Gastrointestinal Tract - Changes Associated with ageing?
Many path physiological factors limit the adequacy of the dietary intake of elderly. Loss of natural dentition may occur due to tooth decay and gum disease. Loose painful teeth and ill-fitting dentures can result in mastication difficulty. Swallowing of food without proper mechanical chewing further leads to digestive problems. Certain other age-related changes include a decline in the sense of taste and smell which result in the lessening of appetite and reduction in the quantity of food consumed. The number of taste buds decreases with ageing which reduce sensitivity to taste and food may seem to be 'less appetizing' and have lost its 'natural taste'. Decreased secretion of saliva leads to dryness of mouth, thus making swallowing difficult. In the food passages, there is an increase in non- propulsive contraction which may lead to impaired absorption of nutrients. The incidence of gastric movement and gastric emptying diminishes progressively with age. Further, there is a decrease in the amount of acid and other digestive juices secreted by the digestive tract. Pancreatic enzyme section is not very much altered in old age. The food stays in stomach for longer period of time which gives a feeling of fullness and heaviness. Fat absorption is slightly impaired. In the small intestine, the blood flow is reduced by 40% and absorptive capacity by 30%. Carbohydrates and fat absorption decreases to a lesser extent with age and the protein absorption remains intact. The volume, acidity and pepsin content of the gastric juice is sometimes reduced. In turn, there is an interference with the absorption of calcium, iron, zinc and vitamin B12.
The motility of large intestine and elasticity of the rectal wall decreases with advancing age due to decrease in muscle activity and constipation is likely to be a frequent complaint.Fats may be poorly tolerated because they further retard gastric emptying. This happens as the pancreatic production of lipase (fat-digesting enzyme) is inadequate for satisfactory hydrolysis and there may be a reduced production of bile due to chronic biliary impairment.