咖啡是否是一种健康饮料？

Coffee as a Health Drink？ Studies Find Some Benefits

咖啡是否是一种健康饮料？

　　Coffee is not usually thought of as health food, but a number of recent studies suggest that it can be a highly beneficial drink. Researchers have found strong evidence that coffee reduces the risk of several serious ailments, including diabetes, heart disease and cirrhosis of the liver.

　　咖啡通常都不被看作一种健康饮料，但是近来一些研究表明咖啡可能是一种十分有益的饮料。研究人员已经在找到可靠的证据证实，咖啡可以降低许多严重疾病的患病风险，其中包括了糖尿病、心脏病和肝硬化。

　　Among them is a systematic review of studies published last year in The Journal of the American Medical Association, which concluded that habitual coffee consumption was consistently associated with a lower risk of Type 2 diabetes. Exactly why is not known, but the authors offered several explanations.

　　在所有的报告中有一篇去年刊登在美国医学会期刊上系统的研究报告。报告推断，习惯性的饮用咖啡可以一直降低II型糖尿病的患病机率。具体的原因还没有找到，但报告还是给出了一些解释。

　　Coffee contains antioxidants that help control the cell damage that can contribute to the development of the disease. It is also a source of chlorogenic acid, which has been shown in animal experiments to reduce glucose concentrations.

　　咖啡含有抗氧化剂，能够帮助控制导致疾病的细胞损害。咖啡还能提供绿原酸，绿原酸在动物实验中能够降低血糖浓度。

　　Caffeine, perhaps coffee's most famous component, seems to have little to do with it; studies that looked at decaffeinated coffee alone found the same degree of risk reduction.

　　咖啡因可能是咖啡含有的最知名的成分，但看起来却没什么作用。一项使用脱去咖啡因的咖啡所作的实验显示其也能达到同样的降低血糖浓度的效果。

　　Larger quantities of coffee seem to be especially helpful in diabetes prevention. In a report that combined statistical data from many studies, researchers found that people who drank four to six cups of coffee a day had a 28 percent reduced risk compared with people who drank two or fewer. Those who drank more than six had a 35 percent risk reduction.

　　大量饮用咖啡对预防糖尿病特别有效。在一项结合了许多统计数据的报告中，研究人员发现每天饮用4-6杯咖啡的人群比每天饮用2杯或更少咖啡的人群患病风险降低了28%.饮用超过6杯的人群患病风险更是降低了35%.

　　Some studies show that cardiovascular risk also decreases with coffee consumption. Using data on more than 27,000 women ages 55 to 69 in the Iowa Women's Health Study who were followed for 15 years, Norwegian researchers found that women who drank one to three cups a day reduced their risk of cardiovascular disease by 24 percent compared with those drinking no coffee at all.

　　一些研究表明咖啡也能减少患心血管疾病的风险。根据爱达荷妇女健康研究中心15年跟踪调查的27000多位55到69岁的妇女的数据，挪威的研究人员发现每天饮用1到3杯咖啡的妇女比完全不饮用咖啡的妇女患心血管疾病的比例下降了24%.

　　But as the quantity increased, the benefit decreased. At more than six cups a day, the risk was not significantly reduced. Still, after controlling for age, smoking and alcohol consumption, women who drank one to five cups a day - caffeinated or decaffeinated - reduced their risk of death from all causes during the study by 15 to 19 percent compared with those who drank none.

　　但是，饮用咖啡数量越多，好处越少。对于每天饮用6杯以上的人群，患病风险没有明显的下降。同时，在研究中，加上控制吸烟和饮酒，与完全不饮用咖啡的妇女相比，每天饮用1到5杯咖啡的妇女，无论是含咖啡因的还是脱去咖啡因的，她们因为各种原因导致的死亡风险可以降低15%到19%.

　　The findings, which appeared in May in The American Journal of Clinical Nutrition, suggest that antioxidants in coffee may dampen inflammation, reducing the risk of disorders related to it, like cardiovascular disease. Several compounds in coffee may contribute to its antioxidant capacity, including phenols, volatile aroma compounds and oxazoles that are efficiently absorbed.

　　调查结果刊登在5月份的美国临床营养学杂志上。报告表示，咖啡中的抗氧化剂可以抑制发炎，减少因发炎引起的其他疾病，比如心血管疾病。咖啡中的一些成分有助于咖啡的抗氧化能力，包括可以被有效吸收的苯酚、可挥发的芳香族化合物、唑。

　　In another analysis, published in July in the same journal, researchers found that a typical serving of coffee contains more antioxidants than typical servings of grape juice, blueberries, raspberries and oranges.

　　在该杂志7月出版的期刊上，研究人员的另一项研究中发现一份咖啡还有的抗氧化剂比一份葡萄汁、一份蓝莓汁、一份覆盆子汁和一份橙汁还要多。

　　"We were surprised to learn that coffee quantitatively is the major contributor of antioxidants in the diet both in Norway and in the U.S.A.," said Rune Blomhoff, the senior author of both studies and a professor of nutrition at the University of Oslo.

　　"我们都觉得很惊奇，在数量上，咖啡在美国和挪威的饮食中居然是主要的抗氧化剂的提供者，"两篇报道的高级作者奥斯陆大学的营养学教授茹·布洛莫说。

　　These same anti-inflammatory properties may explain why coffee appears to decrease the risk of alcohol-related cirrhosis and liver cancer. This effect was first observed in 1992. Recent studies,published in June in The Archives of Internal Medicine, confirmed the finding.

　　这些同样可以抑制发炎的物质可以解释为什么咖啡可以减少与酒精相关的硬化和肝癌了。这一效果实在1992年首先发现的。近来刊登在《内科学文献》期刊上的的研究结果证实了这一发现。

　　Still, some experts believe that coffee drinking, and particularly caffeine consumption, can have negative health consequences. A study published in January in The Journal of the American College of Cardiology, for example, suggests that the amount of caffeine in two cups of coffee significantly decreases blood flow to the heart, particularly during exercise at high altitude.

　　一些专家仍然相信喝咖啡，尤其是含有咖啡因的咖啡会造成不良的健康影响。比如说，刊登在1月份美国心脏病学会志上的一项研究结果认为，两杯咖啡中含有的咖啡因可以显著的减少流向心脏的血液，特别是在高纬度地区锻炼时。

　　Rob van Dam, a Harvard scientist and the lead author of The Journal of the American Medical Association review, acknowledged that caffeine could increase blood pressure and slightly increase levels of the amino acid homocysteine, possibly raising the risk for heart disease.

　　《美国医学会杂志》评论的主要作者哈佛大学科学家罗布·范·达姆承认，开咖啡因可能会增加血压并能轻微增加高半胱胺酸的水平，这可能会增加心脏病的发病风险。

　　"I wouldn't advise people to increase their consumption of coffee in order to lower their risk of disease," Dr. van Dam said, "but the evidence is that for most people without specific conditions, coffee is not detrimental to health. If people enjoy drinking it, it's comforting to know that they don't have to be afraid of negative health effects."