Influence of age on mastication : effects on eating behaviour.
Nutrition Research Reviews 2004, 17, 43-54 Mioche et al
During the process of eating food is first chewed. This is process wherein the food is broken down by rhythmic movement of the jaws up and down. The teeth break up the food and saliva is added which facilitates the swallowing of the cohesive wet mass the bolus. This is a complex process which involves the teeth, jaw muscles, temporo-mandibular joints, tongue, lips, cheeks, palate and salivary glands. There are considerable differences in the time that various people and peoples take over chewing. There are cultural differences between peoples, such as the rapid eating of meals which some Chinese enjoy and the prolonged time that the French take as they enjoy their food. The Victorian British Prime Minister Gladstone was said to chew each mouthful 30 times. The Buddhists ask us to eat slowly and mindfully. Fast food, fast eating .
The amount of time spent chewing will determine the bolus properties, but the end result tend to be the same in most people.
Chewing is part of the pleasure of eating and enjoying the taste and texture of the food. The condition of the teeth can effect the chewing process.
What are the effects of ageing on chewing and Mastication variables?
Teeth. Loss of teeth may reduce mastication efficiency.
Muscle activity. With senescence the muscles decline in strength and speed and hence the bite.
The tongue. The tongue musculature is peculiar to the tongue to allow the tongue to move in all the directions it is capable of in eating, talking etc.
Oral sensitivity. The sensitivity of the mouth declines with age and presumably the enjoyment of food with sensory stimuli.
Salivary secretion. Normally 1-1.5 litres of saliva are produced each day. Dry mouths are complained in a quarter of institutionalised elderly. Medication can however reduce salivary flow. Good salivary flow is important for swallowing and also enjoying food.
Swallowing. Impaired swallowing is common in the elderly.
Chewing pattern and texture. Texture is the sensory manifestation of food structure, and will influence chewing. The chewing cycle pattern may be affected by age.
In general healthy ageing has only minimal effects on oral physiology. Disease process may affect chewing and swallowing in many ways.
- Martin Eastwood