Are food preservatives like sodium benzoate linked to cancer?

What's actually in it

Packaged foods often contain preservatives to keep them fresh longer. Some of the most common ones include sodium benzoate (found in soft drinks and condiments), potassium nitrite (found in processed meats like hot dogs and deli slices), and potassium sorbate (found in cheese, baked goods, and dried fruit). These chemicals stop bacteria and mold from growing, but they don't just disappear once you eat them.

What the research says

A 2026 study in the BMJ followed more than 100,000 adults for an average of seven years. Researchers tracked exactly what each person ate, including which preservatives were in their food and how much they consumed.

People who ate more potassium nitrite had a higher risk of cancer overall. The link was strongest for breast cancer. Nitrites can form compounds called nitrosamines in your body, and nitrosamines are known carcinogens.

Sodium benzoate was also tied to increased cancer risk in the study. So was potassium sorbate, though the connection was weaker.

This was a large, well-designed study, but it's observational. That means it shows a pattern, not proof that these chemicals directly cause cancer. Still, the size of the study and the consistency of the findings make it hard to ignore.

The simplest way to cut your exposure: eat fewer processed and packaged foods. Fresh or frozen fruits, vegetables, and meats don't need preservatives. When you do buy packaged food, check the label for nitrites, sodium benzoate, and potassium sorbate.