The number of additives in packaged foods is on the rise, and concerns about the safety of some have made headlines. Here’s what to know. By Sarah Garone Medically Reviewed by Lynn Grieger, RDN, CDCES on March 28, 2024.  

Chemicals including calcium propionate, sodium benzoate, potassium sorbate, BHA, and BHT are common preservatives in salad dressing, cheese, and other foods. 

It’s become increasingly apparent that a diet that focuses on whole foods and limits ultra-processed ones is the best from a health standpoint. Research published in February 2024 in The BMJ found that the more ultra-processed foods in a diet, the greater the risk of cardiometabolic and mental health disorders, as well as death from any cause.

In spite of that, the number of additives in the U.S. food supply is growing. More than half of all groceries purchased by Americans contain some kind of chemical coloring or flavoring agents, preservatives, and sweeteners, a 10 percent increase since 2001, according to research published in the Journal of the Academy of Nutrition and Dietetics.

Evidence that such additives may be a cause for concern continues to mount. A recent study found that one common preservative, found in cheese, dipping sauces, and beer, among other foods, may negatively affect gut health.

 And earlier this year, a class action lawsuit was filed over the use of the term “no added preservatives” on food labels, calling into question how, exactly, we define preservatives and other food additives.

While some food additives may be questionable, others are necessary for preserving freshness, quality, or other reasons. Often, though, food labels are full of ingredients that are unfamiliar to anyone but a chemist or food scientist. So how do you know what’s in the food you’re eating, and how safe it is? We asked some experts to dig into the topic.

What Are Preservatives and Why Are They Used?

There are plenty of social media rants about “chemicals in our food,” but all foods contain chemicals. Sometimes those chemicals are there naturally, and sometimes they are added by food scientists to enhance the food’s life (preservatives), its texture (stabilizers), or some other attribute like flavor or color. Because the names of these chemicals may not be instantly recognizable to the average consumer on food labels, they’re often villainized, but many do serve important purposes.

“Food preservation is defined as any act or addition that inhibits undesired bacterial growth or chemical changes in a food,” says Alyssa Pike, RD, senior manager of Nutrition Communications at the International Food Information Council in Washington, DC. In other words, preservatives keep food safe for consumption. Stabilizers, on the other hand, create stable emulsions or gels, adding thickness to foods for greater palatability and shelf stability.

Many forms of food preservation (such as drying, chilling, and curing) have existed for thousands of years. Nowadays, modern science has taken the process even further. “In addition to older forms of preservation that use salt and acid, other, more modern preservatives can offer benefits like inhibiting oil from going rancid or helping a food product retain its original color,” Pike says. Besides increasing food safety, this ultimately prevents food waste, according to research published in 2021 in Environmental Chemistry Letters.

Natural Versus Artificial Preservatives

Food preservatives are classified as either natural or artificial. Natural preservatives derive from a natural source such as plants. Sugar, salt, and citric acid made from citrus fruits are considered natural preservatives. Artificial preservatives, on the other hand, are man-made, typically synthesized in a lab. According to the Encyclopedia of Food Safety, some examples of artificial preservatives include:

·        Sodium benzoate, found in soft drinks, salad dressings, and canned tuna

·        Calcium propionate, found in baked goods, processed meats, and dairy products

·        Potassium sorbate, found in cheese, wine, and dried meats

·        BHA and BHT, found in margarine and potato chips

·        TBHQ, found in pasta, cereals, and nuts

The word “natural” has more positive connotations — so it’s only, well, natural to incline toward purchasing foods that contain these preservatives, rather than artificial ones. But Donald Schaffner, PhD, a food scientist and distinguished professor at Rutgers University, says this isn’t necessarily something to worry about. “While the distinction of natural and artificial is something that the average consumer might think about, from a scientific perspective, a compound like citric acid is identical whether it is found naturally in fruits or whether it is synthesized in a factory by microorganisms,” he says. “The body doesn't care. It only knows that it is citric acid.”

Plus, though preservatives like salt and sugar derive from sources you’ll find in nature, that doesn’t mean they’re without health risks. Too much sugar in the diet has been linked with increased risk of obesity.

And people with heart health concerns would do well to limit their salt intake, since too much sodium can raise the risk for heart disease and stroke.

Potential Health Impacts of Preservatives: Good and Bad

Overall, the news about food preservatives is good. “The FDA confirms the safe use of all the preservatives in our food and beverage supply, and each preservative, whether artificially created or naturally sourced, must pass rigorous evaluation for safe use, including a dossier containing a full scientific evaluation,” Pike explains. Once a preservative passes this process, it’s designated as “Generally Recognized as Safe,” or GRAS. “This means the ingredient is certified and managed as safe to eat by the FDA,” she says. From there, a preservative can legally make its way into the food supply.

Still, it’s understandable if you have lingering concerns about the safety of certain ingredients — especially when scary reports about them crop up in the news, like nisin, which was the preservative linked with harming gut health. TBHQ has also come under fire for potentially harming the immune system.

 And last year, California passed a bill banning the use of four food additives, including the preservative propyl paraben, which is sometimes used in baked goods to reduce microbial growth and increase shelf life.

Does this mean you should avoid those ingredients? In the case of the California ban, the research linking the additives to negative health outcomes was conducted on animals, not people, so it is not conclusive from a scientific standpoint. And Pike points out that in addition to certifying additives as GRAS, the FDA keeps tight control over how much of certain additives can be included in foods. Case in point: “TBHQ levels cannot account for more than 0.02 percent of the fat and oil in food,” she says.

A health consumer watchdog group, the Center for Science in the Public Interest (CSPI) based in Washington, DC, maintains a large database that ranks the safety of food additives.

 The database highlights concerns from consumers and clinicians that preservatives and stabilizers may not be as safe for eating as the U.S. Food and Drug Administration (FDA) would have us believe. But, according to Schaffner, “One critical aspect that is missing is a lack of citations to the scientific literature.” This lack of citation and insufficient detail make firm health claims about individual preservatives hard to verify, he says.

Should You be Concerned About Food Preservatives and Stabilizers?

Any food preservative or stabilizer on the market today has been subjected to federal safety guardrails. “The FDA and USDA Food Safety and Inspection Service would not allow anything to be used in foods which they felt had significant public health consequences,” says Schaffner. According to Food and Nutrition, the official magazine of the Academy of Nutrition and Dietetics, stabilizers must undergo rigorous testing and safety analysis prior to approval in the U.S. food system.

 Of course, if you know you’re sensitive or allergic to any ingredient in foods, it’s best to avoid it. But in general, most of us don’t need to fear foods with preservatives or stabilizers, whether natural or artificial.

The bigger take-home, says Pike, is to focus your eating around whole foods that inherently contain fewer preservatives. “If you’re worried, remember that eating a balanced diet that contains fruits, vegetables, lean protein, healthy fats, and whole grains is the main priority.”