chew

Chew is the act of biting and grinding food or other substances with the teeth or jaws. As a noun, a chew can refer to a portion of food that has been chewed or to a chewable product, such as chewing gum. The verb and noun share a common Indo-European origin, from roots meaning to bite or bite off.

In humans, mastication is performed by the teeth and the muscles of mastication—the masseter, temporalis, and the pterygoid muscles—under neural control from the trigeminal nerve. The process is both mechanical and chemical: teeth break food into smaller pieces while saliva lubricates, buffers, and begins digestion with enzymes such as salivary amylase. Saliva also helps form a cohesive bolus and protects the mouth. Chewing stimulates swallowing and prepares food for digestion in the stomach.

Chewing gum is a modern nonnutive chew designed for prolonged mastication, often sugar-free and flavored. Edible chews include vitamins, minerals, or candy designed to be chewed rather than swallowed. The practice has historical roots in ancient cultures; for example, the Maya used natural chicle as a base for chewing gum before synthetic alternatives became common.

In animals, cud-chewing describes the regurgitation and re-chewing of food in ruminants such as cattle and sheep, enabling microbial breakdown of cellulose in a multi-stomached digestive system. Many other animals chew primarily to process food during feeding.

Health considerations include the role of chewing in saliva production, which aids digestion and oral cleansing. Excessive grinding or bruxism can wear teeth and cause jaw pain. Sugar-containing chews can increase the risk of dental caries, while sugar-free gums containing xylitol may reduce caries risk. Chewing also poses choking hazards, especially for small children or poorly chewed large items.