Leftovers from winemaking could be used in a new generation of dental plaque fighters.
How winemakers may help dentists. I'm Bob Hirshon and this is Science Update.
Wineries produce not only fine Cabernets, but may someday be a source of chemicals for dental rinses. This according to research at Cornell University and the University of Rochester. Cornell food scientist Olga Padilla-Zakour and her colleagues isolated chemicals called polyphenols from the squashed grape residue that wineries throw away. They tested the chemicals against bacteria that make the acids and dental plaque that cause tooth decay.
The polyphenol extracts inhibited the capacity of the bacteria to form the acids and also to produce the plaque.
But they didn't actually kill the bacteria. That's useful, because indiscriminate killing tends to breed drug-resistant germs. So it's possible that these chemicals could be part of a new generation of more sustainable antibiotics. I'm Bob Hirshon, for AAAS, the science society.
Making Sense of the Research
Tooth decay is among the most common diseases in the world. It's caused by certain strains of bacteria, including a type called Streptococcus mutans, which was studied in this experiment. In the presence of sugar, S. mutans produces acids that rot tooth enamel, as well as a sticky film called plaque which provides a protective home for the bacteria. Tooth decay can be prevented by avoiding sugar, brushing your teeth to remove the plaque, and getting rid of the acid-producing bacteria.
Right now, there isn't an especially good way to fight the bacteria directly. Mouthwashes and dental rinses can kill S. mutans, but they also kill other beneficial bacteria in your mouth. As a result, when bacteria re-colonize your mouth (within hours), the bad bacteria can get an even better toehold than before, because there's no competition from good bacteria. What's more, killing the bacteria outright helps breed resistant strains, because only those bacteria that are tough enough to survive go on to reproduce.
That's why this discovery seems especially promising. Of course, it's always great to find a scientific use for something that's normally just thrown away. In this case, though, the way that the wine residue chemicals work may be even more important than their source. As you heard, the chemicals disabled the bacteria's tooth decay-causing actions without killing them or interfering with their growth. If the disabled bacteria reproduce normally, there's no threat of breeding resistance.
All this doesn't mean that you should rinse your mouth with wine after brushing your teeth, since wine also contains acids that would outweigh any potential benefit from the bacteria-fighting chemicals. But in the future, the useful chemicals could be extracted from the wine waste and turned into a commercial mouthwash. This may turn out to be just one of many new drugs that take a less lethal, more sustainable approach to fighting germs.
Now try and answer these questions:
- How do bacteria like S. mutans cause tooth decay?
- How do the polyphenol chemicals in wine waste prevent this?
- What's important about the fact that the chemicals don't kill the bacteria?
- What other common medical and household products may be breeding resistant strains of bacteria? Are these products necessary?
You may want to check out the 2008 AAAS Annual Meeting Science Update Podcast to hear further information about this Science Update and the other programs for that week. This podcast's topics include: how sand spiders use elaborate camouflage, a new interactive map that tracks threats to the oceans, and four healthful habits of long-lived people.