Wide-ranging research on tooth decay has recently produced some surprising findings. One indicates that cheddar cheese may actually inhibit the tooth-decay process. It seems to have decay-slowing effect on human teeth if it is eaten immediately after sugar. Why cheese should have such an effect is un-known. It is speculated that the food might interfere with the acid that decays teeth or with bacteria that produce the acid. If so, it would be the first common food found to have this useful property, the other surprising research finding was that heavily sweetened cereals proved about equally potent in causing decay whetther they contained eight percent sugar or almost eight times that much.