延缓衰老的又一注意事项！
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Sugar-It Could Age You Rats that eat high levels of a natural sugar known as fructose seem to age faster than other rats--and the same could be true for people who eat too much sweet junk food, Israeli researchers said Monday. Fructose, found naturally in honey and fruit, is used widely in foods ranging from soft drinks to yogurt. But while its sweet taste is popular, the sugar could cause wrinkles and heal the problems, the researchers said. Dr. Moshe Werman and Boaz Levi of the Technion-Israel Institute of Technology fed large amounts of fructose to laboratory rats. Writing in the Journal of Nutrition, they said the fructose-fed rats showed changes n the collagen of their skin and bones. Collagen, a fibrous protein found in connective tissue, bone and cartilage, basically holds the body together. The loss of collagen is what causes sagging and deep wrinkles in older people. The process affected, Werman’s team said, is known as "cross linking". "Too much cross-linking reduces elasticity and makes the skin stiff and rigid, and these are the conditions that encourage wrinkled skin," Werman said in a statement. He said the same could be true of people, although this has not been shown. "Americans are eating more and more processed foods such as carbonated drinks, baked goods, canned fruits, jams and dairy products that contain fructose," Werman said. Other studies have shown that high fructose intake can affect how the body handles glucose and increases insulin resistance---- which can both be important measures of the tendency toward diabetes. The rats Werman worked with were fed much more than the average adult person might eat in a day, which is standard in such experiments. The rats were fed 12.5 grams of fructose per kg (2.2 pounds) of weight every day for a year. To compare, a person weighing 154 pounds (70kg) who drinks a quart (liter) of cola consumes about 60 grams of fructose, or 0.8 grams per kg of body weight. 以色列的研究人员星期一说，大量摄取一种叫做果糖的天然糖的老鼠，似乎比其他老鼠衰老的更快。对甜食吃得太多的人来说，情况也可能会是如此。 自然存在于蜂蜜和水果中的果糖，被广泛用于从饮料到酸奶的各种食品中。研究人员说，尽管它的甜味很受欢迎，这种糖却能使皮肤起皱纹并影响身体健康。以色列科学技术研究所的摩西- 沃曼和波阿兹-利位博士喂给实验鼠大量果糖。他们在《营养学杂志》上发表文章说，那些吃了果糖的老鼠的皮肤和骨质中的胶原蛋白发生了变化。 胶原蛋白是存在于结缔组织、骨质和软骨中的纤维蛋白质，它的基本作用是将人体各组织结合在一起。胶原蛋白的丧失是导致老年人皮肤松弛和深度皱纹的原因。 沃曼领导的研究小组把胶原蛋白的丧失引起的生理变化称作"交叉相联"。沃曼在一次报告中说："太多的’交叉相联’就会使皮肤降低弹性，发生硬化，这是导致皮肤起皱纹的原因。"他说，人也可能是如此，尽管还没有证据证明这一点。他又说："美国人摄取的加工食品越来越多，例如碳酸饮料、烘烤食品、罐装水果、果酱和乳制品，而这些食品都含有果糖。"其他的一些研究已经表明，大量摄取果糖会影响人体对葡萄糖的代谢和增强对胰岛素的抵抗力，而这两者是判断患糖尿病可能性的重要指标。 沃曼喂养的老鼠摄取的果糖比普通成人每天可能摄取的果糖多的多，这在此类实验中是符合标准的。在一年的时间里，这些老鼠每天按每千克（2.2磅）体重12.5克的标准摄取果糖。与此相比，一个体重154磅（70千克）的人，喝一夸脱（升）的可乐，大约摄取了60克的果糖，或者说每千克体重摄取0.8克的果糖。 |
