10/08/2025
Processed foods can be a double-edge sword. On one hand, they’re easy, convenient time savers. But they are often made with questionable ingredients, from high fructose corn syrup, excessive salt and added sugars.
But there are many other ingredients that can be detrimental to your health that get less attention, in particular, preservatives. There’s a wide range of preservatives, some deemed as safe, while others should be limited or even avoided. Here are five preservatives that some experts think may have a tie to cancer.
Sodium benzoate – combines sodium hydroxide with benzoic acid – an acid found naturally in blueberries, cranberries, cloves and cinnamon. It’s a byproduct of fermentation. Sodium benzoate is commonly added to acidic foods like fruit jams, pickles and pickled foods, olives, beer, fruit yogurts, some canned vegetables, carbohydrate drinks, bottled lemon and lime juice, sauces, dressings, mayonnaise, margarines and tomato paste. You’ll also find it in some brands of shampoos, mouthwashes, cough syrups and soaps. The Food and Drug Administration (FDA) recognizes sodium benzoate as safe; however, some studies suggest differently. For instance, sodium benzoate was linked to a wide range of health issues, according to a study published in Nutrients, because it can:
Increase oxidative stress
Decrease s***m count and testicular function
Damage kidney and liver in rats and mice
Trigger attention-deficit hyperactivity disorder in children and college students
Converts to benzene -- a chemical considered a carcinogenic by the International Agency for Research on Cancer – when combined with preservatives ascorbic acid, citric acid and vitamin C. Foods that often use this blend of preservatives include breads, cured meats, jams/jellies and carbonated beverages, particularly the diet and sugar-free varieties.
Tertiary butylhydroquinone (TBHQ) - is an antioxidant that extends the shelf life of food by preventing fat from breaking down. Once fat begins breaking down in food, it can cause the food to lose its flavor, color and nutritional value, to become rancid and to spoil. You’ll find TBHQ on the ingredient list of oils, soft drinks, crackers, chips, cereals, donuts, some breads, many microwavable foods, pre-made frozen meals, some dairy products, non-organic frozen fish items, some brand of soy milk. It’s also used in skincare products and varnishes. The FDA approved for its use as a food antioxidant in 1972; however, restricted its amount to no more than 0.2 percent of the oils in a food, as there’s not enough evidence to suggest it’s safe beyond those limits. In higher doses TBHQ has been linked to cancer, according to a study published in the journal Toxicology Reports. It’s also been found to enlarge the liver and cause convulsions in humans and paralysis in laboratory animals.
Butylated hydroxyanisole (BHA) – is often used in conjunction with butylated hydroxytoluene (BHT). They’re synthetic antioxidants that delay the breakdown of fats in ultra-processed foods like meats, cereals, baked goods, sweets, beer, potato chips, certain kinds of nuts and most snack products, as well as cosmetic products such as lipsticks and moisturizers. BHA’s purpose is preventing rancidity and spoilage, while BHT helps products maintain their color, taste and scent. Both are generally recognized as safe by the FDA, but other agencies categorize BHA as a:
Possible carcinogen to humans - International Agency for Research on Cancer
Potential endocrine disruptor - European Commission
Substance to be avoid/potential carcinogen – Center for Science in the Public Interest
Additionally, TBHQ (see above) is also formed with the body metabolizes BHA.
At this point, BHT lacks a connection to cancer, although Center for Science in the Public Interest still cautions exposure to it. Some data suggests that it may be a weak endocrine disruptor and affect the lungs, kidney, liver and thyroid.
Propyl gallate – is formed by the condensation of gallic acid and propanol. It’s a synthetic antioxidant that’s added to foods, cosmetics and pharmaceuticals to slow the breakdown of fat and oils. It’s often used in conjunction with BHA and BHT because of the synergistic effect they have with one another. Foods that typically have propyl gallate added to them include meat products, microwaveable popcorn, soup mixes, chewing gum, mayonnaise, and frozen meals. The FDA recognizes propyl gallate as being generally safe, but in other countries, it’s either been used on a very limited basis or completely banned. This is because some preliminary studies have suggested that propyl gallate may cause cancer (in several organs) in rats and be an endocrine disrupter. It’s been found to irritate the stomach and skin, affect breathing and cause kidney and liver problems. Center for Science in the Public Interest lists propyl gallate as a preservative that should be avoided.
Sodium nitrite and nitrate – are salts that help preserve cured and processed meats such as bacon, sausage, hotdogs, ham, deli meats, smoking fish and corned beef. Nitrites/nitrates help flavor the meat, suppresses botulinum bacteria and provide meat with its pinkish-red color. Without nitrites/nitrates, hotdogs, ham and bacon would be gray. Nitrites and nitrates are similar -- in fact, they’re often referred to as cousins. The difference is nitrites are synthetic and nitrates are natural. But in processed meats, nitrates slowly break down into nitrites.
Nitrites form nitrosamines, which can damage DNA and cause cancer. Processed meats have been linked to an increased risk of re**al cancer and there’s some evidence that processed meats may raise your risk for stomach cancer, according to MD Anderson.
The nitrite/nitrate situation in processed foods has improved over time. For example, food manufactures began adding vitamin C to processed meats, as it helps stop the formation of nitrosamines. They’ve also lowered the amounts of nitrites/nitrates used in meat. And some manufacturers began preserving meat with celery salt (which may have nitrates) or eliminated nitrites/nitrates altogether, e.g., nitrate-free bacon. To help lower your nitrosamine exposure in meat, you can:
Buy meat or bacon that’s organic or from a local source, like a farmer’s market.
Cook bacon at a lower heat and for a longer time without burning it.
Look for sodium nitrate E251 and sodium nitrite E250 on food labels.
Keep in mind, nitrates can occur naturally in food. Many vegetables, particularly spinach, Bok choy, lettuce and carrots are good sources of natural nitrates. But these nitrates are healthy and convert into nitric oxide, which helps improve circulation, blood pressure, hormone release and the transfer of information between nerve cells.
“Some experts believe our exposure to these preservatives through food is minimal, which it may be, However, the more foods and beverages you consume with these chemicals, the greater your exposure,” says Bernard Kaminetsky, MD, medical director, MDVIP. “If you’re interested in removing processed foods from your diet, talk to your doctor. They may be able to provide some guidance or refer you to a dietician.”
Don’t have a primary care doctor? Consider joining an MDVIP-affiliated practice. MDVIP-affiliated physicians have more time to help you in your pursuit of a healthier lifestyle, which can include a healthier diet. https://www.mdvip.com/doctor-search
