Preservative used in hundreds of popular foods may harm the immune system

Washington, (Environmental Working Group) - A food preservative used to prolong the shelf life of PopTarts, Rice Krispies Treats, Cheez-Its and almost 1,250 other popular processed foods may harm the immune system, according to a new peer-reviewed study by Environmental Working Group (EWG).

As a result of the study, EWG has called on the United States Food and Drug Administration (FDA) to close the regulatory loophole that allows potentially unsafe food additives to remain on the market. The FDA should also promptly review additives like TBHQ to reflect new science.

For the study, published last week in the International Journal of Environmental Research and Public Health, EWG researchers used data from the Environmental Protection Agency’s Toxicity Forecaster, or ToxCast, to assess the health hazards of the most common chemicals added to food, as well as the “forever chemicals” known as PFAS, which can migrate to food from packaging.

EWG’s analysis of ToxCast data showed that the preservative tert-butylhydroquinone, or TBHQ, has been found to harm the immune system in both animal tests and in non-animal tests known as high-throughput in vitro toxicology testing. This finding is of particular concern during the coronavirus pandemic.

“The pandemic has focused public and scientific attention on environmental factors that can impact the immune system,” said Olga Naidenko, Ph.D., EWG vice president for science investigations and lead author of the new study. “Before the pandemic, chemicals that may harm the immune system’s defense against infection or cancer did not receive sufficient attention from public health agencies. To protect public health, this must change.”

TBHQ is a preservative that is pervasive in processed foods. It has been used in foods for many decades and serves no function besides increasing a product’s shelf life. Using new non-animal test results from ToxCast, EWG found that TBHQ affected immune cell proteins at doses similar to those that cause harm in traditional studies. Earlier studies have found that TBHQ might influence how well flu vaccines work and may be linked to a rise in food allergies.

Using ToxCast, EWG analyzed all publicly available studies that show how PFAS migrate to food from packaging materials or processing equipment. This is the first known compilation of available research on PFAS migration from packaging to food. Human epidemiological studies show that PFAS suppresses immune function and decreases vaccine efficacy. Recently published research has also found a link between high levels of PFAS in the blood and the severity of Covid-19.

Surprisingly, for most PFAS, the ToxCast results did not match previous animal and human test data. This illustrates the limitations of this new chemical testing method. More research is needed to understand how PFAS harm the immune system.

Processed foods can be made without these potentially harmful ingredients, so shoppers should read labels carefully. TBHQ is often, though not always, listed on the ingredient label. It will be listed if it has been added to the product during manufacturing. But it can also be used in food packaging, particularly plastic packaging, in which case it may migrate to food.