咖啡烘焙的时间越长，苯酚类物质的含量就越高。
多年来，科学家们一直怀疑喝咖啡有助于降低患阿尔茨海默病和帕金森病的几率。一项新的研究表明，事实可能的确如此，而且烤得越黑，效果越好。
在唐纳德·韦弗(Donald Weaver)博士的带领下，加拿大克莱姆比尔大脑研究所(Krembil Brain Institute)的科学家们对三种星巴克100%阿拉比卡速溶咖啡进行了比较。这三种咖啡分别是淡咖啡、深咖啡和无咖啡因黑咖啡。
在体外(玻璃皿)测试中，我们发现这两种黑暗烘焙法都能特别有效地防止蛋白片段淀粉样蛋白和tau凝结。大脑中这些碎片的聚集被认为是阿尔茨海默病和帕金森病的主要原因。
在被测试的咖啡中分析的所有化合物中，只有一种——一种被称为苯基林丹的物质——具有抗凝块作用。咖啡烘焙的时间越长，它所含的苯酚就越多，因此效果就越明显。有趣的是，含咖啡因和不含咖啡因的深色烘焙咖啡同样有效，表明咖啡因的含量无关紧要(尽管如此，印第安纳大学布卢明顿分校(Indiana University Bloomington)最近进行的一项研究表明，咖啡因对预防痴呆症有效)。
“这是第一次有人研究苯胺类药物如何与导致阿尔茨海默氏症和帕金森氏症的蛋白质相互作用，”罗斯·曼奇尼博士说。“下一步将是调查这些化合物的益处，以及它们是否有能力进入血液，或穿过血脑屏障。”
这项研究的一篇论文最近发表在《神经科学前沿》(Frontiers in Neuroscience)杂志上。
For years, scientists have suspected that drinking coffee helps lessen the chances of getting Alzheimer's and Parkinson's diseases. A new study indicates that this may indeed be the case, and that the darker the roast, the better it works.
Led by Dr. Donald Weaver, scientists at Canada's Krembil Brain Institute compared three types of Starbucks 100-percent Arabica instant coffee – light roast, dark roast, and decaffeinated dark roast.
In in vitro (glass dish) tests, it was found that the two dark roasts were both particularly effective at keeping the protein fragments beta amyloid and tau from clumping. The clumping of these fragments within the brain is believed to be a key cause of both Alzheimer's and Parkinson's.
Of all the compounds that were analyzed in the coffees tested, there was only one – a group known as phenylindanes – that had the anti-clumping effect. The longer a coffee is roasted, the greater the amount of phenylindanes it contains, thus the more potent the effect is. Interestingly, the caffeinated and decaffeinated dark roasts were equally potent, indicating that caffeine content is irrelevant (that said, a study recently conducted at Indiana University Bloomington suggests that caffeine is effective at warding off dementia).
"It's the first time anybody's investigated how phenylindanes interact with the proteins that are responsible for Alzheimer's and Parkinson's," says Dr. Ross Mancini, who (along with biologist Yanfei Wang) assisted Weaver in the research. "The next step would be to investigate how beneficial these compounds are, and whether they have the ability to enter the bloodstream, or cross the blood-brain barrier."
A paper on the study was recently published in the journal Frontiers in Neuroscience.