Thursday, August 11, 2011

When wine meets your teeth


You may remember that a couple of issues ago Warwick Boardman asked about the pH of wine. I though I would give you a brief update. You see, Warwick had asked a question I didn’t know the answer to, and that upsets the equilibrium of my brain, so it was off the Medical Library for me.
  
pH of wine
First, a real quick reminder. It is the low pH levels (high acidity) of soft drinks, fruit juice and sports drinks that is the most likely to cause tooth enamel erosion, not the sugar content. For more, see my  blog here.

What about the pH of a social and relaxing glass of wine? I like the commitment of the German researchers who analysed the pH of 50 white wines and 50 red wines (ref 1). They found that they range from 3.0 - 3.9 for white wine and 3.4 – 4.1 for red wine, which makes acidic, although less acidic than soft drinks and fruit juices which have a pH commonly around 2.3 – 3.2.

Just based on those figures you could guess that white wine, generally, had the greater potential to cause tooth enamel erosion. You would be correct. Exposing extracted human teeth to wine found that white wine caused more calcium release from teeth than red wine. Note that this study was done with extracted teeth dropped into a beaker of wine. It did not take into account the buffering effect of saliva or food that might be present in the mouth of a consumer.

Saliva
An Australian study looked at the buffering effect of saliva after drinking wine (ref 2). They found that saliva was “relatively ineffective” at neutralising the acid because the pH in the mouth remained low enough, for long enough, after drinking wine for enamel to start to dissolve. Pity, because I always thought that saliva would be helpful.

Quick tip. Don’t clean your teeth straight after consuming acidic drinks. You might think that helps avoid erosion. It doesn’t. Any micro-damage from the acid will occur quickly. Allow time for your saliva to remineralise your teeth. That’s a critical function of saliva. It’s not just for licking the occasional envelope. Wait, say, for an hour between drinking and brushing your fangs.

Wine tasters
Already you have been thinking: “What about wine tasters?” An enviable occupation, that’s for sure. Some of these folk will be tasting 20 – 100 wines a day, maybe more, and the wine can stay in the mouth for some time. Yes, there have been reported cases of the teeth of wine tasters being affected by wine. One wine taster had tasted at least 20 wines a day for 10 years and had a five year history of tooth sensitivity to hot and cold food (ref 3). A 56 year young lady who drank a bottle of wine a day for 34 years also presented to her dentist with tingly teeth (ref 4). Yep, the acidity of wine can be a problem for frequent wine consumers.

What does it all mean?
Like any drink with a low pH, don’t let wine wash around your teeth for too long. A glass each day is unlikely to be a problem, but if you enjoy half a bottle or more at dinner every day then your teeth (and liver) might complain down the track. The same goes for juice, soft drinks and sports drinks – some OK, but if you drink them in the litres each day, make sure you see your dentist regularly. Or try drinks closer to neutral pH, like water or milk. Old fashioned, I know, but we have been consuming them for centuries with good results.

Right now I’m looking for research funds to determine the pH of reds bottled in the 1960s and 1970s. If you could help out with either funds or the bottles I would be gratefully smashed.

References: 
1. Nutrition Research 2009; 29: 558-567
2. Australian Dental Journal 2009; 54: 228-232
3. Australian Dental Journal 1998; 43: 32-34
4. Journal of the American Dental Association 2005; 136: 71-75

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