Now even fruit juices--those "healthy" alternative beverages for your children--may cause a not- so-healthy response in their teeth. A recent study shows that too much fruit juice could damage the enamel on your children's teeth and lead to decay, reports the Academy of General Dentistry.
An analysis of 532 juices was conducted to determine the amount of fluoride in these drinks. Manufacturers of ready-to-drink juices, frozen-concentrate juices, and juice-flavored drinks were contacted to determine how much fluoride was in their juices. The study concluded that more than half of the juices have more fluoride than is recommended.
"The problem with fluoride is that sometimes you could have too much of a good thing," explains William Chase, DDS, FAGD, spokesdentist of the Academy of General Dentistry. "The correct amount of fluoride can prevent cavities, but too much fluoride can lead to fluorosis, which causes damage to the enamel and even decay. Fluorosis is typically characterized by either a chalky white stain or a dark brown stain against a normal enamel."
Investigators of this study looked at the recommended doses of supplemental fluoride and determined which juices were above or below those amounts. The recommended dose of supplemental fluoride is between 0.30 and 0.70 parts per million. The results of the study, however, show that about 43 percent had concentrations above 0.70 parts per million, and 19 percent had fluoride concentrations above 1.00 parts per million. The good news is that 48 percent of the juices had concentrations below 0.30 parts per million.
"This is very revealing," says Dr. Chase, who has noticed an increase in fluorosis among the children in his own dental practice. "Although fluoride can also be found in drinking water and toothpaste, the fact that there's so much fluoride in some of these juices is startling."
Parents have been coming to his practice concerned about the chalky white marks on their children's teeth, especially the two front, upper teeth. Because of this study, Dr. Chase may begin recommending that children ages 5 years to 7 years drink less than a quart of fruit juice a day because these are the formative years of the development of enamel.
The study even differentiated which flavors of juice had the most fluoride. White grape juice had the highest concentrations of fluoride, with a mean value of 1.45 parts per million. The high fluoride content of grape juices was attributed to the use of an insecticide that contains fluoride. In contrast, grape juices prepared from grapes after the skin had been removed contained no detectable concentrations of fluoride. Thus, the authors concluded that grape skins appeared to have concentrated amounts of fluoride.
Tea, prune, cranberry, pear, red grape, cherry and apple-grape juice all had mean fluoride concentrations greater than 0.70 parts per million. Orange juices, lemonades, fruit nectars and pineapple juices usually, but not always, had lower fluoride concentrations.
There were wide variations in fluoride concentrations, ranging from 0.02 to 2.80 parts per million. The fluoride content of most juices and juice-flavored drinks correlated with the amount of fluoride in the water used to manufacture the product.
"Part of the problem is that the product labels of these juices contained no information about the large differences in fluoride concentrations between the juices," said Dr. Chase. "Manufacturers should label products with their fluoride content."
This would be a daunting task, however, because the same products usually have very different fluoride concentrations because they were manufactured at different sites.