the needs of your cells… your mitochondria are more like independent power generators, each one providing energy for its own cell.

線粒體是細胞內的一種微小腔室,教科書通常將它們畫成看起來像一個嬰兒搖籃。 它們其實是人體每個細胞內的微型能量產生器,每ㄧ天每一分鐘都在運行,產生適量的能量來滿足細胞的需求……線粒體像是個獨立的發電機,為它所存在的那個細胞提供能量。

(Remark by Coach Denys: Except the 1st photo, the cover of the book, and the last, the graph showing fueling efficiency with different types of fat, all other photos in this article are from my research on the topic of “energy production in mitochondria” . The link to the original research article is provided with each photo.)

(防彈大叔補充說明:除了第一張照片((本書的封面))以及最後一張((顯示不同類型脂肪的燃料效率的圖表))以外,本文中的所有其他照片均來自於我對“線粒體中的能量產生”這個議題的研究,每張照片的下面也都附有研究報告的連結。)

The more active a cell is, the more energy mitochondria generate… Every calorie you’ve ever burned in your life was burned inside your mitochondria.

If your mitochondria function efficiently, your cells can get all the energy they need all the time, giving them the opportunity to function at their peak. If your mitochondria don’t function efficiently, then your cells can’t get all the energy they need and can’t always function properly.

細胞越活躍,線粒體必須產生的能量就越多。您活著時燃燒的每一卡路里能量都來自線粒體。

如果線粒體有效發揮功能,您的細胞就可以持續取得所需的所有能量,進而發揮細胞該有的最佳功能。 如果線粒體無法有效發揮功能,那麼您的細胞將無法獲得所需的全部能量,也就無法始終正常發揮功能。

What makes mitochondria less efficient than they should be? It turns out that just like mechanical engines, our biological engines are designed to burn a certain kind of fuel. If you provide mitochondria the fuel they’re designed to burn, they work at peak efficiency. If you provide mitochondria the wrong kind of fuel, they don’t. This efficiency, or lack of it, is the most important determinant of your overall health.

Mitochondria are incredibly fuel-flexible. They can generate energy from all three macronutrients: sugars, amino acids (the building blocks of proteins), or fatty acids.

This incredible fuel flexibility is made possible because other organelles inside the cell work in cooperation with mitochondria to break all kinds of molecules down into two-carbon units, called acetyl groups. These two-carbon units are the basic fundamental fuel mitochondria use to produce energy.

是什麼造成線粒體的效率低於應有的水平的? 事實證明,就像機械發動機一樣,我們的生物發動機也被造物者設計成只適合用某幾種燃料燃燒。 如果您提供對的燃料給線粒體燃燒,它們將以最高效率運行。 如果您提供的燃料錯誤,線粒體就不會以最高效率。 線粒體的運作效率是決定人體健康狀況的最重要因素。

線粒體具有極大的燃料靈活性。 它們可以用三種常量營養素中產生能量:糖,氨基酸(蛋白質的組成部分)或脂肪酸。

能有這種令人難以置信的燃料靈活性,是因為細胞內的其他細胞器與線粒體協同工作,將各種分子分解為兩個碳原子的單元,稱為乙酰基。 這雙碳單位是線粒體產生能量的基本燃料。


THE PROS AND CONS OF FUELING CELLS WITH SUGAR 靠燃燒糖(碳水化合物)當能量來源的優缺點

Pros 優點

  • A small amount of glucose is always present in your bloodstream and therefore readily available to serve as fuel. 血液中始終存在少量葡萄糖,因此可以隨時用作燃料。
  • Exercise and stress can increase the amount of sugar in the bloodstream, thanks to stress hormones cortisol and adrenaline. 運動和壓力會提升血液中的皮質醇腎上腺素,從而增加血液中的糖含量

Cons 缺點

  • All sugar is sticky, and too much in your tissues can cause problems. 所有的糖都是粘性的,太多的時候會在細胞組織中造成問題。
  • The amount of sugar present cannot be increased very much during exercise and stress, generally not enough to serve all the body’s needs, causing you to feel energy dips if you can’t burn body fat. 在運動和壓力期間,血液中的糖含量無法快速提升,通常不足以滿足人體的所有需求,如果您不能燃燒體內脂肪,就會感到能量下降。
  • Consuming sugar to raise blood sugar back up again can shut off the supply of fat from your body fat. 靠食用糖以增加血糖會中斷身體靠燃燒脂肪當能量來源的能力。
  • Glucose has six carbons, but only four can be used for energy generation. The other two are released as carbon dioxide gas. 葡萄糖有六個碳原子,但只有四個可用來燒釋放能量,另外兩個碳原子會以二氧化碳氣體的形式釋放。
  • Carbon dioxide in high amounts can acidify your mitochondria. 大量的二氧化碳會讓您的線粒體酸化。
  • Acid in the mitochondria reduces something called the proton gradient, which means the mitochondria can’t generate ATP energy as efficiently.線粒體的酸化會降低質子梯度,這意味著線粒體無法有效地產生ATP能量。 (Remark by Coach Denys: You can read more about how mitochondria generate ATP through proton gradient in this book, where the mechanisms in the two diagrams below are discussed. 防彈大叔補充說明:您可以在這本書中詳細了解線粒體如何通過質子梯度產生ATP,並在下面的兩個圖中討論了該機理。)
The general mechanism of oxidative phosphorylation. (Source: Molecular Biology of the Cell. 4th edition., https://www.ncbi.nlm.nih.gov/books/NBK26894/)
The two components of the electrochemical proton gradient (Source: Molecular Biology of the Cell. 4th edition., https://www.ncbi.nlm.nih.gov/books/NBK26894/)

THE PROS AND CONS OF FUELING CELLS WITH KETONES (from fat) 靠燃燒酮體(脂肪)當能量來源的優缺點

Pros 

  • Using the same amount of oxygen, cells generate more ATP energy when burning ketones than when burning sugar. 使用相同量的氧氣,細胞燃燒酮比燃燒糖產生更多的ATP能量。
  • Brain cells given access to ketones can tolerate very low blood sugars, down to one-tenth of normal values. 在有提供酮體的情況下,腦細胞可以忍受極低的血糖,低至正常值的十分之一。
  • When ketones are available, the cell can get access to more fuel than it can when relying on sugar. 當有酮體存在時,與依靠糖時相比,細胞可以獲得更多的燃料。
  • The transporter that takes ketones from the blood to the cell interior works more efficiently than the glucose transporter. “從血液中吸收酮到細胞內部的轉運蛋白” 比 “負責把葡萄糖從血液中吸收到細胞內部的轉運蛋白” 的轉運效率更高。
  • Because ketones can be made from body fat, you have the ability to make them for an extended period.由於酮體可以由體內脂肪產生,因此您可以長時間使用酮(不必靠進食或分解肌肉細胞)。

Cons 缺點

  • The body does not store ketones and they are not available in food, so you only have access to them when your liver is making them. 人體無法儲存酮體,食物中也沒有,因此只能靠肝臟製造。
  • Your liver only makes a limited amount of ketones, and only under certain conditions that rarely occur when you’re metabolically unhealthy. 您的肝臟僅產生有限量的酮,並且僅在某些情況下才可以產生,當您的新陳代謝不健康時,肝要產生酮體更難。
  • While healthy folks make ketones from body fat, when you’re metabolically unhealthy, the body can also make ketones from protein, which requires breaking down muscle. 健康的人會通過體內脂肪來製造酮,但是當您的新陳代謝不健康時,身體只能靠通過蛋白質來製造酮,這需要分解肌肉 (當然不是一件好事)。

THE PROS AND CONS OF FUELING CELLS WITH PROTEIN 靠燃燒蛋白質當能量來源的優缺點

Everything you see when you look at yourself in the mirror is made of protein. Your skin, hair, nails, and much of the rest of your body parts are all manufactured from about twenty different amino acids that form the building blocks of proteins. Unlike fat, which we store in great quantity, and even unlike sugar, which we store in lesser quantity than fat, we have almost no place to store excess protein. So when we eat more than we need, the body has to burn it off, or convert the excess to fat or sugar for storage.

你照鏡子時看到的自己所有部位都是蛋白質。 您的皮膚,頭髮,指甲和身體其他大部分部位都是由約二十種不同的氨基酸構成的,這些氨基酸構成蛋白質的組成部分。 與我們體內可以大量存儲的脂肪不同,甚至與可存儲的數量更少的糖不同,蛋白質在人體內(除了已經變成組織的部分)幾乎無法被儲存起來當預備燃料用。 因此,當我們進食過量的蛋白質時,身體必須將其燃燒掉,或將多餘的食物轉化為脂肪或糖進行儲存。

Pros 優點

Certain cells in the small intestine may require amino acids for fuel. There’s always an abundance of amino acids available in the bloodstream, in the form of the major blood protein called albumin. Few cells actually use albumin for energy, however, in spite of this abundance. 

小腸中的某些細胞可能需要氨基酸作為燃料。 (血液中一直會存在大量氨基酸,主要以血液蛋白((白蛋白, albumin))的形式存在。 儘管血液中有如此多的蛋白質,實際上人體很少有細胞可以使用血液蛋白作為能量來源。)

Cons 缺點

As is the case with sugar and fatty acids, amino acids too must be converted to acetate to use as fuel. Converting amino acids to acetate is a much more difficult process because amino acids contain nitrogen, which is highly reactive and must be eliminated by the kidney and/or liver. A person who uses a lot of protein for fuel exposes these organs to a lot of nitrogen. A common complication of protein fueling is gout, a disease that occurs when crystals of uric acid form in the joints and cause pain and swelling. High levels of uric acid cause gout, and when the body has to eliminate a lot of nitrogen, uric acid levels can climb.

與糖和脂肪酸一樣,氨基酸也必須轉化為乙酸鹽才能用作燃料。 將氨基酸轉化為乙酸鹽的困難度(相較於糖和脂肪)高很多,因為氨基酸中含有氮,氮具有很高的反應性,必須被腎臟和/或肝臟清除。 使用大量蛋白質作為燃料的人會使這兩個器官暴露於大量氮中。 大量依靠蛋白質當燃料的常見並發症是痛風,痛風是一種尿酸結晶在關節中形成並引起疼痛和腫脹的疾病。 當人體必須排除大量的氮時,尿酸水平會上升,高含量的尿酸會導致痛風。


FAT: THE CONTROVERSIAL FUEL 脂肪:俱高度爭議性的燃料

A proper discussion of fueling with fat depends entirely on details that few medical textbooks ever go into, much less diet books for a lay audience, which is why there’s been so much confusion around whether fat is “good” or “bad.” So we need to do this pro and con section a little differently than the other three.

要針對用脂肪當燃料這個議題討論,就得進入一些連醫學教科書中都很少提到的細節,更不用說那些市面上寫給外行人看的飲食營養書籍了,這就是為什麼大部分人對“什麼是好脂肪、什麼是壞脂肪”這個問題都搞不清楚。 因此,我們針對用脂肪當燃料的優缺點分析需要更深入一點的探討。

KNOW YOUR FATS 認識你吃的脂肪

One more reason the good fat–bad fat discussion is so full of unresolved arguments is that it’s truly a discussion about chemistry. And many of the experts leading the public discussion are not as well versed in the chemistry as they should be.

到底什麼是好脂肪什麼是壞脂肪這個議題之所以會一直爭吵不休,原因之一在於這是一個與化學相關的議題,但時下在這個議題裡引領風騷的一些所謂專家其實對化學不夠內行。

When discussing the health effects of fat, we can’t simply use the term “fat.” It’s not specific enough. We need to specify the fatty acid composition of the food in question. Is it high in saturated fatty acids, for example, or is it high in polyunsaturated fatty acids? Nor should we use the general term “good” or “bad” because whether a food with a given blend of fatty acids is “good” or “bad” for you depends on how your body is using the fat. We need to specify a metabolic function. Are you using fats for fuel? For building a healthy brain? Or for sending chemical messages? Fatty acids that are well suited for sending chemical messages are not well suited for use as fuel, and vice versa. To determine which fats are best suited for fueling your mitochondria, the essential quality to evaluate is molecular stability. To be a good fuel, a fatty acid needs a good deal of stability. It especially needs to be able to resist reacting with oxygen. Oxygen is a very destructive molecule, and it can react in an uncontrolled, literally explosive fashion. If a fatty acid is unstable, then the attempts to extract energy typically yield very little usable energy, and a much larger proportion of damaging energy, as we’ll see. Fueling with unstable fatty acids can damage the mitochondria, and fueling with unstable fats on a regular basis can damage the rest of the cell.

在討論脂肪對健康的影響時,我們不能簡單地使用“脂肪”一詞,因為這樣太含糊。我們需要針對所討論的食物中所含的不同脂肪酸成分組成講清楚。例如,飽和脂肪酸含量高還是多元不飽和脂肪酸含量高?我們也不應使用“好”或“壞”這個通用術語,因為含有特定脂肪酸混合物的食物對您來說是“好”還是“壞”取決於您身體如何使用脂肪。我們也必須講清楚我們討論的是哪一種代謝功能。是使用脂肪作為燃料(能量來源)嗎?還是為了建立健康的大腦?或是為了發送化學信息?適合發送化學信息的脂肪酸其實不適合用作燃料,反之亦然。為了確定哪種脂肪最適合被用來當作線粒體的能量來源,要評估的最基本因素是分子穩定性。要成為良好的燃料,脂肪酸需要具有很高的穩定性。尤其需要能夠抵抗與氧分子的反應。氧是一種極具破壞性的分子,它可以用一種不受控制的、接近爆炸性的方式發生反應。如果脂肪酸不穩定,那麼轉換能量的嘗試通常會產生很少的可用能量,倒是破壞性能量產生的比例會更大(下面我們就會討論到)。用不穩定的脂肪酸當然廖會損壞線粒體,經常性地使用不穩定的脂肪當燃料也會損壞細胞的其餘部分。


QUICK OVERVIEW OF MAJOR TYPES OF FAT 簡介幾種主要的脂肪酸

Saturated Fat (SFA, Saturated Fatty Acid) 飽和脂肪酸

Coconut, lard, and butter are all examples of good saturated fat sources. The term “saturated” refers to the fact that there are no empty spaces on the molecule where another molecule could potentially react. Saturated fatty acid molecules are kind of like long dining tables with a friendly person seated at every chair. With hydrogen molecules (friendly people) sitting at every one of the chairs, there is no empty seat, and that helps to prevent unwanted guests, like oxygen, from sliding in and disrupting the happy saturated fatty acid dinner party conversation. Being saturated with hydrogen atoms makes saturated fat chemically stable and capable of resisting oxygen attacks. Saturated fat is not only chemically stable; it’s also physically stiff. The physical stability makes it very useful as a building block for our body’s cell membranes. Saturated fat is stable thanks to the fact that it’s chock-full of little hydrogen atoms, or “saturated” with them. These hydrogen atoms are packed between the bigger carbon molecules and stabilize the long chain of carbon atoms that might otherwise bend and sway a little bit. Think of hydrogen atoms adding stability the way mortar stabilizes a stack of bricks.

椰子油,豬油和奶油都是很好的飽和脂肪來源。所謂“飽和的”是指:分子結構上沒有空的位置可以讓另一個分子安插進來。飽和脂肪酸分子就像是一條長餐桌,每個椅子上坐著一個友好的人。每個椅子上都坐著氫分子(友好的人),沒有空座位,這有助於防止有害的客人(例如氧氣)滑入並打亂快樂的飽和脂肪酸晚餐聚會的談話。因為所有氫原子都滿席坐好(飽和),這樣的結構讓飽和脂肪酸在化學上非常穩定並能夠抵抗氧分子的侵蝕。飽和脂肪不僅在化學上穩定,而且還具有物理穩定性。它在身體細胞裡結構很僵硬。物理穩定性使其非常有用,可作為人體細胞膜的基石。飽和脂肪之所以穩定,是因為它充滿了微小的氫原子,或者被氫原子們“飽和”了。這些氫原子堆積在較大的碳分子之間,並穩定了碳原子的長鏈,否則這些碳原子可能會彎曲並稍微搖擺。氫原子會增加穩定性,就像水泥工在堆砌一面牆時用水泥來固定磚頭一樣。

Monounsaturated Fat (MUFA, Monounsaturated Fatty Acid) 單元不飽和脂肪酸

Olive oil, peanut oil, and the oil from today’s most revered nut, Sir Almond, are all examples of good monounsaturated fatty acid sources. Monounsaturated fat gets its name from the fact that there is one (“mono”) empty space on the molecule where another molecule could potentially react. Instead of being saturated, it’s missing one set of hydrogen atoms. Missing one set of hydrogen atoms means there is one empty seat at that long fatty acid dinner party. You might wonder if oxygen could squeeze into that seat and cause a disturbance. But fear not. It turns out that oxygen is such a big louse that he actually needs two seats, and he won’t bother crashing a party with just one open spot.

橄欖油,花生油和當今最受推崇的堅果杏仁油都是很好的單元不飽和脂肪酸來源。 單元不飽和脂肪之所以得名,是因為分子上有一個(“單”)空的空間,可以讓另一分子發生反應(插進來)。 它沒有飽和,而是缺少一組氫原子。 缺少一組氫原子意味著在那個漫長的脂肪酸晚宴上只有一個空位。 您可能想知道氧氣是否會擠入該座位並造成乾擾。 但是不要擔心。 事實證明,氧分子其實是個胖子(體積巨大),以至於他實際上需要兩個座位,他不會為了單一個空位而搞亂一次聚會。

The relatively high monounsaturated fat content of olive, peanut, and almond oil gives these oils a special ability to generate energy quickly, as you’ll see below.

橄欖油、花生和杏仁油裡面因為富含這種單元不飽和脂肪酸,具備了可以快速產生能量的特性,下面會談到…

Polyunsaturated Fat (PUFA, Polyunsaturated Fatty Acid) 多元不飽和脂肪酸

The good fat–bad fat discussion is made especially confusing—even to doctors—when we start talking about polyunsaturated fat (PUFA) because while we need some in our diet, it can make us sick if we have too much. Polyunsaturated fatty acids are known as “essential” fatty acids because it is essential that we eat some. But the amount our bodies require is a small amount, something like 3 to 5 grams per day of each (the exact amount we need has not been well established). Today, 80 percent of the average American’s fat calories come from vegetable oils, meaning we’re getting on average of 50 grams of PUFA per day, or about five times what our bodies can handle.

當我們開始談論多元不飽和脂肪酸PUFA)時,關於好脂肪-壞脂肪的討論就會變得很混淆不清(即使對很多醫師也一樣),因為儘管我們在飲食中是需要一些PUFA,但如果我們攝入過多PUFA,很多健康問題就會開始產生。 多元不飽和脂肪酸被稱為“必需的”脂肪酸,因為(人體內部無法自行製造)我們必須靠進食取得。 但是我們的身體需要的量很小,大約每天3至5克(我們需要的確切量在科學界尚未完全確定)。 但今天的現況是,美國人平均脂肪熱量中的80%來自植物油(植物油含大量的PUFA),這意味著一般民眾平均每天要攝取50克PUFA,大約是人體能承受的上限的五倍。

The much bigger problem with excessive PUFA consumption is its instability. Because PUFAs are extremely unstable molecules, when PUFA concentrations rise above what our cells are designed to handle, they can wreak atomic havoc inside the cell. The trouble starts when oxygen reacts with polyunsaturated fatty acids. Oxygen can actually crack the molecule open at one of its double bonds, exposing bond energy that causes a major problem. The cracked-open polyunsaturated fat forms a dangerous kind of molecule called a free radical. … When free radicals form inside your cells, it’s a little like having a fire spark inside your home. It can quickly get out of control, consuming your furniture, your walls, climbing to the second floor. In the same way, when your cells are flooded with too much PUFA, oxygen reactions may start damaging your cell membranes and disrupting normal activity inside your cells at any moment. Back when our consumption of these oils was a fraction of what it is now, the body could quickly control any oxygen-induced fires using antioxidants. Now that we are eating so much unstable fat, we are putting our body tissues at risk for out-of-control oxidation reactions. These reactions essentially burn our cell membranes at the submicroscopic level. (This leads to early onset of numerous diseases and aging.)

過量攝取多元不飽和脂肪酸(PUFA)的更大問題是它的不穩定性。由於PUFA是極其不穩定的分子,因此當PUFA濃度升高到我們的細胞所能承受的水平以上時,它們會在細胞內原子層面造成破壞。當氧氣與多元不飽和脂肪酸起反應時,麻煩就開始了。氧氣實際上可以使該分子在其雙鍵之一處打開,從而暴露出引起主要問題的鍵能(bind energy)。裂開的多元不飽和脂肪就變成一種危險的分子,稱為自由基。 …當細胞內形成自由基時,就好像你家屋內冒出火花。它很快就會失控,消耗掉家具,牆壁和二樓。同樣,當您的細胞被過多的PUFA淹沒時,氧化反應可能隨時開始損害細胞膜並破壞細胞內部的正常活動。幾十年前阿公阿嬤的年代,我們對這些油的消費只是現在的一小部分,在那種狀態下人體可以使用抗氧化劑迅速控制任何由氧氣引起的火災。但現在,人們一天到晚在吃大量不穩定的脂肪(防彈大叔補充說明:植物油在現代人的飲食裡無所不在),使我們身體的組織面臨無法控制的氧化反應的風險。這些反應基本上會在我們在細胞深層傷害我們的細胞膜。(進而導致許多疾病的早期發作和衰老。)


THE BEST AND WORST FATTY ACIDS FOR FUELING YOUR CELLS 人體細胞能量來源:最好和最差的脂肪酸

In 2002, a group of Italian scientists published results of an experiment testing the ability of four different fatty acids to support mitochondrial function. They measured mitochondrial function using a special fluorescent probe that would glow a garish greenish yellow when mitochondria were functioning properly. In a sense, they literally evaluated how well each of the four fatty acids could “keep the lights on” inside our cells.

2002年,一群意大利科學家發表了一項實驗結果,測試四種不同脂肪酸被拿來當作燃料時支持線粒體功能的能力。 他們使用特殊的熒光探針測量線粒體功能,當線粒體功能正常時,該探針會發出帶點綠色的黃色光芒。 從某種意義上說,他們就是評估了四種脂肪酸中的每一種可以多有效率地維持細胞內部的活力。

The crucially important discovery is that polyunsaturated fatty acids (PUFA) trigger a massive decline in energy production, making them useless as a cellular fuel. The study authors explain that the energy production dropped because the unstable fatty acids cause a special protein, called the permeability transition pore, to open, thus protecting the mitochondria from destroying itself. Think of a circuit breaker shutting off power to prevent your hair dryer from melting your wiring. This slowdown in energy production occurs whenever a cellular fuel burns too hot, and in doing so generates excessive oxidative stress. When energy production slows, fuel delivery slows, preventing further deliveries of the offending and dangerous polyunsaturated fuel.

最重要的發現是,多元不飽和脂肪酸(PUFA)引發了能源生產的大幅下降,使它們無法被用作細胞燃料。 該研究的作者解釋說,不穩定的脂肪酸導致細胞為了保護線粒體不被自身能量燒壞,把一種稱為通透性轉換孔的特殊蛋白質打開了。這種機制和現象類似我們家裡一般有一個斷路器,必要時會切斷電源,以防止吹風機熔化電源線。 每當細胞燃料燃燒得太熱,產生過度的氧化應激時,細胞的能量生產就會以這種方式降低。 能量生產ㄧ放慢,燃料輸送就會減慢,從而阻止進一步輸送有害和危險的多元不飽和脂肪酸燃料。(類似一種保護機制)

Result of the 2002 experiment showing different abilities of four different fatty acids in supporting mitochondrial function. (Page 103, “The Fatburn Fix”.)

Remarks and takeaway by Coach Denys: 防彈大叔補充說明:

  • The result of inefficient energy production includes the generation of way more free radicals and heat, which lead to inflammation in the cells of your body – the source of almost all health problems, starting with insulin resistance and obesity.
  • 低效率的能量產生過程會導致的後果包括產生太多自由基和熱,進而導致體內細胞的發炎(inflammation) – 那正是所有慢性病的源頭,病情從胰島素抗租和發胖開始。
  • All food contains PUFA, MUFA, and SFA, just in different ratio. The PUFA ratio in vegetable oil is the highest among all types of food.
  • 所有的食物都內含 PUFA, MUFA, 和 SFA,只是比例不同。植物油 (也就是沙拉油/炒菜油/菜籽油) 內含的 PUFA (多元不飽和脂肪酸) 比率遠遠高過所有其他食物!
  • The high ratio of PUFA in vegetable oil comes from its material – plant seeds, such as canola flower seeds, sunflower seeds, soy beans, and corn (that’s why the proper name of vegetable oil should be “seed oil”). Other food with high ratio of PUFA include the fat in animals fed with plant seeds (soy beans and corn). Yup, that’s the majority of the poultry and pork on the market today world-wide. How to further reduce PUFA in your diet after cutting vegetable oil is a topic for another article. Stay tuned.
  • 食物裡富含的大量PUFA來自其原料,也就是一些植物和蔬菜的種子,例如油菜籽、葵花籽、大豆和玉米(這也是我為什麼一直在說所謂的植物油更正確的名稱應該是菜籽油)。
  • Oil such as avocado oil, coconut oil and olive oil are not considered “vegetable/seed oil” because they are made from the fruits of plants, not the seeds.
  • 酪梨油、椰子油、和橄欖油不算植物油(菜籽油),因為它們是從植物的果實提煉出來的,而不是從種子提煉出來的。
  • If I got only 5 seconds to share one single health advice with my loved ones, it’d be “remove vegetable oil in your diet completely“.
  • 如果我只有5秒鐘的時間可以分享一句健康相關的簡短忠告給我所關愛的人,那句話就是:“不要吃任何植物油”。
  • Avoid PUFA-rich food like a plague.
  • 看到 多元不飽和脂肪酸的食物 規避唯恐不及就對了!

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