Accumulation in the blood of a deuterium tracer added to hot and cold beverages

Deterium (²H) accumulation in the circulation was determined in 10 subjects after they ingested 7 ml · kg⁻¹ of a dilute glucose-electrolyte solution that contained 10 g of ²H₂O and was hot (50°C) on one occasion and cold (4°C) on another. In addition, 7 subjects repeated their first trial on a third occasion. Subjects fasted overnight and remained seated at rest during the experiment Blood ²H concentration was significantly greater at 5 min after ingestion of the hot as compared with the cold treatment and at 60 min for the cold as compared with the hot treatment The rate of blood ²H accumulation was not different when the same solution was ingested on different days. The results indicate that the rate of ²H accumulation is: 1) similar for hot and cold solutions and 2) reproducible when the same solution is ingested on different days. This implies that the rate at which dilute glucose-electrolyte solutions are made available to the body is not much influenced by the temperature at which they are ingested.