萨里大学的一项开拓性研究发现,健康成人在高糖膳食后,血液中的脂肪含量会增加,大量脂肪会储存在肝脏。
这项研究已经发表在《临床医学》杂志上。研究人员希望通过这项研究来确定肝脏中脂肪的含量是否会影响糖对心血管健康的作用。实验观察2组人群,这些人肝脏中的脂肪含量有的高有的低,实验人员为他们提供高糖膳食或低糖膳食。其中低糖膳食中糖提供的能量不超过140千卡——这个量接近推荐摄入量,高糖膳食中糖分提供650千卡。(译者注:每1克糖提供4千卡能量。低糖膳食140千卡约为35克糖,高糖膳食650千卡约为162.5克糖。这个量实际上一般成人饮食是达不到的,文章最后专家也有提到需要注意的地方。世界卫生组织强烈建议每日游离糖摄入不超过50克,推荐不超过25克)
12周的高糖膳食之后,这些人肝脏脂肪含量变高——这种情况被称为非酒精性脂肪肝(NAFLD),这表示他们的脂肪代谢发生了改变,这种改变意味着他们心血管疾病、心脏病和中风的风险都增加了。
上文提到的脂肪代谢,是一种体内的生物化学过程,在这个过程中脂肪会被运输并在血液中分解,最终被身体的细胞利用。
实验结果还显示,体内肝脏中脂肪含量水平较低的健康成人,如果长期进行高糖膳食,他们肝脏中的脂肪含量也会增加,并且他们的脂肪代谢也会和那些患非酒精性脂肪肝人群的脂肪代谢变得相近。
营养代谢专家Bruce Griffin介绍:“我们的研究提供了新的证据,证明摄入大量糖会改变身体的脂肪代谢,并因此增加心血管疾病的风险。当然,大多数的成人并不会摄入像我们实验中如此大量的糖分,不过一些儿童和青少年可能会因为过量摄入汽水和甜食而达到这个糖分摄入水平。这增加了我们对年轻人未来健康状态的担忧,特别是考虑到如今的情况:儿童和青少年令人担忧的高非酒精性脂肪肝患病率和成年人群患致命肝病的人数在指数上升。”
Too much sugar? Even 'healthy people' are at risk of developing heart disease
A ground-breaking study from the University of Surrey found that a subject group of otherwise healthy men had increased levels of fat in their blood and fat stored in their livers after they had consumed a high sugar diet.
The study, which has been published inClinical Science, looked at two groups of men with either high or low levels of liver fat, and fed them a high or low sugar diet to find out if the amount of liver fat influences the impact of sugar on their cardiovascular health. The low sugar diet contained no more than 140 calories a day worth of sugar -- an amount close to the recommended intake -- while the high sugar diet contained 650 calories worth.
After 12 weeks on the high sugar diet, the men with a high level of liver fat -- a condition known as non-alcoholic fatty liver disease (NAFLD) -- showed changes in their fat metabolism that are associated with an increased risk of cardiovascular disease, heart attacks and strokes.
Fat metabolism is the biochemical process by which fats are transported and broken down in the blood, and used by the cells of the body.
The results also revealed that when the group of healthy men with a low level of liver fat consumed a high amount of sugar, their liver fat increased and their fat metabolism became similar to that of the men with NAFLD.
Professor of Nutritional Metabolism, Bruce Griffin, said: "Our findings provide new evidence that consuming high amounts of sugar can alter your fat metabolism in ways that could increase your risk of cardiovascular disease.
"While most adults don't consume the high levels of sugar we used in this study, some children and teenagers may reach these levels of sugar intake by over-consuming fizzy drinks and sweets. This raises concern for the future health of the younger population, especially in view of the alarmingly high prevalence of NAFLD in children and teenagers, and exponential rise of fatal liver disease in adults."