What Are Nitrates and Nitrites?

Suffice it to say if you’re eating fresh spinach, carrots, bok choy, and beets, you’re in the clear. There is less research on the potential effects that certain cooking methods have on nitrite levels in nitrate-containing veggies. But some research offers a clue. For example, stir-frying vegetables may result in more exposure to nitrites than boiling veggies, according to a study published in December 2021 in Foods. More studies on the effect of cooking veggies with nitrates, especially cooking veggies at high heat, are needed.

As for processed foods, steering completely clear of nitrates and nitrates can be hard to do even when you scrutinize food labels. But you still can shop and eat in ways that limit your exposure and minimize health risks of consuming foods with these compounds.

If you do just one thing, focus on limiting your consumption of processed meats.

“Probably the unhealthiest foods rich in nitrites are processed meats,” says Mingyang Song, MBBS, ScD, an assistant professor of clinical epidemiology and nutrition at the Harvard T.H. Chan School of Public Health in Boston.

There are several things to keep in mind when trying to minimize your exposure to processed meat, according to the University of Texas M.D. Anderson Cancer Center, including:

• Beware “nitrate-free” labels. This just means processed meats lack artificial nitrates, but they can still contain natural nitrates such as celery powder. These natural nitrates can still be harmful, according to M.D. Anderson.
• Realize red meat isn’t the only problem. Other meat can be, too. Chicken or turkey cold cuts most likely have nitrates, and so does turkey bacon and any other type of processed meat, M.D. Anderson notes.
• Check the sell-by date of your foods. Fresh meat expires in days, not weeks, and if it lasts more than a few days, it’s probably processed and has nitrates.

One other thing to consider is your water source. People who drink well water should have it tested for nitrates, especially if they live in an agricultural area where fertilizer runoff might contain these compounds, according to the CDC. Bottled water is best if well water hasn’t been tested yet.

Parents of newborns should also avoid feeding infants homemade foods that contain certain nitrate-rich vegetables like spinach, beets, green beans, squash, and carrots until babies are at least 6 months old, due to the risk of poisoning, according to Nationwide Children’s Hospital. Because solid foods are not recommended until 6 months old anyway, this shouldn’t be an issue. until babies are at least 3 months old, due to the risk of poisoning, the CDC advises. These newborns can still have commercially prepared baby food, including food with nitrate-containing veggies, and breast milk.

This risk of nitrate poisoning in newborns happens because babies have red blood cells — which are responsible for carrying oxygen through the body — with a limited ability to prevent a chain reaction caused by nitrates that impairs oxygen delivery. By the time they’re 3 to 6 months old, most babies make red blood cells capable of resisting this chain reaction, limiting the harm that nitrates can cause.