Center for Research on Ingredient Safety

Updated: May 28, 2020

What are nitrates and nitrites?

Nitrates and nitrites are chemicals found naturally in soil and water as part of the earth's nitrogen cycle. We find these ingredients naturally in many vegetables, and we add them to meat products to help keep them fresh.
 
Chemically they are expressed below:

• Nitrate: 1 nitrogen atom, bonded to 3 oxygen atoms: NO3-
• Nitrite: 1 nitrogen atom, bonded to 2 oxygen atoms: NO2-

Nitrates can be transformed into nitrites through digestion when bacteria in the mouth and enzymes in our body breakdown the nitrates into nitrites.
 
Nitrites typically transform into two distinct compounds in our body:

• Nitric oxide, which is good for human health.
• Nitrosamines, which can cause harm to human health depending on the level of exposure.

Where do I find these ingredients?

We can find naturally occurring nitrates and nitrates in water and vegetables, especially in leafy and root vegetables such as lettuce, beets, celery, carrots, and more. Around 80% of the nitrates and nitrites we consume are naturally occurring from the plants we eat.
 
We add synthetic and naturally derived nitrates and nitrites to many meat products such as hotdogs, bacon, sausages, and more to protect the food from harmful bacterial growth while increasing the umami flavor and giving the meat a red or pink color.

Are they bad for me?

Nitrates and nitrites are a vital component aiding our digestive system, and we find them in our saliva and blood. They help protect against specific types of bacteria, and they can transform into nitric oxide, which provides many health benefits such as lowering blood pressure.
 
Research shows that diets high in vegetables, including vegetables with naturally occurring nitrates and nitrites, are excellent for human health, and health professionals recommend these vegetable-rich diets.
 
Research also tells us that diets high in processed meats that typically contain nitrate and nitrite preservatives can harm our health, and we should eat them in moderation. As with most things, the dose makes the poison.

In which situations can they cause harm?

Meat contains proteins and amino acids naturally. When we need to preserve meats, we add nitrates and nitrites in small, regulated quantities to keep the food from spoiling prematurely.
 
We know that when we expose nitrates and nitrites to high heat in the presence of amino acids, they can transform into nitrosamines. Most nitrosamines are known carcinogens, which can lead to adverse health impacts.
 
For example, when cooking processed meats over high heat, such as grilling or high heat frying, many of the nitrites are transformed into these nitrosamines.
 
Over the years, we've made great strides in lowering the number of nitrosamines that can form during the cooking process by adding other ingredients such as Vitamin C, which inhibits the formation of nitrosamines. Additionally, the FDA regulates the number of nitrates and nitrites in processed foods, to ensure our exposure to these ingredients remains well within the safe levels.
Research also shows us that if we consume processed meats in moderation as part of an overall healthy diet, we are unlikely to experience long term adverse health impacts. Moderation is key.
 
It's important to note that when nitrates and nitrites enter drinking water in large quantities, they can cause significant harm to formula-fed infants under six months of age, and, in substantial amounts, they can harm children and adults. Nitrates and nitrites in drinking water is not a common problem and typically impacts individuals with untested, private water wells.

What else should I know about nitrates & nitrites?

Many companies have created "organic" and "natural" meat products. These products are not allowed to use synthetic ingredients such as nitrates and nitrites per USDA guidelines. However, without nitrate and nitrite preservatives, these products spoil quickly and could cause harm.
 
To keep organic and natural meat products safe, scientists have turned to plants rich in natural nitrates and nitrites such as celery, carrot, beet, spinach, and more. They process these plants into juices, powders, and other derived substances. Then, they add these naturally derived ingredients to the meat products with other naturally reactive ingredients that allow the formation of protective nitrites.
 
The level of nitrates and nitrites provided by natural sources can be less than or greater than synthetic nitrates and nitrites, as this varies greatly between products. However, that means these organic and natural meat products still retain the potential to produce nitrosamines when cooked at high heats because they still contain nitrites. The source of the nitrites does not matter when undergoing a chemical reaction.
 
It's essential to keep this in mind when grocery shopping because our food products, especially our meat food products, require preservatives to retain their quality. Whether you choose natural, organic, or traditional meat products, nitrates and nitrites will still be present in some form to keep our foods safe and fresh. 

The good news.

As we fire up our grills and make vegetable salads for our summer barbecues, we know that we can safely consume cured meats and veggies as long as we maintain moderation. The preservatives, both natural and synthetic, help keep our foods safe from harmful pathogens so we can enjoy our meals without worry.