字幕列表 影片播放 列印英文字幕 As much as we hate to admit it, we all know that too much sugar is bad for our health – yet we still consume a lot of it. So... why do we love sugar? Back in the 1970s, researchers gave a group of one hundred babies three harmless solutions with different tastes; sweet, sour and bitter. After the sweet solution, the babies showed positive facial expressions – they smiled and licked their lips. But after the sour and bitter tastes they pursed their lips, wrinkled their noses and stuck out their tongues. Studies like this show newborns and infants have an innate preference for sweet tastes. We seek out energy-dense foods like sugar; because the sweet taste signals there’s lots of calories we can use to survive. On the flip side, sour and bitter tastes signal that we should avoid something–like rotting food or off-milk. So we’re kind of hardwired to love sugar. And today, we consume a lot more of it than ever before. For our ancestors, finding sugar wasn’t so easy – sugar from fruit was only available at harvest time, and honey was hard to access. In the 13th century, sugar made its way from Asia to Europe and it was considered an exotic spice. In the 16th century sugarcane plantations were established in Brazil and between the 18th and 19th centuries, sugar consumption in England increased by 1,500%. Over the past 50 years, the consumption of sugar has tripled worldwide. Sugar sells because it’s cheap and tastes good… it’s in the majority of processed foods we eat. But… some scientists say that sugar can be as bad for you as smoking or drinking a lot of alcohol. Here’s why. When you eat sugar, you have sweetness receptors on your tongue, and in your pancreas and intestines, that can sense two simple sugars: glucose and fructose. They’re found naturally in fruits, some vegetables and table sugar. They’re also added to soda, candy and a lot of processed foods. Your body likes glucose, your cells depend on it for energy. When it enters your body, your pancreas starts producing insulin and your brain understands you’re metabolising what you just ate. It tells your body that you’re less hungry. Fructose can only be metabolised by the liver. Because your body can’t use all that energy there’s more fatty calories for you to keep. And the way fructose talks to your brain can be deceiving. When you consume fructose without the goodness of fibre in fruit and vegetables, it interferes with the hormone leptin, which helps produce that feeling of being full. So you think you’re still hungry, and even though you’ve just had a lot of calories, you keep eating. And that’s not all. When these sugars hit the sweetness receptors on your tongue, they also light up the reward pathways in your brain. Neurotransmitters like dopamine are released and dopamine makes you feel really good. You feel sooo goooood that you just keep eating that donut. Eatin’ that donut. Ohhhh yeahhhh... I can’t help it! We love sugar because it creates this feedback loop. When you eat it you still feel hungry, and eating more of it feels so good. And we know this cycle of sugar is bad for our health. Your liver can happily process six to nine teaspoons of sugar a day. But… remember the average American consumes 22 teaspoons a day. Because of our overconsumption, sugar contributes to the intake of excess calories which can cause weight gain. Higher intakes of fructose have been strongly linked to the obesity epidemic, a rise in the level of type two diabetes and heart disease. But more research and clinical trials are needed to show that it does cause them. The only thing science can definitively say is caused by sugar is tooth decay. We love sugar because our brain and body has this response to it that we can’t really control. Cutting back on sweet stuff definitely helps your relationship with sugar – you won’t crave it as much. And the next time you want something sweet, remember that… you’re probably sweet enough. Hey guys – this episode is the first of three that I’m making about sugar. There was so much information out there and I have such a sweet tooth it couldn’t all fit into one episode. On Monday: Can you be addicted to sugar? See you then.