Fat increases vection-induced nausea independent of changes in gastric emptying.

Vection and fat delay gastric emptying and can induce nausea. Therefore, we studied the interaction between vection and fat on the production of nausea and the relationship between the severity of symptoms and changes in gastric emptying. Twelve healthy males consumed two liquid test meals, a zero-fat and a high-fat meal. Nausea was induced by seating the subjects inside a rotating vection drum. In protocol 1, drum rotation started immediately after ingestion of either meal; in protocol 2, when approximately 50% of each meal had emptied into the intestine. Gastric emptying was determined using gamma scintigraphy. Severity of symptoms was assessed throughout. Symptoms were similar for the high-fat and the zero-fat meal when vection was induced immediately after meal ingestion. Scores were only elevated by the high-fat meal when about half the meal had entered the intestine before vection was induced. No correlation was found between gastric emptying and the severity of symptoms. In conclusion, the interaction of vection and intraduodenal fat exacerbates nausea, but this effect is independent of a delay in gastric emptying.