Animals lick their wounds. Why? No one is sure.

People have been told for years not to lick wounds because the mouth is filled with bacteria, so the experts told us that licking a wound would be the worst possible thing we could do.

Now researchers have discovered a compound in saliva that speeds up healing. The compound is called histatin, and it was formerly thought only to kill fungi.

Rodent saliva also contains various growth factors that are thought to accelerate healing, but the concentrations of the growth factors in human saliva is low.

The researchers said histatin may explain why wounds in the mouth heal faster than wounds elsewhere in the body. A year or so ago I tripped coming out of my barn office in the dark and fell on my face, and a tooth went right through my lip. Or course it did swell up, and after a couple of days I did get an antibiotic shot and a tetanus shot, but I was amazed at how quickly it healed despite being exposed to all the germs that are on the food we eat.

This change in viewpoint from "never do this" to "maybe it helps" reminds me of a similar situation with treating burns. One's instinctive reaction after being burned is to cool down the burn with running cold water. But for years, people were told not to use water on a burn, that what you should do with a minor burn was to cover it with a bandage or use burn cream or butter or grease.

Then a physician, Dr. Alexander G. Shulman, burned his hand with boiling grease and instinctively plunged it into cold water. He discovered that actually, cooling minor burns in cool water was much better, relieved the pain, and speeded up healing. Now they tell us never to use butter or grease on a burn. It turned out that our instinctive reaction was correct after all.

Animals don't read first aid manuals, but they have a lot of instinctive reactions to health problems. They lick their wounds. They eat certain herbs when they have digestive problems [one researcher discovered that when the worm burden in a group of chimpanzees got high, they ate a bitter plant they'd never eat otherwise, and it turned out to be the same plant that the local people ate for the same problem]. Animals often carry their infants around on their backs without worrying that they'll spoil them.

So what does all this mean for us? Should we just go with our instincts when it comes to health care and ignore all the advice we get from our doctors and other health care people?

Of course not. Modern medicine saves a lot of lives. Most of the advice given by medical people is good, and we should listen.  But we should also keep an open mind and not assume that just because some approach to treating some medical condition is the official way today it's really the best way.

One example of this is the dietary advice being given to people with diabetes. Years ago, people with diabetes were told to avoid carbohydrates. A "diabetic diet" in a home medical book from about 1910 is even stricter than Atkins. Then with the discovery of insulin and the finding that saturated fat seemed to increase heart attack rates, people with diabetes were told to avoid all fats [they figured people weren't smart enough to learn the difference between saturated fats and other fats], eat more carbs, and cover the carbs with insulin or oral drugs if necessary.