Taiwanese researchers found that hot temperatures increase the amount of melamine we are exposed to - and this can raise the risk of kidney stones.
They studied two groups of people who ate piping hot noodle soup. One group ate from melamine bowls, the other from ceramic bowls.
Urine samples were collected before the meal, and every two hours for 12 hours following the meal.
Three weeks later, the volunteers consumed the same kind of soup but the type of bowl they used was reversed. Urine samples were collected again, the 'Daily Mail' reported.
Total melamine levels in urine for 12 hours after eating the soup was 8.35 microgrammes when the participants ate out of the melamine bowls versus about 1.3 microgrammes when they ate out of ceramic bowls.
"Melamine tableware may release large amounts of melamine when used to serve high-temperature foods," lead researcher by Chia-Fang Wu, of Kaohsiung Medical University in Taiwan, said.
He noted that both higher temperatures (from hot soups, for example) or more acidic foods can encourage melamine to contaminate food, especially in older or low-quality kitchenware.
But he added that the amount of melamine released into food and beverages from melamine tableware varies by brand, so the results of this study of one brand may not be generalised to other brands.
However the study suggested it is advisable to serve hot food on ceramic crockery, to be on the safe side.
The findings back up previous research that found a link between melamine and kidney stones in both children and adults.
In 2008, melamine-tainted baby formula (causing an especially high dose) was linked to six deaths and 50,000 hospitalisations related to kidney stones and kidney disease in China.
The study was published in the journal JAMA Internal Medicine.
