Saliva Secretion and Swallowing—The Impact of Different Types of Food and Drink on Subsequent Intake

The oral processing of food is important for eating and digestion in order to gain energy and nutrients. Due to disease, injury, or aging, individuals may experience difficulties in this process. These difficulties often lead to dysphagia, which is associated with malnutrition. Thus, it is of importance to find solutions and strategies to enable food intake. It is well known that sour and/or carbonated foods and drinks increase saliva secretion and trigger the swallowing reflex. However, knowledge regarding how subsequent food intake is impacted is lacking. The aim of this study was to clarify whether sour and/or carbonated foods and drinks had subsequent impacts on swallowing function. Twelve healthy participants evaluated eleven foods and drinks in terms of their ability to increase saliva production and ease the swallowing of subsequent food. Results showed that sourness and carbonation had positive impacts on saliva secretion and swallowing. No correlation was found between the pH/sourness of the foods and the ease of swallowing them. It was concluded that the ingestion of cherry tomatoes, natural yoghurt, and, in particular, citrus juice made swallowing of a neutral cracker easier. These results may be used to increase food intake among dysphagia patients.