How carbohydrates impact health
碳水化合物如何影响你的健康？
Which of these has the least carbohydrates, this roll of bread, this bowl of rice or this can of soda? It's a trick question. Although they may differ in fats, vitamins and other nutritional content, when it comes to carbs, they're pretty much the same. So what exactly does that mean for your diet?
这卷面包、这碗米饭和这罐苏打水，谁的碳水化合物最少？这问题有些棘手。尽管它们在脂肪、维生素和其他营养成分方面可能有所不同，但当涉及到碳水化合物时，它们几乎是一样的。所以，这对你的饮食到底意味着什么？
First of all, carbohydrate is the nutritional category for sugars and molecules that your body breaks down to make sugars. Carbohydrates can be simple or complex depending on their structure. This is a simple sugar, or monosaccharide. Glucose, fructose and galactose are all simple sugars. Link two of them together and you've got a disaccharide - lactose, maltose or sucrose.
首先，碳水化合物是指糖类和一些会被你机体分解为糖类的分子。根据结构的不同，碳水化合物可以分为单糖(simple)或多糖(complex)。这是单糖(monosaccharide)。葡萄糖、果糖和半乳糖都是单糖。把它们中的两个单糖连接联系在一起，你就得到了一个二糖(disaccharide)--比如说乳糖、麦芽糖或蔗糖。
Complex carbohydrates on the other hand, have three or more simple sugars strung together. Complex carbohydrates with three to ten linked sugars are oligosaccharides. Those with more than ten are polysaccharides. During digestion, your body breaks down those complex carbohydrates into their monosaccharide building blocks, which your cells can use for energy.
另一方面，三个或更多的单糖串在一起便成为了多糖。由三到十个相连的单糖组成的多糖称为寡低聚糖。超过十个的则是多糖。在消化过程中，这些多糖被机体分解成单糖，作为细胞能量的来源。
So when you eat any carbohydrate-rich food, the sugar level in your blood, normally about a teaspoon, goes up but your digestive tract doesn't respond to all carbohydrates the same. Consider starch and fiber, both polysaccharides, both derived from plants, both composed of hundreds to thousands of monosaccharides joined together. But they're joined together differently and that changes the effects they have on your body.
因此，当你吃任何富含碳水化合物的食物时，你的血液中的糖分水平通常会上升一茶匙左右，但你的消化道对所有碳水化合物的反应却不尽相同。比如像淀粉和纤维，两者都是多糖，都来自植物，都是由数百到数千个单糖分子聚合而成。但由于它们连接的方式不同，所以对你身体的影响也不同。
In starches which plants mostly store for energy in roots and seeds, glucose molecules are joined together by alpha linkages, most of which can be easily cleaved by enzymes in your digestive tract. But in fiber, the bonds between monosaccharide molecules are beta bonds which your body can't break down. Fiber can also trap some starches, preventing them from being cleaved, resulting in something called resistant starch.
植物大多将淀粉作为作为植物的能量物质，存储在根部和种子中。，而淀粉是由葡萄糖分子由α键连接在一起的，其中的大部分可以很容易地被你消化道中的酶分解。但在纤维中，单糖分子之间由β键连接联结，而无法被机体分解。纤维还可以捕获一些淀粉，防止它们被分解，从而产生一种叫做抗性淀粉(resistant starch)的东西。
So foods high in starch like crackers and white bread are digested easily, quickly releasing a whole bunch of glucose into your blood, exactly what would happen if you drank something high in glucose like soda. These foods have a high glycemic index, the amount that a particular food raises the sugar level in your blood. Soda and white bread have a similar glycemic index, because they have a similar effect on your blood sugar. But when you eat foods high in fiber like vegetables, fruits and whole grains, those indigestible beta bonds slow the release of glucose into the blood. Those foods have a lower glycemic index. And foods like eggs, cheese, and meats have the lowest glycemic index.
因此，像饼干和白面包这样的高淀粉食物很容易被消化，从而迅速向血液中释放出大量葡萄糖。对于苏打水也是这样。这些食物的升糖指数(glycemic index)很高。它表示某一特定食物提高你血液中糖含量的程度它表示某一特定食物提高你血糖水平的程度。苏打水和白面包有类似的升糖指数，因为它们对你的血糖有类似的影响。但是那些高纤维的食物，如蔬菜、水果和全谷物，其中不易消化的β键会减缓葡萄糖释放到你血液中的速度。这些食物的升糖指数较低。而像鸡蛋、奶酪和肉类等食物的升糖指数最低。
When sugar moves from the digestive tract to the bloodstream, your body kicks into action to transfer it into your tissues where it can be processed and used for energy.
当糖从消化道进入血液时，你的身体开始行动并将其转移到你的组织中。在那里，它可以被转化成能量供机体使用。
Insulin, a hormone synthesized in the pancreas, is one of the body's main tools for sugar management. When you eat, and your blood sugar rises, insulin is secreted into the blood, it prompts your muscle and fat cells to let glucose in and jumpstarts the conversion of sugar to energy. The degree to which a unit of insulin lowers the blood sugar helps us understand something called "insulin sensitivity".
胰岛素，一种在胰腺中合成的激素，是人体管理糖的主要工具之一。当你吃东西时，血糖水平上升，胰岛素就会分泌到血液中，从而促使你的肌肉和脂肪细胞让葡萄糖进入，并启动糖向能量的转化。我们将单位量的胰岛素降低血糖的程度称为 "胰岛素敏感性"。
The more a given unit of insulin lowers blood sugar, the more sensitive you are to insulin. If insulin sensitivity goes down, that's known as insulin resistance. The pancreas still sends out insulin but cells, especially muscle cells, are less and less responsive to it, so blood sugar fails to decrease, and blood insulin continues to rise.
单位量的胰岛素能降低的血糖越多，你便对胰岛素越敏感。而胰岛素敏感性下降则被称为胰岛素抵抗(insulin resistance)。在这种情况下，胰腺仍然分泌胰岛素，但细胞，特别是肌肉细胞对胰岛素的反应越来越小，导致血糖未能降低，而血液中胰岛素水平继续上升。
Chronically consuming a lot of carbohydrates may lead to insulin resistance and many scientists believe that insulin resistance leads to a serious condition called "metabolic syndrome". That involves a constellation of symptoms including high blood sugar, increased waist circumference and high blood pressure. It increases the risk of developing conditions like cardiovascular disease and type two diabetes. And its prevalence is rapidly increasing all over the world. As much as 32% of the population in the US has metabolic syndrome.
长期(Chronically)消耗摄入大量碳水化合物可能导致胰岛素抵抗，许多科学家认为，胰岛素抵抗会导致一种叫做 "代谢综合征 "的严重疾病。其涉及一系列的症状，包括高血糖、腰围增加和高血压。此外它还会增加患心血管疾病和二型糖尿病等疾病的概率(risk)风险。在世界各地, 代谢综合征病例正迅速增加。在美国，约有32%的人患有代谢综合征。
So let's get back to your diet. Whether your food tastes sweet or not, sugar is sugar. And too many carbs can be a problem. So maybe you'll want to take a pass on that pasta sushi roll Pita burrito donut burger sandwich.
所以回到饮食问题上：无论甘甜与否，糖就是糖。而摄入过多的碳水化合物可不是小事。了解了这些，下次在面对意大利面、寿司卷、皮塔卷饼、甜甜圈、汉堡和三明治时，你可能会说：“还是算了吧。”
2026 biochemistry chapter 7 carbohydrates.pdf
