Picture warm, gooey cookies, crunchy candies, velvety cakes, waffle cones piled high with ice cream. Is your mouth watering? Are you craving dessert? Why? What happens in the brain that makes sugary foods so hard to resist?
想像一個溫熱、黏膩的餅乾 爽脆的糖果 細緻可口的蛋糕 甜筒上堆起的冰淇淋球 讓你口水直流了嗎? 讓你想吃點心了嗎? 為什麼? 是什麼讓你的腦子
Sugar is a general term used to describe a class of molecules
無法抗拒含糖食物呢?
called carbohydrates, and it's found in a wide variety of food and drink. Just check the labels on sweet products you buy. Glucose, fructose, sucrose, maltose, lactose, dextrose, and starch are all forms of sugar. So are high-fructose corn syrup, fruit juice, raw sugar, and honey. And sugar isn't just in candies and desserts, it's also added to tomato sauce, yogurt, dried fruit, flavored waters, or granola bars.
糖是對 碳水化合物分子的 總稱 而它們存在許多食物、飲料中 只要看看你買甜食上的標簽 葡萄糖 果糖 蔗糖 麥芽糖 乳糖 右旋糖 和澱粉 都是不同形態的糖類 果糖含量高的糖漿 果汁 粗糖 和蜂蜜 而且糖類不只在糖果、點心中 它也被加到番茄醬 優格 果乾 調味水
Since sugar is everywhere, it's important to understand
和燕麥棒中
how it affects the brain. What happens when sugar hits your tongue? And does eating a little bit of sugar make you crave more?
既然糖類無所不在 我們更要了解 糖對大腦的影響 當糖沾上舌頭時 會造成什麼反應呢? 吃一點點糖 會不會讓你想吃更多?
You take a bite of cereal. The sugars it contains activate the sweet-taste receptors, part of the taste buds on the tongue. These receptors send a signal up to the brain stem, and from there, it forks off into many areas of the forebrain, one of which is the cerebral cortex. Different sections of the cerebral cortex process different tastes: bitter, salty, umami, and, in our case, sweet. From here, the signal activates the brain's reward system. This reward system is a series of electrical and chemical pathways across several different regions of the brain. It's a complicated network, but it helps answer a single, subconscious question: should I do that again? That warm, fuzzy feeling you get when you taste Grandma's chocolate cake? That's your reward system saying, "Mmm, yes!" And it's not just activated by food. Socializing, sexual behavior, and drugs are just a few examples of things and experiences that also activate the reward system. But overactivating this reward system kickstarts a series of unfortunate events: loss of control, craving, and increased tolerance to sugar.
你吃一點麥片 其中所含的糖 刺激了舌頭味蕾上的 甜味受器 受器向大腦傳送訊號 在那訊號分支傳送到 前腦中的不同區域 其中一個就是大腦皮層 大腦皮層中的不同分區 處理不同味覺訊號 苦味 鹹味 鮮味 和我們討論的甜味 訊號在這裡活化 大腦的報償系統 這個報償系統是一系列 電子與化學的傳遞鏈 橫跨大腦不同區域 它是一個複雜的網絡 但是它可以回答一個簡單 潛意識裡的問題 我要重複這個動作嗎? 在品嘗奶奶巧克力蛋糕食 你這種溫暖、放鬆的感覺 這就是你的報償系統說: 「我還要!」 而且它不只可由食物啟動 社交 性行為 和藥物 只是其中幾件 事情或經驗 可以啟動報償系統的例子 但是過度活化報償系統 會造成許多不良後果: 失控 渴望 和對糖類耐受性增加
Let's get back to our bite of cereal. It travels down into your stomach and eventually into your gut. And guess what? There are sugar receptors here, too. They are not taste buds, but they do send signals telling your brain that you're full or that your body should produce more insulin to deal with the extra sugar you're eating.
讓我們回到剛所講的麥片 它向下進入到你的胃 再到達你的腸子 誰料的到呢? 腸子也有糖類受器 它們不是味蕾 但也能傳送訊號 告訴你的腦說 你已經吃飽了 或告訴身體需要製造更多胰島素 去處理你多吃的糖
The major currency of our reward system is dopamine, an important chemical or neurotransmitter. There are many dopamine receptors in the forebrain, but they're not evenly distributed. Certain areas contain dense clusters of receptors, and these dopamine hot spots are a part of our reward system. Drugs like alcohol, nicotine, or heroin send dopamine into overdrive, leading some people to constantly seek that high, in other words, to be addicted. Sugar also causes dopamine to be released, though not as violently as drugs. And sugar is rare among dopamine-inducing foods. Broccoli, for example, has no effect, which probably explains why it's so hard to get kids to eat their veggies.
報償系統中的 主要貨幣是多巴胺 它是重要的神經傳導物質 前腦中有很多多巴胺受體 但是分佈並不平均 特定地方有密集、叢聚的受體 這些是多巴胺的熱點 也是報償系統的一部份 藥物像是酒精 尼古丁 或海洛因 會造成多巴胺受體超載 造成一些人持續追求這種快感 也就是成癮 糖經由一種較藥物和緩的機制 促成多巴胺的釋放 有些食物含糖量較低 例如:花球甘藍就沒有作用 這或許可以解釋 為什麼很難叫小孩吃青菜
Speaking of healthy foods, let's say you're hungry and decide to eat a balanced meal. You do, and dopamine levels spike in the reward system hot spots. But if you eat that same dish many days in a row, dopamine levels will spike less and less, eventually leveling out. That's because when it comes to food, the brain evolved to pay special attention to new or different tastes. Why? Two reasons: first, to detect food that's gone bad. And second, because the more variety we have in our diet, the more likely we are to get all the nutrients we need. To keep that variety up, we need to be able to recognize a new food, and more importantly, we need to want to keep eating new foods. And that's why the dopamine levels off when a food becomes boring.
說到健康食物 假設你餓了 而且決定要吃一餐 你這麼做後 多巴胺量激增 刺激報償系統的熱點 但如果你一再吃同一道菜 多巴胺量會越來越低 最後和平常無異 因為當刺激來自食物時 大腦演化出特別的機制 關注新、或不同的味道 為什麼呢? 有兩個原因 一、確定食物是否過期 二、因為如果我們的 飲食越多樣化 我們就更有可能 得到所有所需營養 為了保持多樣性 我們需要辨別新食物的能力 更重要的是 我們必須想吃新食物 這就是為什麼食物相同時
Now, back to that meal. What happens if in place of the healthy, balanced dish, you eat sugar-rich food instead? If you rarely eat sugar or don't eat much at a time, the effect is similar to that of the balanced meal. But if you eat too much, the dopamine response does not level out. In other words, eating lots of sugar will continue to feel rewarding. In this way, sugar behaves a little bit like a drug. It's one reason people seem to be hooked on sugary foods.
多巴胺變化就不明顯 回到我們所說的那一餐 如果將健康、平衡的飲食 以高糖份的食物代替 會發生什麼事呢? 如果你很少吃糖 或一次吃的不多 它的影響與均衡飲食相同 如果你吃過量 多巴胺改變並不會逐漸下降 換句話說,吃大量的糖 會繼續使人 有被回饋的感覺 這麼說來,糖就像毒品一樣 這是為什麼有人會對
So, think back to all those different kinds of sugar.
高糖食物成癮的原因
Each one is unique, but every time any sugar is consumed, it kickstarts a domino effect in the brain that sparks a rewarding feeling. Too much, too often, and things can go into overdrive. So, yes, overconsumption of sugar can have addictive effects on the brain, but a wedge of cake once in a while won't hurt you.
想想各種不同的糖 每種都各有不同 但是吃進不同的糖 都會刺激腦中的多巴胺釋放 造成被回饋的感覺 吃太多或太頻繁 都會造成超載 所以過量攝取糖類 也會造成大腦的成癮