What is TBHQ?

If you're someone who likes to know what they're eating and frequently reads food labels, you may have come across the term tertiary butylhydroquinone or TBHQ. TBHQ is a preservative used to prevent fats from oxidizing because oxidation causes discoloration, odors, loss of flavor, and a loss of nutrients.

Overall, TBHQ is added to processed foods to help increase their shelf life. Although TBHQ acts as an antioxidant, it is not like healthy antioxidants found in fruits and vegetables.

This substance has a questionable reputation that could come with adverse effects. Here's what you need to know about TBHQ including the risks associated with its consumption.

History of TBHQ

The Food and Drug Administration (FDA) approved the use of TBHQ in 1972, labeling it as GRAS, or “Generally Recognized as Safe." But is this preservative truly safe?

The answer is complicated. Research has had mixed findings. Plus, the FDA limits how much can be added so that people don’t become ill. Whether or not small doses are genuinely safe, especially long-term has yet to be determined, though.

“Since the FDA cleared its usage back in 1972, the use of packaged, processed, and frozen meals have increased in popularity, thus increasing the overall consumption of TBHQ," explains Hailey James, RDN-E, a registered dietitian with Wellory Nutrition Coach.

Overall, it is generally beneficial for overall health to stay away from these preserved, packaged, and high concentrations of fats and oils and focus on filling plates with fresh, whole-food ingredients, James says. It's also important to understand the impacts foods with TBHQ could provide.

What is TBHQ?

TBHQ, also known as tertiary butylhydroquinone, is a preservative. This means it is used to help food last longer when stored. More specifically, it is a synthetic antioxidant that is used to preserve fatty or oily foods.

TBHQ is sprayed on foods or their packaging to prevent odors or discoloration during storage. It can also be found in cosmetics and varnishes, among other things. The big appeal to preservatives like TBHQ is that they increase the shelf life of foods, keeping food costs and food waste down. 

The antioxidant properties of TBHQ eliminate the oxygen content of foods, which keeps them from going stale or becoming unappetizing. The FDA and the European Food Safety Authority (EFSA) generally recognize TBHQ as safe in small doses. Additionally, both the FDA and EFSA have placed a limit on the percentage of TBHQ permitted in foods to no more than 0.02% of the item's total fat and oil content.

TBHQ is found in various processed foods, such as instant noodles, snack crackers, and frozen foods. It is also found in a lot of fast foods, such as McDonald’s chicken nuggets. You can pretty much find it in any item that you would store on the shelf or in the freezer.

Dietary Risks of TBHQ

Because the FDA regulates TBHQ, it would be near impossible to consume enough to become ill. That being said, it may be best to avoid consumption of it if you can. Even though it is considered safe in small amounts, that does not mean it is healthy for you.

For example, a study by the Centers for Science in the Public Interest (CSPI) has shown that TBHQ can increase the chances of a tumor-forming in rats who consume it. Despite this study, the overall debate on whether or not TBHQ can cause tumors is still inconclusive.

Meanwhile, the Feingold Diet, intended for lessening the symptoms of attention-deficit hyperactivity disorder (ADHD), excludes the consumption of TBHQ and similar preservatives. And, a study by Cheryl E. Rockwell from the University of Michigan indicated TBHQ might play a role in developing food allergies.

These findings seem to be all over the place, implying a wide range of both physical and neurological effects. But what could they have in common? One answer is the immune system.

In fact, according to the International Journal of Environmental Research and Public Health, even small doses of TBHQ can be detrimental to your immune system and appears to have 12 different interactions with the immune system—even going as far as to make vaccinations less effective. In fact, a study in mice found that the cells responsible for fighting viruses were much slower to respond and eradicate the virus when the mice were given TBHQ in their diet.

The journal even went as far as criticizing the joint FAO-WHO expert committee report on food additives, the U.S. National Toxicology Program (NTP), and the European Food Safety Authority for not investigating further on the harm potential of TBHQ to the immune system. Still, further human investigation is needed to verify this harm.

How to Avoid TBHQ

If you are trying to limit your consumption of TBHQ, you should begin to read the labels of your shelved and frozen foods. TBHQ can appear on the label in a few different ways, so it's important to read carefully if you want to limit your exposure to TBHQ.

You also may want to consider limiting how much fast food you and your family eat as TBHQ is present in many of these foods. The best way to ensure you eat as little TBHQ as possible is to opt for fresh ingredients, such as fresh fruits and vegetables, fresh meats, and fresh fish. 

A Word From Verywell

Although the research is mixed on the safety of TBHQ long-term, most people are concerned that consuming it on a consistent basis poses some health risks. For this reason, many people have started trying to avoid or limit their intake of preservatives like this one.

If you want to limit your consumption of TBHQ, it's important to read all food labels closely. Of course, if you find reading labels confusing and tiresome, you can always opt for whole foods that are fresh and preservative-free. You also can talk to a registered dietitian in order to get more information and determine what is right for you.