Is sugar really bad for you?糖真的有害健康么？ 时间:2018-10-30 单词数:5990
双语 中文 英文
It’s hard to imagine now, but there was a time when humans only had access to sugar for a few months a year when fruit was in season. Some 80,000 years ago, hunter-gatherers ate fruit sporadically and infrequently, since they were competing with birds.
Now, our sugar hits come all year round, often with less nutritional value and far more easily – by simply opening a soft drink or cereal box. It doesn’t take an expert to see that our modern sugar intake is less healthy than it was in our foraging days. Today, sugar has become public health enemy number one: governments are taxing it, schools and hospitals are removing it from vending machines and experts are advising that we remove it completely from our diets.
But so far, scientists have had a difficult time proving how it affects our health, independent of a diet too high in calories. Meanwhile, there is also a growing argument that demonising a single food is dangerous – and causes confusion that risks us cutting out vital foods.
But both complex and simple carbohydrates are made up of sugar molecules, which are broken down by digestion into glucose and used by every cell in the body to generate energy and fuel the brain. Complex carbohydrates include wholegrains and vegetables. Simple carbohydrates are more easily digested and quickly release sugar into the bloodstream. They include sugars found naturally in the foods we eat, such as fructose, lactose, sucrose and glucose and others, like high fructose corn syrup, which are manmade.
But again, it’s unclear if that means sugar actually causes heart disease or diabetes. Luc Tappy, professor of physiology at the University of Lausanne, is one of many scientists who argue that the main cause of diabetes, obesity and high blood pressure is excess calorie intake, and that sugar is simply one component of this.
“More energy intake than energy expenditure will, in the long term, lead to fat deposition, insulin resistance and a fatty liver, whatever the diet composition,” he says. “In people with a high energy output and a matched energy intake, even a high fructose/sugar diet will be well tolerated.”
Tappy points out that athletes, for example, often have higher sugar consumption but lower rates of cardiovascular disease: high fructose intake can be metabolised during exercise to increase performance.
Overall, evidence that added sugar directly causes type 2 diabetes, heart disease, obesity or cancer is thin. Yes, higher intakes are associated with these conditions. But clinical trials have yet to establish that it causes them.
Sugar also has been associated with addiction… but this finding, too, may not be what it seems. A review published in the British Journal of Sports Medicine in 2017 cited findings that mice can experience sugar withdrawal and argued that sugar produces similar effects to cocaine, such as craving. But the paper was widely accused of misinterpreting the evidence. One key criticism was that the animals were restricted to having sugar for two hours a day: if you allow them to have it whenever they want it, which reflects how we consume it, they don’t show addiction-like behaviours.
Still, studies have demonstrated other ways in which sugar affects our brains. Matthew Pase, research fellow at Swinburne’s Centre for Human Psychopharmacology in Australia, examined the association between self-reported sugary beverage consumption and markers of brain health determined by MRI scans. Those who drank soft drinks and fruit juices more frequently displayed smaller average brain volumes and poorer memory function. Consuming two sugary drinks per day aged the brain two years compared to those who didn’t drink any at all. But Pase explains that since he only measured fruit juice intake, he can’t be sure that sugar alone is what affects brain health.
01Chinese President Xi Jinping opens world’s longest sea-crossing bridge10.25习近平宣布：港珠澳大桥正式开通
02Former CCTV anchorman Li Yong dies at age 5010.29前央视主持人李咏去世，享年50岁
03Chinese seniors easy victims of fake online news: statistics10.28是倍感孤独还是文化不足？为什么中国的老人易轻信网络谣言
04Expansive New Study Says Not Exercising Is Worse for Your Health Than Smoking10.24研究表明不运动比吸烟健康危害还要大
05World’s longest sea bridge to open ... but only to drivers with a special permit 10.24习主席宣布港珠澳大桥开通，绝美大片先睹为快
06Are you kidding? Chinese parents furious over 12-page holiday assignment on fallen leaves 10.24奇葩作业让家长抓狂：要求一年级孩子写12页报告
07Curse of the lottery: Why winning the Mega Millions could kill you 10.29彩票中了大奖是否就是开启了美丽人生？美国博彩中奖者命运却如此悲惨
08Why you don’t really have a type?10.24审美会一直变化，所以你一直没有“喜欢的类型”？
09Group in China earns nearly a dozen retractions for image duplication, forged authorship, and more10.24清华回应11篇论文被海外撤稿：撤销造假者博士学位
10China denies report it spies on Trump’s iPhone, suggests he get a Huawei instead10.27《纽约时报》称中俄窃听特朗普iPhone 华春莹：建议改用华为