Should You Be Worried About the Sodium Benzoate in Certain Foods and Drinks?

The preservative sodium benzoate is sometimes found in soft drinks.
Image Credit: Kwangmoozaa/iStock/GettyImages

Sodium benzoate is a type of salt preservative found in a variety of foods, beverages and condiments, according to the National Center for Biotechnology Information (NCBI). While it is generally recognized as safe in small doses, sodium benzoate may cause harmful health effects under certain conditions.

Read more: The Most Common Food Preservatives

What Is Sodium Benzoate Used For?

Sodium benzoate is a strong antimicrobial, according to the NCBI. It is commonly used to preserve acidic foods such as pickles, salad dressing, sodas and fruit juices, per the Center for Science in the Public Interest (CSPI).

Sodium benzoate's antimicrobial properties have also made it a common ingredient in many personal products like lotions, shampoos and makeup. It is also used in detergents and other cleaning products, as well as in certain medications, according to the NCBI.

Sodium benzoate does not occur naturally, according to the Electronic Code of Federal Regulations. It's formed when sodium hydroxide combines with benzoic acid, which is found in many plants and animal tissues, according to a May 2017 article in Critical Reviews in Food Science and Nutrition.

Is Sodium Benzoate Safe?

The Food and Drug Administration (FDA) lists sodium benzoate as GRAS, an acronym that stands for the phrase "generally recognized as safe." According to the FDA, the current safe level of sodium benzoate in food is 0.1 percent, which is a very small amount.

However, sodium benzoate may become a health concern when it is combined with ascorbic acid, aka vitamin C.

Read more: 20 Scary-Sounding Food Additives That Are Actually Harmless

When combined, sodium benzoate and ascorbic acid — both common ingredients in sodas — can form a chemical called benzene. Benzene has been linked to an increased risk of cancer, according to the FDA. The standard allowable amount of benzene in a beverage is 5 parts per billion (ppb).

The FDA cites a study conducted by the Center for Food Safety and Applied Nutrition (CFSAN) from 2005 to 2007 on the amount of benzene in sodas and other beverages. CFSAN found that "a small number of products sampled contained more than 5 ppb of benzene." However, when these products were reformulated as a result of this study, they contained less than 1.5 ppb of benzene. That's good news, but there hasn't been an update since 2007.

What's more, diet beverages are more prone to benzene formation, Bonnie Taub-Dix, RDN, creator of and author of Read It Before You Eat It: Taking You from Label to Table, tells "The conversion [of sodium benzoate to benzene] may also be affected by a drink's exposure to light and heat during storage," says Taub-Dix.

If you're concerned about benzene exposure, avoid buying soft drinks that list both sodium benzoate and ascorbic acid or its chemical cousin, erythorbic acid, according to the FDA.

Other Sodium Benzoate Considerations

As discussed, sodium benzoate is generally considered safe. However, some small studies have shown that sodium benzoate may lead to some unexpected health side effects.

Case in point: People who drank beverages with high levels of sodium benzoate (like soda) reported an increase in attention-deficit/hyperactivity disorder (ADHD) symptoms, according to an April 2014 study published in the Journal of Attention Disorders.

And taking in preservatives such as sodium benzoate could lead to low-grade inflammation in the body, a study published in March 2012 in the British Journal of Nutrition found. This kind of low-grade inflammation can be chronic in people with obesity. Note, however, that this study was only done in a laboratory setting rather than in human subjects. More research is needed to determine if sodium benzoate food additives exacerbate obesity-related health consequences.

Read more: Harmful Effects of Preservatives in Foods

references & resources