One memory I have from childhood is of Mrs Pearl – a formidable playground patroller and dinner lady at the junior school I attended in suburban Essex. Mrs Pearl had a very defined view of how children should behave, right down to their eating habits. One of Mrs Pearl’s preoccupations was to remind us of the importance of proper chewing, and anyone caught speed-eating would undoubtedly incur her wrath. Latterly, my interest in nutrition has led me to give the value of mastication proper consideration. While the act of chewing may seem relatively superfluous, it actually plays a critical role in digestion. In so doing, chewing helps to ensure we extract maximum nutritional value from the food we eat. The reality is that Mrs Pearl’s views on the importance of chewing turn out to have real bite after all.
When the pace of life is fast, and when we’re trying to cram as much as possible into the day, eating can be something we tend to do on the hoof. Many of us can find ourselves stuffing a sandwich or cereal bar into our mouths, satisfied that we’ve at least managed to get something down us. However, the gut is essentially a long tube that runs through the middle of the body. This means that food in the gut is not really in the body at all. It’s only once food makes its way through the gut wall into the body proper that it can liberate its nutritional goodies into the system.
The majority of food we eat is simply too big to breech the digestive tract wall. Before we can absorb our food, it generally needs to be broken down (digested) first. Chewing is important because it plays a starring role in the digestive process. During chewing, glands found in the cheeks, inside the lower jaw and under the tongue secrete saliva into the mouth. Saliva helps moisten and shape the food for easy swallowing. Saliva also contains an enzyme known as amylase that starts the digestion of starchy foods such as bread, potatoes, pasta and rice. During chewing, the tongue also secretes an enzyme called lipase that participates in the digestion of fat.
Once food is swallowed, food is further digested through the secretion of a variety of compounds including acid in the stomach, bile from the gallbladder and enzymes in the small intestine. Chewing and the sensation of food in the mouth is believed to help stimulate the secretion of this food-dissolving substances. Eating bitter foods such as salad leaves helps stimulate digestive secretions, making them an ideal base for a starter. Chicory is especially good in this respect, and is renowned in herbal medicine for its ability to boost digestion.
However, for acid, enzymes and bile to do their work, they need to able to penetrate the food we eat. One final function of chewing is to grind food up, which gives the digestive secretions a fighting chance of completing the digestive process. What is more, the smaller the food particles we swallow, the quicker and more efficient digestion tends to be. One very simple and very effective way of boosting the nutritional value of our diet is to comply with Mrs Pearl’s demands, and chew each mouthful of food properly before swallowing.