Sodium nitrite, a common food preservative, is increasingly involved in suicides, particularly among young people.
Between 2019 and 2024, post-mortem analyses reveal a worrying upward trend, with a notable geographical concentration in Greater London and southeastern England. This development raises questions about access to this substance and the dissemination of dangerous information online.
Sodium nitrite is a chemical compound commonly used as a food preservative, particularly in processed meats, where it helps prevent bacterial growth and maintain color and flavor.
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Among these cases, men are the most affected, accounting for nearly two-thirds of recorded cases. The average age of victims is 28, with cases as young as 14. The study's researchers, published in
BMJ Public Health, analyzed 164 cases confirmed by coroners. In 87% of them, blood nitrite and nitrate levels were approximately 100 times higher than normal, indicating massive intentional ingestion.
The data show a sharp increase in cases after 2019, when specific tests for these compounds became available. However, researchers estimate that the actual number of deaths is likely underestimated, as these analyses are not systematic. The most affected age group is Millennials (38%) and Generation Z (33%), indicating a young profile in these suicides.
Access to online information detailing how to obtain and use sodium nitrite is being pointed out. This content, sometimes disguised as mental health advice, facilitates the act.
Concrete measures are proposed, such as making an antidote (methylene blue) available in ambulances. Professor Amrita Ahluwalia, lead researcher, emphasizes the urgency of restricting access to this chemical and limiting the spread of harmful content online.
Methemoglobinemia: a well-known toxic mechanism
Methemoglobinemia is a blood disorder where hemoglobin is transformed into methemoglobin, a form unable to bind oxygen. Normally, our blood contains less than 1% of this inactive form, but exposure to oxidizing agents like sodium nitrite can increase this level. When it exceeds 20%, tissue oxygenation becomes critical.
Symptoms appear quickly: headaches, fatigue, nausea, then bluish coloration of the skin (cyanosis). Beyond 50% methemoglobin, cardiac arrhythmias, seizures, and coma occur. Without treatment, death from cellular asphyxia can occur within hours.
The antidote is methylene blue (methylthioninium chloride), which reduces ferric ion to ferrous, restoring hemoglobin function. Administered intravenously, it works within an hour. The study's researchers argue for this treatment to be available in ambulances, as every minute counts after ingestion.