1 00:00:00,520 --> 00:00:03,840 Speaker 1: Welcome to Brainstuff from house Stuff works dot com where 2 00:00:03,840 --> 00:00:14,960 Speaker 1: smart happens. Hi. I'm Marshall Brain with today's question, how 3 00:00:14,960 --> 00:00:17,880 Speaker 1: do carbohydrates work and why do we hear about them 4 00:00:17,880 --> 00:00:21,280 Speaker 1: all the time? In the news? Carbohydrates are something we 5 00:00:21,320 --> 00:00:26,080 Speaker 1: hear about constantly in American culture. There are simple carbohydrates 6 00:00:26,079 --> 00:00:30,360 Speaker 1: and complex carbohydrates, where complex carbohydrates are supposed to be 7 00:00:30,360 --> 00:00:33,239 Speaker 1: better for your health than the simple ones. There are 8 00:00:33,320 --> 00:00:36,960 Speaker 1: low carb diets like the Atkins diet or the Ducan diet, 9 00:00:37,440 --> 00:00:40,040 Speaker 1: and they're supposed to help you lose lots of weight 10 00:00:40,080 --> 00:00:44,640 Speaker 1: by somehow eliminating the bad effects of carbohydrates. Then there's 11 00:00:44,680 --> 00:00:48,680 Speaker 1: the more esoteric things like the glycemic index of foods, 12 00:00:48,960 --> 00:00:51,720 Speaker 1: and this has to do with carbohydrates as well. Let's 13 00:00:51,720 --> 00:00:54,680 Speaker 1: take a look at how carbohydrates work and why you 14 00:00:54,720 --> 00:00:58,560 Speaker 1: should care about them. You've probably heard of things like 15 00:00:58,680 --> 00:01:03,800 Speaker 1: glucose and pctoes. These are the simplest carbohydrates. They are 16 00:01:03,920 --> 00:01:08,840 Speaker 1: molecules containing six carbon atoms, six oxygen atoms, and twelve 17 00:01:08,920 --> 00:01:12,520 Speaker 1: hydrogen atoms, and this is where the name carbohydrate comes from. 18 00:01:12,880 --> 00:01:17,600 Speaker 1: Carbo represents the carbon atoms, while the oxygen and hydrogen 19 00:01:17,680 --> 00:01:23,360 Speaker 1: atoms represent water or hydrates. Plants make carbohydrates from sunlight, 20 00:01:23,440 --> 00:01:27,880 Speaker 1: and animals eat the plants. Pure glucose or pure fructose, 21 00:01:28,200 --> 00:01:32,160 Speaker 1: being the simplest carbohydrates, can be immediately absorbed by the 22 00:01:32,240 --> 00:01:36,800 Speaker 1: small intestine into the bloodstream. Table sugar or sucrose is 23 00:01:36,840 --> 00:01:41,440 Speaker 1: a die sacc ride. One glucose and one fructose molecule 24 00:01:41,560 --> 00:01:45,280 Speaker 1: are bonded together to make a molecule of sucrose. And 25 00:01:45,560 --> 00:01:48,520 Speaker 1: enzyme in your small intestine can break the pair apart 26 00:01:48,880 --> 00:01:51,440 Speaker 1: and then they can be immediately absorbed in your small 27 00:01:51,480 --> 00:01:55,520 Speaker 1: intestine and they enter the bloodstream. A starch, like the 28 00:01:55,560 --> 00:01:59,080 Speaker 1: starch found in wheat or potatoes or rice, is a 29 00:01:59,200 --> 00:02:03,520 Speaker 1: longer chain of glucose molecules connected together. Your body has 30 00:02:03,640 --> 00:02:07,280 Speaker 1: enzymes that can break apart the chain into individual glucose 31 00:02:07,320 --> 00:02:12,160 Speaker 1: molecules for absorption. Starch molecules are known as complex carbohydrates, 32 00:02:12,200 --> 00:02:15,040 Speaker 1: and this is where the idea of the glycemic index 33 00:02:15,120 --> 00:02:19,280 Speaker 1: comes from. In general, things like glucose and table sugar 34 00:02:19,400 --> 00:02:22,800 Speaker 1: come into your body and enter the bloodstream very very quickly. 35 00:02:23,320 --> 00:02:26,440 Speaker 1: They have a high glycemic index and cause a spike 36 00:02:26,560 --> 00:02:30,000 Speaker 1: in the amount of glucose in your bloodstream. White bread, 37 00:02:30,120 --> 00:02:33,320 Speaker 1: because the wheat is so highly processed, also has a 38 00:02:33,400 --> 00:02:38,520 Speaker 1: high glycemic index. Whole grains, beans, nuts, and vegetables do 39 00:02:38,639 --> 00:02:43,200 Speaker 1: contain carbohydrates, but these carbohydrate chains take much longer to 40 00:02:43,200 --> 00:02:46,480 Speaker 1: break down in the small intestine, so the glucose from 41 00:02:46,520 --> 00:02:49,960 Speaker 1: these foods enters the bloodstream much more slowly and evenly. 42 00:02:50,480 --> 00:02:54,079 Speaker 1: These foods have a low glycemic index and therefore are 43 00:02:54,200 --> 00:02:58,120 Speaker 1: much healthier because they don't cause such intense spikes in 44 00:02:58,200 --> 00:03:02,200 Speaker 1: blood sugar. Many diet it's are low carb diets. They 45 00:03:02,240 --> 00:03:05,400 Speaker 1: ask you to restrict the carbohydrates you eat. Why do 46 00:03:05,480 --> 00:03:09,000 Speaker 1: they do that? Keep in mind that what a typical 47 00:03:09,120 --> 00:03:12,680 Speaker 1: American diet looks like is things like a bowl of 48 00:03:12,760 --> 00:03:16,239 Speaker 1: cereal or a slice of pizza, or a can of ravioli, 49 00:03:16,360 --> 00:03:20,679 Speaker 1: or a bottle of soda, potato chips, packages of cookies, 50 00:03:20,720 --> 00:03:23,840 Speaker 1: bowls of ice cream. These are common foods in the 51 00:03:23,880 --> 00:03:28,680 Speaker 1: typical American diet. These foods typically contain something like forty 52 00:03:28,720 --> 00:03:32,880 Speaker 1: to fifty grams of carbohydrates per serving. Therefore, a typical 53 00:03:32,880 --> 00:03:37,040 Speaker 1: American eating a typical American diet can easily consume three 54 00:03:37,160 --> 00:03:40,640 Speaker 1: hundred grams of carbs per day or more without even 55 00:03:40,680 --> 00:03:44,480 Speaker 1: thinking about it. A lunch consisting of two slices of pizza, 56 00:03:44,600 --> 00:03:48,240 Speaker 1: chocolate chip cookie, and a big soda. That's two hundred 57 00:03:48,280 --> 00:03:51,240 Speaker 1: grams of carbs right there, and it all comes in 58 00:03:51,240 --> 00:03:53,800 Speaker 1: in just a few minutes. The surge of glucoast that 59 00:03:53,880 --> 00:03:57,120 Speaker 1: a meal like this pumps into the bloodstream requires your 60 00:03:57,120 --> 00:03:59,800 Speaker 1: body to use a lot of insulin to handle the spike. 61 00:04:00,240 --> 00:04:03,640 Speaker 1: Over the years, the spikes can cause type two diabetes, 62 00:04:03,680 --> 00:04:06,560 Speaker 1: where your body becomes resistant to the effects of the 63 00:04:06,600 --> 00:04:10,360 Speaker 1: insulin that your pancreas is putting into the bloodstream. In addition, 64 00:04:10,600 --> 00:04:13,480 Speaker 1: a meal like that contains a lot of calories, leading 65 00:04:13,520 --> 00:04:16,320 Speaker 1: to obesity over time, and that causes its own set 66 00:04:16,320 --> 00:04:20,880 Speaker 1: of health effects. A low carb diet restricts your carbohydrate intake, 67 00:04:21,080 --> 00:04:24,719 Speaker 1: say fifty grams of carbs per day rather than three hundred. 68 00:04:25,240 --> 00:04:28,840 Speaker 1: This restriction can decrease the spikes in blood sugar, which 69 00:04:28,839 --> 00:04:31,880 Speaker 1: tends to lower hunger pangs and reduce the calories you 70 00:04:31,920 --> 00:04:35,600 Speaker 1: consume per day. Will a low carb diet hurt you? 71 00:04:35,880 --> 00:04:38,360 Speaker 1: For example, you may know that your brain and nervous 72 00:04:38,360 --> 00:04:42,360 Speaker 1: system require glucose. If you take in no carbohydrates, will 73 00:04:42,400 --> 00:04:47,160 Speaker 1: your brain die No. Your body, when necessary can manufacture 74 00:04:47,200 --> 00:04:50,440 Speaker 1: its own carbohydrates in your liver through a process called 75 00:04:50,800 --> 00:04:55,839 Speaker 1: gluco neogenesis. This process is important if say, you're lost 76 00:04:55,880 --> 00:04:58,520 Speaker 1: in a forest with no food for three days, or 77 00:04:58,560 --> 00:05:01,480 Speaker 1: if you're fasting for some reason, or if you get 78 00:05:01,560 --> 00:05:04,159 Speaker 1: so sick that you can't eat for a few days, 79 00:05:04,440 --> 00:05:07,680 Speaker 1: or if you're living in an extremely cold climate and 80 00:05:07,760 --> 00:05:10,920 Speaker 1: meat is your only source of food. In all those cases, 81 00:05:10,960 --> 00:05:14,120 Speaker 1: there's no glucose coming in, so obviously your body has 82 00:05:14,160 --> 00:05:16,960 Speaker 1: to have a way to deal with it. Glucose is essential, 83 00:05:17,120 --> 00:05:19,800 Speaker 1: so your body is able to supply the glucose even 84 00:05:19,839 --> 00:05:22,880 Speaker 1: if you have no carbohydrates coming in through your food. 85 00:05:23,680 --> 00:05:27,400 Speaker 1: This whole thing is fascinating really. Carbohydrates are one source 86 00:05:27,440 --> 00:05:30,839 Speaker 1: of food energy, but there are all these different aspects 87 00:05:30,880 --> 00:05:34,000 Speaker 1: to it, and carb consumption can have a huge impact 88 00:05:34,040 --> 00:05:37,320 Speaker 1: on your overall health. The more you learn about carbohydrates, 89 00:05:37,360 --> 00:05:41,800 Speaker 1: the more interesting it gets. 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