What to know about foods with nitrates and nitrites

What do deli meats have in common with leafy greens?

Aside from the fact that both foods might be included in a sandwich, they also contain nitrates and nitrites.

But what exactly are nitrates and nitrites? Are they good or bad for you? And haven’t they been linked to cancer?

We asked clinical dietitian Katie Greenhill what we should know about foods with nitrates and nitrites. 

What are nitrates and nitrites? 

Nitrates and nitrites look similar, not just in the English language, but also molecularly. 

“Nitrates and nitrites are simple compounds made of nitrogen and oxygen,” Greenhill says.

Nitrates and nitrites are made of the same elements but structured differently: nitrate is NO3- and nitrite is NO2-.  

The body produces nitrate, but it can also come from sources like food, medication or groundwater, Greenhill says. 

What foods contain nitrates and nitrites?

Foods that contain nitrates and nitrites include cured meats, leafy greens and other vegetables.

Some cured meats add nitrates or nitrites to keep them fresh for longer. These include: 

• Bacon
• Bologna
• Canned meat
• Corned beef
• Deli meat
• Ham
• Hot dogs
• Pepperoni
• Salami
• Sausages

Some vegetables naturally contain nitrates and nitrites. These include:

• Broccoli
• Cabbage
• Carrot
• Cauliflower
• Celery
• Cucumber
• Endive
• Fennel
• Leek
• Lettuce
• Parsley
• Pumpkin
• Red beetroot
• Spinach
  

Do foods with nitrates and nitrites have benefits?

When you eat foods containing nitrates and nitrites, the body converts them into nitric oxide.

Nitric oxide has a variety of roles in the body. Greenhill says these include increasing blood flow, decreasing blood pressure, promoting heart health, helping to release a variety of hormones and sending signals throughout the body.

Additionally, Greenhill says some studies have found that nitric oxide supplements can improve exercise performance, benefit the respiratory system and help the body heal.  

Are foods with nitrates and nitrites safe to eat?

Eating processed meats like the deli meats listed above increases your risk for rectal cancer. There is also some evidence that eating foods with nitrates and nitrites may sometimes be linked to stomach cancer.

Because of this risk, Greenhill recommends limiting processed meat. If you choose to eat processed meats, opt for those that say ‘nitrate-free’ or ‘nitrite-free’ on the packaging.

“We should aim to limit consumption of processed meats that are rich in nitrate and nitrite,” she says. 

But how is it possible that some foods that contain nitrates and nitrites have health benefits while others are potential carcinogens?

This is due to nitrosation. Greenhill describes nitrosation as a process that creates carcinogens from nitrates and nitrites. She explains that antioxidants, like Vitamins C and E, stop nitrosation.

While processed meat doesn’t include antioxidants to stop this process, foods like collard greens, spinach and pumpkin contain both antioxidants and nitrates. This means they offer the health benefits of nitric oxide while canceling out nitrosation.

“We should not limit these healthy sources of nitrates due to the health benefits of nitric oxide in the body and the multitude of benefits of eating fruits and vegetables,” she says. “Our bodies need nitrogen and nitric oxide to function properly, but overconsumption, especially of processed meats, can lead to negative health implications. In general, consuming a balanced diet with a variety of fruits and vegetables should be the priority.”

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