“Red wine can care for our teeth”, the Daily Express reported. The newspaper says that “a daily glass could help keep teeth healthy and reduce the need for fillings.”
This news report is based on a laboratory study investigating the effects that red wine (stripped of its alcohol) had on one type of bacteria that causes tooth decay. The results suggest that chemicals in red wine can stop bacteria sticking to extracted teeth in a petri dish, but this does not necessarily mean that drinking red wine will reduce the risk of cavities. It is possible that other components in the wine, such as sugars and acids, could counteract the effects, or that the wine does not remain in the mouth long enough.
Although this type of research might lead to the discovery of a chemical that might be useful in a toothpaste, it is unlikely that drinking red wine will ever be suggested by dentists as a good way to protect your teeth.
Where did the story come from?
The research was carried out by Dr Maria Daglia and colleagues from Pavia University and other universities in Italy. The study was funded by the Italian Ministry for Research and Universities. It was published in the peer-reviewed journal Food Chemistry.
What kind of research was this?
This laboratory study investigated the effect of de-alcoholised red wine on the growth of the bacteria that cause tooth decay.
Although this study can illustrate the effects of de-alcoholised red wine in the laboratory, this does not necessarily prove that drinking red wine will prevent tooth decay in real life. It is possible that other components in the wine, such as sugars and acids, could counteract the effects. In addition, the wine may not spend long enough in the mouth to have these effects.
What did the research involve?
The researchers carried out various experiments involving one of the bacteria that leads to tooth decay, Streptococcus mutans. Firstly, they took an Italian red wine, Valpolicella Classico DOC Superiore, vintage 2003 (pH 3.56, alcohol 13.5%), and removed the alcohol.
They then looked at whether this de-alcoholised wine affected how the bacteria attached to saliva-coated beads made of a mineral called hydroxyapatite (called sHA beads). This mineral is found in teeth, and the beads are meant to provide a surface similar to that of a tooth that the bacteria can stick to. In the mouth, these bacteria stick to the surface of the tooth and begin to break down the hydroxyapatite, which can eventually result in a cavity. If a chemical can stop the bacteria from sticking to the tooth, then it could theoretically help prevent cavities. The researchers also investigated which chemicals within the wine had these effects.
Finally, the researchers looked at how de-alcoholised red wine affected the formation of a film of these bacteria on the surface of an extracted human tooth, which had been placed in a bacterial solution in the laboratory.
What were the basic results?
The researchers found that the de-alcoholised red wine made it more difficult for the bacteria to attach to the surface of the sHA beads. They found that the main component in the de-alcoholised red wine to have this effect was a group of chemicals called proanthocyanidins.
The researchers also showed that de-alcoholised red wine made it more difficult for the bacteria to attach and form a thin layer (a biofilm) on the surface of the extracted human tooth.
How did the researchers interpret the results?
The researchers conclude that their findings suggest that the ability of red wine to prevent tooth decay “may be another beneficial effect of the moderate consumption of red wine”.
Although this study can illustrate the effects of de-alcoholised red wine in the laboratory, laboratory conditions may not accurately reflect what really happens in the mouth. Therefore, this study does not necessarily prove that drinking red wine prevents tooth decay.
It is possible that other components in red wine, such as alcohol, sugars and acids, could counteract the antibacterial effects of the proanthocyanidins. In addition, the wine may not spend long enough in the mouth to have these effects in real life. These study results may also have differed if other red wines had been tested.
Although this type of research might lead to the discovery of a chemical that might be useful in a toothpaste, it is unlikely that dentists will ever suggest that drinking red wine is a good way to protect your teeth.
Links to the headlines
Red wine ‘good for your teeth’. The Daily Telegraph, December 3 2009
Red wine can care for our teeth. Daily Express, December 3 2009
Links to the science
Daglia M, Stauder M, Papetti A, et al. Isolation of red wine components with anti-adhesion and anti-biofilm activity against Streptococcus mutans.
Food Chemistry 2009; 119: 1182-1188