Decreased appetite (changes in the sense of taste and smell, appetite centre).
Saliva secretion decreases, mouth dryness is observed.
Swallowing changes that occur with aging are called 'Presbyphagia':
• Slower swallowing
• Age-related changes in tongue pressure
• Fatigue more quickly
• Disruption in compensation mechanisms
As a result of presbyphagia, dysphagia and aspiration are generally not seen in the normal aging process. This risk increases especially in the presence of underlying neurodegenerative disease, delirium, those using drugs with central nervous system effects, the presence of mechanical factors, sarcopenic and frail elderly.
Changes in the esophagus (presbiesophagus)
• Decrease in the number of myenteric neurons
• Decrease in contraction amplitude
• Insufficient relaxation of the lower esophageal sphincter
• Dilatation in the esophageal body
Gastroesophageal reflux increases with aging. The basic mechanism is the reduction of secondary peristalsis, which is an important clearance mechanism for escaping acid. In addition, lower esophageal sphincter pressure decreases (upper esophageal sphincter pressure decreases with aging)
Changes in the stomach
• Gastric mucosal defense mechanism is impaired (mucosal cytoprotective factors such as mucosal prostaglandin, mucus and bicarbonate decrease).
• The mucosal layer becomes thinner.
• Mucosal blood flow decreases.
• Pepsin and acid secretion are reduced.
• The prevalence of H. Pylori carriage increases.
• The passage of food slows down. This prolongs the contact time of NSAIDs and other harmful drugs.
Changes in the small intestine
• Absorption of macronutrients (fat, protein, carbohydrate) does not change with aging.
Therefore, malabsorption is always pathological in old age.
• With aging, absorption of vitamin D, folic acid, vitamin B12 and calcium may decrease; however, iron absorption is not impaired. For this reason, the underlying disease should be investigated in iron deficiency anemia seen in old age, and gastrointestinal system screening should be performed.
• Mucosal immunity and IgA production are reduced.
Changes in the colon
• Constipation is common.
• The frequency of diverticulosis has increased.
• Increased mucosal proliferation.
• C. difficile colonization increased.
• Rectal compliance decreases, fecal urgency may develop.
• Internal anal sphincter pressure and muscle thickness decrease. Connective tissue increases in the external sphincter.