A new study has found that consuming preservatives commonly used in processed foods and beverages may be linked to an increased risk of certain cancers.
The study, published Jan. 7 in The BMJ, analyzed dietary and health data from more than 105,000 participants collected between 2009 and 2023. Researchers examined the impact of 17 food preservatives often added to extend shelf life and found that higher intake of several of those additives was associated with a greater risk of cancer compared with lower or no consumption.
Among the preservatives linked to increased cancer risk were potassium sorbate, potassium metabisulfite, sodium nitrite, potassium nitrate and acetic acid. Sorbates, which are used to prevent mold and bacterial growth, were associated with a 14% higher risk of overall cancer and a 26% higher risk of breast cancer. Sulfites, commonly found in fermented products such as wine and beer, were linked to a 12% increased risk of overall cancer.
Sodium nitrite, frequently used to preserve processed meats such as bacon and ham, was associated with a 32% increased risk of prostate cancer. A related compound, potassium nitrate, was linked to a 13% higher risk of overall cancer and a 22% increased risk of breast cancer, according to the study.
Researchers also identified major dietary sources of these preservatives. About 85% of sulfite intake came from alcoholic beverages, while 54% of nitrites and 80% of nitrates were derived from processed meats. Nearly half of propionate intake was traced to refined grains and breakfast cereals.
The study was observational and does not establish a direct cause-and-effect relationship. However, the authors said the findings are consistent with previous research linking highly processed foods to negative health outcomes.
“This study brings new insights for the future re-evaluation of the safety of these food additives by health agencies, considering the balance between benefit and risk for food preservation and cancer,” the authors wrote, adding that additional research is needed.
The preservatives identified in the study are currently classified by the U.S. Food and Drug Administration as “generally recognized as safe,” or GRAS. The FDA has previously re-evaluated substances on the GRAS list as new scientific evidence emerges.
In the meantime, researchers encouraged food manufacturers to reduce unnecessary use of preservatives and advised consumers to choose minimally processed foods when possible.
That recommendation aligns with recently released U.S. dietary guidelines from Health Secretary Robert F. Kennedy Jr., which emphasize whole and minimally processed foods. Some health experts, however, have expressed concern that the guidelines’ emphasis on protein and red meat could lead to increased consumption of processed meats, which have been linked to adverse health outcomes.
The World Health Organization has classified red and processed meats as carcinogenic, citing a clear association with colorectal cancer.
