Our Saliva's Vital Functions

As we had earlier discussed in the two-part article, Hormone Imbalance: Disease Indicator (posted last August 15 and 22, 2011), our saliva is not only used for testing hormone levels but also performs other functions necessary for cellular energy and metabolism.

The secretion of saliva is one such function, often ignored, that can go wrong for most people as age advances. Looking like tiny clusters of grapes, there are six salivary glands, three on each side of the mouth. The parotid, below the ear, is the largest; the sublingual glands are under the tip of the tongue; the remaining two submaxillary glands are under the lower jaw. Together, the glands secrete more than two and a half pints of saliva a day (not much, considering the cow produces about 12 gallons daily).

Because we seldom miss the water until the well runs dry--or we feel thirsty--we take saliva for granted. But saliva does more than wet our tongue: it is important in the digestion of food. While our teeth grind food into the pulp called bolus, digestive juices in the saliva begin the breakdown of carbohydrates.

The reason we are advised to chew our food well is that digestion starts in the mouth. Anything put into the mouth causes a flow of saliva. It not only liquifies and lubricates the food to be swallowed, it activates the taste bud glands which stimulate the release of digestive juices in the stomach. And to keep our mouth healthy, our saliva excretes germ-killing substances that protect our mouth from disease.

The smell, and even sight, of savory food will make the mouth water, while fear, nervousness and depression can cause dry mouth, all demonstrating that our salivary glands are influenced by the nervous system.

Dry mouth is often a symptom of disease, and possibly the most serious is diabetes. The research group at the University of Alabama Department of Oral Medicine, headed by E. Cheraskin, M.D., D.M.D., found that a dry mouth is not only a symptom of diabetes or a similar condition of hyperglycemia but actually reflects any disorder of the carbohydrate metabolism that will cause the blood to contain too much or too little sugar.

Physiological disorders can influence the salivary flow. Mumps and other virus infections affect the parotid gland, and such infections are fairly common in people over sixty.

Salivary ducts (tubes) can be blocked by stones (calculi). When this occurs in the submaxillary duct, it is sometimes possible to feel a tender lump in the lower mouth under the tongue. Abscess is a frequent result and surgery is usually required to bring relief.

Hypersecretion can result in up to 10 quarts of saliva in a day. The cause can be ill-fitting dentures, drugs, various poisons, and a long list of organic and emotional disorders. If your flow of saliva has changed and you think it might be more or less normal, see your doctor.