What is Nitric Salt?
The term “nitric salt” is a general reference and does not correspond to a single chemical compound. Instead, it typically refers to the nitrate and nitrite salts used in food processing and other industries. The most common are sodium nitrite (NaNO2) and sodium nitrate (NaNO3). These compounds are a key ingredient in curing salts, often mixed with regular table salt, and are used to preserve foods like bacon, hot dogs, and ham. Their functions include inhibiting the growth of harmful bacteria, especially Clostridium botulinum, and developing the characteristic pink color and flavor of cured meats. While naturally occurring nitrates are abundant in vegetables like spinach and carrots, the side effects associated with "nitric salt" primarily pertain to the nitrites used as food additives and their reactions within the body.
Acute Side Effects: Poisoning and Methemoglobinemia
High-level, acute exposure to nitrites can be severely toxic, a condition that medical professionals call methemoglobinemia. This occurs when nitrites interfere with the blood's ability to transport oxygen throughout the body. The symptoms of acute nitrite poisoning are serious and require immediate medical attention.
Symptoms of Methemoglobinemia
Ingestion or inhalation of large quantities of sodium nitrite can lead to:
- Cyanosis: A bluish discoloration of the skin and lips due to lack of oxygen.
- Severe headaches and confusion.
- Nausea, vomiting, abdominal pain, and diarrhea.
- Dizziness, fatigue, and weakness.
- Rapid heart rate and difficulty breathing.
- In extreme cases, loss of consciousness, convulsions, collapse, and death.
Infants are particularly vulnerable to methemoglobinemia, sometimes referred to as “blue baby syndrome”. Their bodies are less efficient at converting methemoglobin back into normal hemoglobin. Contaminated well water containing high levels of nitrates can be a risk, especially if used to prepare infant formula.
Long-Term Health Risks Associated with Processed Meats
For most people, the risk from nitric salt doesn't come from acute poisoning but from the long-term, cumulative consumption of processed meats. Health organizations have expressed serious concerns about these products.
Cancer Risk from Nitrosamines
When nitrites are added to processed meats, they can react with amines under certain conditions to form N-nitroso compounds, including nitrosamines, which are known carcinogens. The formation of nitrosamines is particularly problematic when meat is cooked at high temperatures, such as frying or grilling. Nitrosamines are believed to be a major factor in the link between processed meats and certain cancers. The WHO's International Agency for Research on Cancer has classified processed meat as a Group 1 carcinogen, meaning there is sufficient evidence that it causes cancer, specifically colorectal cancer.
Cardiovascular Disease and Diabetes
High consumption of processed meats, which contain nitric salts, has also been consistently linked to an increased risk of cardiovascular disease (CVD) and type 2 diabetes. In a comprehensive review by the University of Oxford, each 50g daily portion of processed meat was found to increase the risk of coronary heart disease by 18%. This risk is attributed not only to the nitric salts but also to other components of processed meats, such as high saturated fat and sodium content.
The Source Matters: Vegetable Nitrates vs. Processed Meat Nitrites
It is crucial to differentiate between the nitrates found naturally in vegetables and the nitrites added to processed meats. While chemically similar, their effects on the body are vastly different due to the presence of other compounds in their sources.
| Feature | Nitrates in Vegetables | Nitrites in Processed Meats |
|---|---|---|
| Source | Naturally occurring in soil, absorbed by plants. | Added as a curing agent during processing. |
| Context | Present alongside antioxidants (Vitamin C), polyphenols, and fiber. | Present in close proximity to proteins and heme iron. |
| Health Impact | Can convert to beneficial nitric oxide, which supports cardiovascular health by dilating blood vessels and lowering blood pressure. | React with proteins and amines, especially during high-heat cooking, to form carcinogenic nitrosamines. |
| Associated Risk | Lower risk of forming harmful compounds; antioxidant presence inhibits nitrosamine formation. | Significantly higher risk of forming carcinogenic nitrosamines, contributing to cancer and other diseases. |
How to Reduce Risk from Nitric Salts
To mitigate the health risks associated with nitric salts, particularly from processed foods, consider the following strategies:
- Limit Processed Meat Intake: The simplest way to reduce exposure to food-additive nitrites is to eat less processed meat like bacon, ham, and sausages. The World Cancer Research Fund recommends eating very little, if any, processed meat.
- Choose Fresh Alternatives: Opt for fresh, unprocessed meats, poultry, and fish. When consuming red meat, stick to the recommended portion sizes.
- Embrace Vegetable Nitrates: Increase your consumption of nitrate-rich vegetables like spinach, beets, and celery. These foods provide beneficial nitrates and other protective nutrients.
- Check Water Quality: If you use well water, have it tested for nitrate levels, especially if there are infants in the household, as boiling water only concentrates nitrates.
- Look for Labels: Be aware that some organic processed meats use celery powder, a natural source of nitrates, as a curing agent. While organic, the conversion to nitrites can still occur.
Conclusion
While nitrates are naturally present and even beneficial in vegetables, the use of nitric salts like sodium nitrite in processed meats presents significant health concerns. Acute overexposure can lead to life-threatening methemoglobinemia, while chronic high intake from processed foods is linked to increased risks of cancer, heart disease, and diabetes due to the formation of nitrosamines. By understanding the critical distinction between nitrates in vegetables and nitrites in cured meats, consumers can make informed dietary choices. Limiting processed meat consumption and focusing on a diet rich in fruits and vegetables are key steps to reduce the associated risks and promote long-term health. For more information on the link between processed meat and cancer, refer to the World Health Organization's Q&A page WHO Q&A on Processed Meat and Cancer.
