Q. I know that a compound of fluorine, called a fluoride, is often added to some brands of toothpaste, and even to some water supplies to help reduce cavities. Does it really work for that?
A. Yes. Tooth decay rates are much higher than average in areas in which the drinking water is naturally low in fluorine. When adequate amounts of fluoride are incorporated into tooth enamel, the rate of tooth decay is substantially reduced. Studies show that it works not only for children's teeth, but for adults, too.
Q. Then why do some people get so upset over the fluoridation of water?
A. Mainly because they don't really understand what is being done. There is no question of adding abnormal amounts of fluorine - just of topping up abnormally low amounts. However, some people insist they can get all the fluoride they need from toothpaste or mouthwash. And some believe, perhaps with good reason, that not all of fluoride's possible long-term risks are known. A recent study, for instance, suggests that sodium fluoride, the compound that is usually added to water supplies, enhances the body's uptake of aluminum, a metal which some researchers suggest may be linked with the development of Alzheimer's disease. The consensus view, however, seems to be that this is not a significant risk
Q. Someone told me fluoride may cause cancer. Is that true?
A. No one knows for sure. A i 991 report by a committee convened by the US. National Toxicology Program to try to clear up the fluoride question, found 'equivocal' evidence linking fluoride to cancer. Some experts say that studies examining fluoride's potential cancer risk show that the risk is small. Others say the results provide clear evidence that fluoride causes cancer.
Q. You said fluoride is involved in bone health. Is it ever used to treat bone diseases such as osteoporosis?
A. Yes, sodium fluoride has been used experimentally, along with calcium, to promote the growth of new bone in people with osteoporosis. In fact, it does promote new bone growth, but some researchers worn/ that the new bone growth is too brittle to bear weight, and there is some research to support that concern, These researchers point out that fluoride is probably helpful for bones and teeth in small amounts, but in larger amounts becomes counterproductive.
Q. Is fluoride good for anything else?
A. Researchers have noted that people drinking fluoride-rich water have a lower incidence of soft-tissue calcification, a problem we talked about in the section on vitamin D. That means calcium is less likely to end up in their arteries, heart valves, tendons and other tissues, where it can harden tissues and make them malfunction.
FLUORINE
QUICK-REFERENCE GUIDE
RNI
There is no RN1 for fluoride. The recommended range is 1.5 to 4 mg a day
Sources
Tea is a rich source of fluoride. One cup of brewed black tea contains from I to 4 mg. Seafood is also a good source.
Possible Toxicity Problems
Abnormal hardening of the bones; joint pain and stiffness, weakness and occasionally nerve damage and paralysis. This occurs only after years of daily exposure to 20-80 mg of fluorine, far in excess of the average individual's intake.
Fluoride can be toxic. Consuming 2.5 to 5 g at one time can be fatal to adults and children. In children, amounts of more than 2.5 mg a day can lead to mottled tooth enamel.
