Project leader Distinguished Professor Kourosh Kalantar-zadeh, from RMIT University's School of Engineering in Melbourne, Australia, said the results of the study, which used pigs, seemed to show that cinnamon maintained the integrity of the stomach wall.

"When pigs feed at room temperature, carbon dioxide (CO₂) gas increases in their stomach.

"Cinnamon in their food reduces this gas by decreasing the secretion of gastric acid and pepsin from the stomach walls, which in turn cools the pigs' stomachs during digestion.

"When the pigs are hot, they hyperventilate, which reduces CO₂ production. With cinnamon treatment, CO₂ decreases even further.

"This not only cools the pigs but leads to a significant improvement in their overall health."

Fellow researcher Dr Jian Zhen Ou said: "Altogether cinnamon cooled the stomach by up to 2°C.

"No wonder cinnamon is so popular in warm regions as taking it makes people feel better and gives them a feeling of cooling down."