Fishy lobster? Some food additives that help to keep lobster and other shellfish looking fresh might be changing human hormones.
FLICKR/IAW KEVEN

A discovery that two commonly used food additives are estrogenic has led scientists to suspect that many ingredients added to the food supply may be capable of altering hormones.

More than 3,000 preservatives, flavorings, colors and other ingredients are added to food in the United States, and none of them are required to undergo testing for estrogenic activity, according to the Food and Drug Administration.

“We need to be mindful of these food additives because they could be adding to the total effect of other estrogen mimicking compounds we're coming into contact with,” said Clair Hicks, a professor of food science at the University of Kentucky and spokesperson for the Institute of Food Technologists, a nonprofit scientific group.

“The benefits of using these additives in food need to be weighed against the risks they present,” Hicks said.

In a study published in December, Italian researchers screened 1,500 food additives using computer-modeling software, a much faster and cheaper approach than testing lab rats.

The researchers first used modeling to identify 13 molecules that could hypothetically bind with an estrogen receptor, a group of molecules activated by the hormone. Like a clenched fist that fits into the palm of a hand, potentially estrogenic molecules will “fit” inside the receptor, indicating they could interact and alter hormones.

Then, the researchers exposed cells to the 13 food additives, which confirmed that two have estrogen-mimicking properties. Known as “xenoestrogens,” these substances have been linked to reproductive problems in animals and perhaps humans.

The first food additive, propyl gallate, is a preservative used to prevent fats and oils from spoiling that can be found in a range of foods including baked goods, shortening, dried meats, candy, fresh pork sausage, mayonnaise and dried milk.

The second additive, 4-hexyl resorcinol, is used to prevent shrimp, lobsters, and other shellfish from discoloring.

“Some caution should be issued for the use of these two additives,” said Pietro Cozzini, one of the researchers who conducted the study and a chemistry professor at the University of Parma in Italy.

He added that further tests on rats are necessary to determine whether these additives could harm humans.

Paul Foster, whose research focuses on the potential human health effects of endocrine disruptors, agreed. He said there is a big difference between adding estrogenic molecules to cells in a culture dish and actually seeing what happens when that dose is administered to an animal.