A new French study, published in French on Univadis, has found that consumption of nitrites and nitrates is associated with an increased risk of cancer, according to Medscape.

Researchers looked at data from more than 100,000 individuals and found that those who frequently consumed products containing nitrates had a 25% risk of developing breast cancer. They also found that those who frequently consumed food products containing nitrites were at 60% of developing prostate cancer.

However, they did not find any association between increased cancer risk and exposure to natural sources of nitrites and nitrates. These compounds occur naturally in water and soils. However, they are also used as preservatives in processed meats.

The findings are yet to be confirmed by other large-scale prospective studies, but they do call for a potential precautionary ban on the use of these preservatives.

Public health experts in various countries have already recommended limiting the consumption of food products containing these controversial additives.

Of the 101,056 participants enrolled, more than 78% were women. Of those, more than 3300 incident cases of cancer were diagnosed during the study period.

The participants who largely consumed products containing nitrates had a 24% higher risk of developing breast cancer, particularly before menopause compared to those who did not consume foods containing these additives.

In addition, the researchers found that the risk of prostate cancer was increased by 58%, particularly in those who consumed foods containing sodium nitrite.

The authors found no significant risk of colorectal cancer in participants who consumed foods that contained either nitrates or nitrites. They hypothesized that the study lacked statistical power for these latter analyses.

Considering the findings, the investigators suggest that these additives may “lead to the formation of N-nitroso compounds, which are potentially carcinogenic substances for humans.”

They also did not find any association between the consumption of nitrites or nitrates from natural sources and the risk of cancer.