Dentists have long lamented the habits of their wine-loving patients. It was in 1907 that W.D. Miller, a pioneering dentist and scientist, first suggested that drinking wine might lead to tooth erosion. Since then, several studies have bolstered anecdotal evidence that alcohol in general, and wine specifically, can dissolve tooth enamel. The most recent of these studies examines the dental implications of acute alcohol consumption—that is, alcohol consumed on a single occasion—and explores the differences among wine, beer and whisky.
A wine's acidity is the leading suspect in damage to enamel. Composed mainly of a basic salt called hydroxyapatite, enamel begins to dissolve when acidity lowers the pH in your mouth below a critical point, somewhere between 5 and 5.7. Meanwhile, wine’s malic, tartaric, lactic, succinic and citric acids usually contribute to a pH of between 2.9 and 3.5.
But how do wine’s effects on teeth compare to those of other acidic beverages, especially other acidic alcohols? That was the question taken up by researchers from Griffith University in Australia and three Indian dental schools for a study recently published in Oral Health and Dental Management. For their investigation, the team collected saliva samples from subjects before and after alcohol consumption. One-third each of the study’s subjects consumed wine, beer and whisky, respectively, in volumes proportionate to their body weights. (Sample size was small in this pilot study—36 subjects, all healthy men between 25 and 30 years of age.)
Researchers then analyzed the saliva samples for levels of acidity, ionic calcium and inorganic phosphate. When enamel begins to dissolve, calcium and phosphate ions are released. Theoretically, therefore, the levels of calcium and phosphate should correlate with enamel dissolution.
“There was a significant reduction in mean salivary pH after consumption of any form of alcohol,” the study’s lead author, Dr. Santosh Kumar, told Wine Spectator. “The highest reduction was caused by beer, followed by whisky and wine.” The whisky group showed a higher calcium concentration, while increased phosphate levels appeared in both the whisky and wine groups. The fact that beer caused the largest spike in mouth pH but produced the lowest increases in calcium and phosphate, Kumar noted, “supports that erosive potential is not solely dependent on pH.”
Kumar suggested that in addition to pH, a beverage’s mineral content, titratable (or total) acidity, and its calcium binding properties can contribute to enamel dissolution. Dr. H.S. Brand, assistant professor of oral biochemistry at the Academic Centre for Dentistry Amsterdam, added that individuals’ reactions to acidic drinks may depend on the amount and composition of their saliva. “When somebody has a high amount of saliva present,” Brand explained, “saliva may dilute the drink, thereby reducing the pH.”
Wine tasters, who swirl and swish before spitting or swallowing, are at greater risk for dental damage. The longer you keep wine in your mouth, and the more aggressively you rinse it around your teeth, the greater your exposure to acid. Kumar’s study found that a single occasion of drinking could measurably affect tooth enamel; indeed, Brand reported that pH levels remain “significantly decreased for several minutes” after a wine taster spits.
So how can you prevent damage, if you are determined to keep wine in your mouth long enough to truly taste it? Brand recommends following your tasting with a swig of water or milk, which have neutral pH. “Wine tasters should not brush their teeth immediately after tasting,” he added. Post-tasting, wait one hour before brushing so as not to aid the erosion process of the already-softened enamel. Consider using fluoride varnish, and invest in a toothpaste that is low-abrasive and contains remineralizing agents. Finally, don’t go to bed with wine-coated teeth.
But Brand emphasized that wine may lead to erosion for only the most prolific tasters. “My guess is that this effect will be rather limited in the general population,” he said, noting that acidic, carbonated soft drinks are more likely to cause widespread problems, due to their higher volume of consumption.