Herbal teas often
take a toll on teeth
Many people forgo caffeinated teas and coffee in favor of herbal teas, expecting health benefits. But the change may not be the best for dental health.
Both black and green tea, although they can stain teeth, are good natural sources of fluoride and contain tannins that inhibit the growth of bacteria associated with tooth decay.
Many herbal teas, however, may actually increase tooth decay. Researchers Judith Phelan and Jeremy Rees at the University of Bristol Dental School published a study on herbal teas in this month's Journal of Dentistry. Their results may surprise you.
Question: What types of tea were studied?
Answer: The researchers tested a variety of teas commonly consumed in the United Kingdom. These included standard black tea, chamomile and a variety of herbal blends with names such as echinacea and raspberry; black currant, ginseng and vanilla; raspberry, cranberry and elderflower; peach and passionfruit. For comparison, they also included lemon-flavored Lipton ice tea and orange juice.
Q: How were the teas tested?
A: The loss of enamel in tooth decay is caused by exposure to acids. Acids can come from plaque bacteria that grow on the surface of teeth when they are well fed on sugars. Acids also are naturally present in foods and can directly erode tooth enamel.
This study focused on the effects of the natural acids in the drinks. The acidity of each drink was measured, and sections of extracted human teeth were soaked in each beverage for one hour.
Q: How were teeth affected?
A: With the exception of black and chamomile teas, the herbal teas caused erosion of tooth enamel similar to or worse than orange juice, an acidic beverage. Some blends caused almost three times as much erosion as orange juice. Chamomile and black teas caused virtually no erosion.
Q: Does this mean that most herbal teas should be avoided?
A: Not necessarily. Many healthy beverages and foods such as fruits have similar acid levels. Also, test-tube study conditions are not identical to conditions in the mouth.
However, herbal teas consumed as a main beverage many times per day for several years could damage tooth enamel and lead to increased tooth decay over time. For long-term dental health, it is good practice to swish the mouth with water after eating food or drink that is high in acid or sugar.
Although herbal teas are perceived as more healthy, regular black or green teas are better choices for dental health. Unlike herbal tea blends, chamomile tea is not erosive to the teeth.
Again, the bottom line is moderation and variety -- even when it comes to teas.
Alan Titchenal, Ph.D., C.N.S. and Joannie Dobbs, Ph.D., C.N.S. are
nutritionists in the Department of Human Nutrition, Food and Animal
Sciences, College of Tropical Agriculture and Human Resources, UH-Manoa.
Dr. Dobbs also works with the University Health Services and prepares
the nutritional analyses marked with an asterisk in this section.