【英语时差8,16】蜂蜜和蛀牙(在线收听

 
   Honey from Brazilian honeybees might help prevent cavities? In this Moment of Science Don tells Yael about that possibility.   
D: Well, see you later, Yael. I'm on my way to Brazil.
 
Y: I didn't know you were going to Brazil, Don. What's the occasion?
 
D: Honeybees.
 
Y: Honeybees?
 
D: Honeybees make a substance called propolis that researchers have good reason to   believe will prevent plaque from building up on our teeth, as well as possibly   preventing cavities. They've tested it on rats since they form cavities the same way   that humans do, and the results were that the cavity rate in these rats was cut by  about 60%. On top of that, the propolis nearly halted the activity of key enzymes in  forming dental plaque.
 
Y: I thought you said all honeybees make propolis, so why do you need to go to Brazil?
 
D: Because not all propolis is alike. Honeybees make propolis by collecting the  secretions of trees and other plants where they live; thus the make-up of propolis  varies depending on the plant life around. Researchers have found the propolis of  Brazilian honeybees to be particularly potent when it comes to protecting teeth. Brazilian honeybee propolis contains two key compounds, one of which is the best  plaque inhibitor scientists have ever seen. It is especially effective in blocking the      plaque action of the most common pathogen in our mouths, Streptococcus mutans. It  also blocks a particular enzyme that no other compound is known to inhibit. Even though it has not yet been proven to be effective in humans, propolis seems to be  pretty amazing stuff.
 
Y: So what are you going to do-get yourself stung to bits trying to get some of this stuff  to rub onto your teeth?
 
D: Not at all. I'm going to take a bee taming class while I'm there.  
  原文地址:http://www.tingroom.com/lesson/englishtimeover/341927.html