Common Food Preservatives Linked to Cancer, Diabetes Risk

CAUSE: Two major French studies tracking over 100 000 people suggest certain widely used preservatives—especially nitrites in processed meats—may be linked to a higher risk of cancer and type 2 diabetes, though researchers stress the findings do not prove direct cause and effect…

By Own Correspondent

Eating certain common food preservatives may be linked to a slightly higher risk of developing cancer and type 2 diabetes later in life, according to two large French studies published on Thursday.

However, independent experts have urged caution, noting that observational studies cannot prove a direct cause-and-effect relationship and that more research is needed.

The first study, published in The BMJ, reported “multiple associations” between preservatives widely used in industrial foods and beverages on the European market and higher rates of overall cancer, as well as breast and prostate cancers.

Among the preservatives flagged were nitrites and nitrates, commonly used to cure processed meats such as ham, bacon and sausages.

The second study, published in Nature Communications, also found an association between consuming certain additives and an increased likelihood of developing type 2 diabetes.

Both studies draw from an ongoing long-term research project in which more than 100,000 French participants regularly complete detailed questionnaires about their diet.

French epidemiologist Mathilde Touvier, who supervised both studies, told AFP that consuming foods containing preservatives does not mean someone will immediately develop cancer.

“But we need to limit how much we are exposed to these products,” she said. Touvier added that the takeaway for shoppers is to choose the least processed foods when purchasing groceries.

In the cancer study, the strongest link was found between sodium nitrite and prostate cancer, with an estimated risk increase of about one-third. Researchers stressed that while notable, the rise in risk remains moderate. For comparison, heavy smoking increases lung cancer risk more than fifteenfold.

Meanwhile, the diabetes study found that potassium sorbate—used to prevent mold and bacterial growth in food and beverages—was associated with roughly double the risk of developing diabetes.

Researchers not involved in the studies praised their large sample sizes and robust methodology, but said it was too early for consumers to make major dietary changes based solely on these findings.

Tom Sanders, a nutrition expert at King’s College London, warned the results could reflect “an inability to completely correct for other factors” already known to raise disease risk.

For example, processed meat and alcohol are both strongly associated with increased cancer rates. Sanders suggested that in some cases it may not be preservatives such as sodium metabisulphite—which is used in winemaking to kill yeast—but alcohol consumption itself that contributes to cancer risk.

Still, Sanders said one possible public health measure could be warning labels on products that contain nitrates or nitrites.

The studies were published just days after the UK announced a ban on daytime television, radio and online advertising for unhealthy foods and drinks high in fat, salt and sugar. – Science X