How do carbohydrates impact your health? - Richard J. Wood

6,531,855 views ・ 2016-01-11

TED-Ed


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翻译人员: Tianchang Luo 校对人员: Yolanda Zhang
00:06
Which of these has the least carbohydrates?
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这些(食物)中哪些 含碳水化合物最少呢?
00:09
This roll of bread?
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这卷面包?
00:10
This bowl of rice?
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这碗米饭?
00:12
Or this can of soda?
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或者这罐苏打水?
00:14
It's a trick question.
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这是一个很难的问题。
00:15
Although they may differ in fats, vitamins, and other nutritional content,
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尽管它们的脂肪、维生素和 其他营养物质的含量不同,
00:19
when it comes to carbs, they're pretty much the same.
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但碳水化合物的含量几乎是相同的。
那么这对于你的饮食意味着什么呢?
00:23
So what exactly does that mean for your diet?
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00:26
First of all, carbohydrate is the nutritional category for sugars
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首先,碳水化合物是一类 可以通过你的身体
00:30
and molecules that your body breaks down to make sugars.
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被分解生成糖类的物质。
00:34
Carbohydrates can be simple or complex depending on their structure.
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根据其结构不同,碳水化合物可以很简单, 也可以很复杂。
00:38
This is a simple sugar, or monosaccharide.
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这是一种结构简单的糖,或者叫单糖。
00:42
Glucose, fructose, and galactose are all simple sugars.
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葡萄糖,果糖,半乳糖都是结构简单的糖,
00:46
Link two of them together, and you've got a disaccharide,
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把这些糖中的其中两种连接起来, 你就得到了二糖,
00:50
lactose, maltose, or sucrose.
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乳糖,麦芽糖或者蔗糖。
00:55
Complex carbohydrates, on the other hand,
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另一方面,复合碳水化合物
00:57
have three or more simple sugars strung together.
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是由两种或者三种单糖形成的。
01:00
Complex carbohydrates with three to ten linked sugars
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由3到10个糖分子连接起来的 复合碳水化合物,
01:04
are oligosaccharides.
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称为低聚糖。
01:06
Those with more than ten are polysaccharides.
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由多于10个糖分子组成的 那些称为多聚糖。
01:09
During digestion,
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在消化的过程中
01:10
your body breaks down those complex carbohydrates
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你的身体把那些复合碳水化合物
01:14
into their monosaccharide building blocks,
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分解成它们的单糖单元,
01:16
which your cells can use for energy.
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你的细胞可以利用 这些单糖来获得能量。
01:19
So when you eat any carbohydrate-rich food,
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因此当你吃任何 富含碳水化合物的食物时,
01:22
the sugar level in your blood, normally about a teaspoon, goes up.
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你的血糖含量——正常情况下大概一茶匙 ——就会上升。
01:27
But your digestive tract doesn't respond to all carbohydrates the same.
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但是你的消化道并不是对 所有的碳水化合物都有一样的反应。
01:31
Consider starch and fiber,
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拿淀粉和纤维来说,
01:33
both polysaccharides,
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它们都是多糖,
01:35
both derived from plants,
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都是从植物中获得的,
01:36
both composed of hundreds to thousands of monosaccharides joined together,
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也都由成百上千个单糖连接而成,
01:42
but they're joined together differently,
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但是它们的连接方式不同,
01:44
and that changes the effect they have on your body.
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这就改变了它们对你身体的影响。
01:47
In starches, which plants mostly store for energy in roots and seeds,
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淀粉,是植物通常在根或者种子中 存储能量的形式,
01:51
glucose molecules are joined together by alpha linkages,
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葡萄糖分子是α键连接在一起的,
01:55
most of which can be easily cleaved by enzymes in your digestive tract.
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大部分这种键可以很容易 被你消化道中的酶断开,
02:00
But in fiber, the bonds between monosaccharide molecules are beta bonds,
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但是在纤维中,单糖分子之间的键是β键,
02:05
which your body can't break down.
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你的身体不能分解它。
02:07
Fiber can also trap some starches, preventing them from being cleaved,
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纤维也可以捕捉到一些淀粉, 避免其被分解,
02:12
resulting in something called resistant starch.
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生成一些被称为抗性淀粉的东西。
02:15
So foods high in starch, like crackers and white bread,
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因此淀粉含量高的食物, 比如薄脆饼干和白面包,
02:19
are digested easily,
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就很容易消化,
02:21
quickly releasing a whole bunch of glucose into your blood,
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快速地释放大量葡萄糖到你的血液里,
02:24
exactly what would happen if you drank something high in glucose, like soda.
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就好比你喝了一些葡萄糖含量高的饮料, 比如苏打水。
02:28
These foods have a high glycemic index,
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这些食物都有很高的血糖指数,
02:31
the amount that a particular food raises the sugar level in your blood.
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也就是某一种食物升高血糖含量的数值。
02:36
Soda and white bread have a similar glycemic index
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苏打水和白面包有相似的血糖指数,
02:39
because they have a similar effect on your blood sugar.
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因为它们对你的血糖含量有相似的影响。
02:42
But when you eat foods high in fiber, like vegetables, fruits, and whole grains,
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但是当你吃富含纤维的食物比如蔬菜、 水果,还有全麦时,
02:47
those indigestible beta bonds slow the release of glucose into the blood.
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那些难消化的β键会减慢 葡萄糖释放到血液中的过程。
02:52
Those foods have a lower glycemic index,
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那些食物的血糖指数就低一些,
02:54
and foods like eggs, cheese, and meats have the lowest glycemic index.
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像鸡蛋、奶酪还有肉这些食物的 血糖指数就是最低的。
03:00
When sugar moves from the digestive tract to the blood stream,
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当糖从消化道进入到血管中时,
03:04
your body kicks into action to transfer it into your tissues
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你的身体就会开始将糖转运到 身体组织中,
03:08
where it can be processed and used for energy.
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在这里糖会被处理生成能量。
03:10
Insulin, a hormone synthesized in the pancreas,
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胰岛素,一种在胰腺中合成的荷尔蒙,
03:14
is one of the body's main tools for sugar management.
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是身体中一种主要的血糖管理工具。
03:17
When you eat and your blood sugar rises,
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当你吃东西导致血糖升高的时候,
03:20
insulin is secreted into the blood.
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胰岛素会被分泌到血液中。
03:23
It prompts your muscle and fat cells to let glucose in
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它促进你的肌肉和脂肪细胞吸收葡萄糖,
03:26
and jump starts the conversion of sugar to energy.
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并且快速开始从糖到能量的转换。
03:30
The degree to which a unit of insulin lowers the blood sugar
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单位量的胰岛素降低血糖的程度
03:33
helps us understand something called insulin sensitivity.
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能帮助我们理解所谓的胰岛素敏感性。
03:37
The more a given unit of insulin lowers blood sugar,
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给定单位量的胰岛素降低的 血糖浓度越多,
03:40
the more sensitive you are to insulin.
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就说明你对胰岛素越敏感。
03:43
If insulin sensitivity goes down, that's known as insulin resistance.
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如果胰岛素敏感度降低, 就被称为胰岛素抗性。
03:47
The pancreas still sends out insulin,
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胰腺仍然会释放胰岛素,
03:49
but cells, especially muscle cells, are less and less responsive to it,
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但是细胞,特别是肌肉细胞, 对胰岛素做出的反应越来越少,
03:54
so blood sugar fails to decrease,
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因此血糖浓度无法降低,
03:57
and blood insulin continues to rise.
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而血液中胰岛素还会持续增加。
04:00
Chronically consuming a lot of carbohydrates
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长期摄入大量碳水化合物
04:03
may lead to insulin resistance,
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可能会导致胰岛素抗性,
04:06
and many scientists believe that insulin resistance
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许多科学家们相信胰岛素抗性
04:09
leads to a serious condition called metabolic syndrome.
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会导致一种严重的病,叫做代谢综合征。
04:13
That involves a constellation of symptoms,
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代谢综合征有许多症状,
04:15
including high blood sugar,
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包括高血糖,
04:17
increased waist circumference,
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变大的腰围,
04:19
and high blood pressure.
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和高血压。
04:21
It increases the risk of developing conditions,
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它增加了患病的风险,
04:23
like cardiovascular disease
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比如心血管疾病
04:25
and type II diabetes.
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和II型糖尿病。
04:27
And its prevalence is rapidly increasing all over the world.
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代谢综合征的患病率 在全球范围内增长迅速。
04:31
As much as 32% of the population in the U.S. has metabolic syndrome.
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多达32%的美国人患有代谢综合征。
04:38
So let's get back to your diet.
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再回到你的日常饮食吧。
04:40
Whether your food tastes sweet or not, sugar is sugar,
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不管你的食物尝起来甜不甜, 糖就是糖,
04:44
and too many carbs can be a problem.
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摄入过多的碳水化合物 会引发健康问题。
04:47
So maybe you'll want to take a pass
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那么你也许不会再选择吃
04:49
on that pasta sushi roll pita burrito donut burger sandwich.
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意大利面,寿司,皮塔饼,墨西哥玉米卷, 甜甜圈,汉堡和三明治了吧。
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