Enhancing swallowing initiation: The facilitatory role of crystalline oil and fat

• Crystalline oil and fat (COF) exhibiting potential for dysphagic patient treatment. • COF reduced the onset latency of cold sensation and prolonged its duration. • The number of swallows significantly increased after swallowing COF. • COF application induces a cold sensation and facilitates swallowing initiation. Medium-chain triglyceride (MCT) oil and fat are considered potential candidates to satisfy the nutritional demands of the increasing number of older patients requiring both dysphagia rehabilitation and nutritional therapy. Crystalline oil and fat (COF) is a unique material comprising MCT. In this study, we aimed to investigate the ways in which COF produces a cold sensation in the mouth, and assessed its facilitatory effect on swallowing initiation through two experiments. The first experiment, involving 27 participants, revealed that COF significantly reduced the onset latency of cold sensation and prolonged its duration compared to that of the control. The second experiment, involving 20 participants, revealed that the number of swallows significantly increased after swallowing COF. Our study confirms that the application of COF to the tongue induces a cold sensation and facilitates voluntary swallowing initiation. Therefore, COF holds great potential for aiding dysphagic patients.