Food Safety Update
May 29, 2007
Melamine has long been used in manufacturing plastics in the United States. Take a stroll through a store like Williams Sonoma, and you'll find your choice of melamine mixing bowls and melamine colanders, and even melamine toddler dishes. Lately though, melamine has been making headlines for a very different kind of use.
Earlier this year, when thousands of cats and dogs fell ill or died after eating particular brands of pet food, the FDA discovered melamine, and melamine-related substances like cyanuric acid, both in samples of pet food and in the wheat flour used as an ingredient in the pet food. Melamine was also found in the urine and kidneys of the deceased cats. After receiving over 10,000 complaints, and placing the pet food under a voluntary recall, links were made between the contaminated food and imported Chinese wheat gluten.
Since protein content can be related to nitrogen content, and melamine is high in nitrogen, adding melamine to a product can make it look like an increase in protein value. Melamine has no nutritional value, and therefore, its sole purpose in food is to artificially pump up protein levels.
There is no approved use for melamine in human or animal food in the United States, but this practice is not restricted in China. As it turns out, the Chinese wheat gluten manufacturer had added melamine to the mix to thicken the product, giving it that "gravy" texture that wet pet foods enjoy. They also added melamine to beef up labeled protein amounts.
Protein levels in food animal feeds are usually drawn from protein-rich soybean meal. While corn provides most of the energy in a feed, soybean meal is necessary to give the animals a balanced, protein-rich diet. Melamine enables the Chinese pet food ingredient exporter to replace richer sources of protein with the chemical while maintaining, at least on paper, the same, or even higher levels of protein.
"Bottom line?" says Paul Sundberg, Vice President of Science and Technology for the National Pork Board, "Melamine is cheaper than real protein."
When the FDA, already struggling from a 12 percent drop in field employees, failed to originally inspect the melamine-tainted wheat gluten, it found its way to domestic distributors. And to make matters worse, some of the contaminated pet food also made its way to swine, poultry and fish farms, where it was used for feed - a practice that is allowed according to federal regulations. The 50,000 swine, 80,000 poultry, and numerous fish in question were immediately placed under quarantine, and then eventually cleared after FDA testing confirmed those animals were safe for human consumption.
How safe are we? According to the FDA, if all the solid foods a person ate in the day contained melamine, potential exposure would be about 250 times lower than the dose considered safe. That means a person weighing 132 pounds would have to eat more than 800 pounds per day of pork or other food containing melamine to approach a level that would cause a health concern.
Now that we know that melamine can kill cats, but not humans, swine, fish, or poultry (a phenomenon that could be related to how melamine reacts with the high acidity of cat urine), the real struggle, says Sundberg, will be stopping this type of contamination from happening in the future. Especially since it shouldn't have happened in the first place.
"The FDA is responsible for inspecting imported foods to make sure they conform to U.S. standards, but they don't have enough people or enough money to inspect every load. And if changing domestic agriculture regulations keeps pushing our food supply off-shore, we will continue to be faced with unintended consequences," he says. "The likelihood of one of our domestic manufacturers putting melamine in wheat gluten isn't very high, but we will likely have less control over the quality of imported products."
Currently, FDA teams are investigating where the tainted material originated in China, concentrating on more than the two companies originally called into question for mislabeling melamine as wheat gluten and rice protein concentrate. In addition, an import alert remains for 46 shipments of vegetable protein brought into the U.S. from China. Domestic manufacturers are also undergoing surveillance. Sundberg is pleased with the FDA's swift reaction to containing the problem, and says there are lessons to be learned.
"For too long we have enjoyed an abundance of food at cheap prices in the U.S., and as a result, we seem to be taking our food security for granted," he says. "Pork producers, and other animals producers, need to keep good records, know where their feed is coming from and what the feed consists of. Food safety has become a national security issue."
Customers who may have purchased the tainted pet food should not feed the food to their pets and should be encouraged to return the items to the store. A list of recalled pet foods is available on the FDA's website:http://www.accessdata.fda.gov/scripts/petfoodrecall/