As people age, several changes may affect the ability to swallow. Slightly less saliva is produced. As a result, food is softened (macerated) less well and is drier before it is swallowed. The muscles in the jaws and throat may weaken slightly, making chewing and swallowing less efficient. Also, older people are more likely to have conditions that make chewing and swallowing difficult. For example, they are more likely to have loose teeth or to wear dentures Dentures Teeth may be lost to a number of disorders including cavities, periodontal disease, or injury or may be removed when treatment fails. Missing teeth may cause cosmetic and speech problems and... read more .
With aging, the contractions that move food through the esophagus become weaker. This change is very slight and usually has little effect on moving food to the stomach. But if older people try to eat while lying down or lie down just after eating, food may not easily move to the stomach. If reflux develops, the aging esophagus may be slower to move refluxed stomach acid back into the stomach. Some older people have a hiatus hernia Hiatus Hernia Hiatus hernia is an abnormal bulging of a portion of the stomach through the diaphragm. The cause of this disorder usually is not known, but age, obesity, and smoking are common factors. Some... read more , which may contribute to reflux.