Sodium nitrate and its cousin sodium nitrite are chemicals used to preserve meats. Cured meats including bacon, ham and various lunchmeats rely on nitrates to prevent the growth of harmful bacteria. While these chemicals are used to keep food safe, many question their health effects.
Food preservation initially relied on salt, fermentation, drying and canning. Before the age of refrigeration, these methods were used to keep foods from spoiling. Research about nitrates began in the 1920s, where it was found to effectively kill many strains of bacteria that other preservation methods missed.
Sodium nitrate and sodium nitrite are food additives commonly used in cured meat. Its main function is to inhibit clostridium botulinum bacteria from producing the toxin that causes botulism. Botulism is a life-threatening illness that results in paralysis and eventually death. Nitrate combined with salt is extremely effective at inhibiting the growth of clostridium botulinum. Sodium nitrate also contributes to the flavor and pink color of cured meats.
The safety of nitrates has been investigated since the 1970s and is still debated. The main concern is that it can form carcinogenic compounds called nitrosamines when added to meat products. Nitrosamines have been linked to bladder, colon, esophageal, and gastric cancers. In response, food manufacturers have developed techniques for minimizing the amount of nitrosamines formed during the processing of cured meat, however, they have not been eliminated.
Nitrates pose an additional risk by another mechanism. Upon degradation in the body, nitrates form highly reactive compounds that can damage bodily tissues, especially the lungs. Researchers have found that frequent intake of cured meat increases the risk of having lung problems including Chronic Obstructive Pulmonary Disease.
Others argue that nitrates are not harmful because they are a normal metabolite involved in a number of physiologic reactions. This includes regulating blood pressure, healing wounds, and immune response. Excess nitrite is eventually excreted through the urine.
Surprisingly vegetables naturally contain nitrate, which is a similar and less toxic cousin of nitrite. Some of the nitrate from vegetables is converted into nitrite, and therefore considered a metabolite of vegetables. However, the increased use of nitrogen-containing fertilizers has led to higher levels of nitrate in conventionally grown vegetables.
Some studies link sodium nitrate and sodium nitrite from cured meat to cancer and lung disease, while others claim that it is safe. After decades of research, there is still no consensus among the medical community. To stay on the safe side, keep intake of nitrate and nitrite to a minimum. Limit consumption of cured meat products to two to three servings per week. Alternatively, purchase meats that have not been cured or choose those that have no added nitrates or nitrites. In addition, purchase vegetables that have not been grown with chemical fertilizers to reduce nitrate ingestion.