Pregnancy is a time of uncertainty for some mothers. Google gets used plenty when moms are looking up information about diet or medications or anything else that they may or may not be able to use while pregnant. I get asked occasionaly from friends and family about different OTC drugs they can or can’t use and the questions come in at the pharmacy regularly about what is appropriate.
One of the questions that I personally don’t get often is about nitrites and nitrates. Actually the question I think has only ever come from my wife and there is a lot of websites that discuss this ad nauseum. Most have come to the same conclusion: don’t consume nitrites and nitrates during pregnancy. Does this really hold water though?
First nitrites and nitrates are chemicals commonly found in foods, especially in deli meats, but also in veggies. They are useful because they allow for the preservation of meat as they inhibit bacterial growth and give certain meats a pink color. They are also used as a food preservative in general. Look at the ingredients list of just about any processed food and chances are you might see some nitrites.
As just mentioned, vegetables can actually have these compounds in them as well. It appears that antioxidants may prevent them from converting into nitrosamines which are thought to be cancer causing chemicals and just kind of nasty in general. Nitrotrates are created more in a stomach with a higher pH than normal. More of that in a bit.
Lets look and see what some of the science has to say about it.
Many observational or epidemiological studies have been done looking at this question. In a meta-analysis (large review of studies) showed that regular consumption of hot dogs and sausage was associated with increased risk of childhood brain tumor by 33% and 44% respectively.  This is relative risk.
Eating lots of hot dogs during pregnancy sounds like a bad idea to begin with, after all hotdogs aren’t exactly known for their health benefits. It would also be interesting to see if these numbers held true with homemade sausage. The researchers did note that study design limited the results but that relationship warrants further study.
I might add this study was epidemiological which gives us info to ask more questions but cannot prove causation. Thus we can’t look at this study and conclude that eating hot dogs or sausage while pregnant will increase the risk of childhood brain tumor.
Another study looked at nitrites, nitrates, and nitrosatable drugs (drugs that have an amine group on them and may become nitrosamines. Women who had taken nitrosatable drugs were 2.7 times more likely to have babies with neural tube defects than those women who didn’t take them while pregnant. 
There is a good list of drugs that are considered nitrosatable. I want to talk about 1 in particular that is over the counter. Remember a few paragraphs ago we said that nitrates are converted more in a higher pH? Well ranitidine (Zantac) is one of the drugs on this list. So not only does ranitidine have the potential to increase nitrites in the body, so too does it make conditions in the stomach for more production of nitrite from nitrate from the food a mom eats. Ranitidine is a common drug used in pregnancy for heartburn. Could it be that this drug could helps to create neural defects during pregnancy? I don’t know the answer but it certainly seems plausible.
This is a reason for not giving veggies like carrots to infants. They aren’t producing acid levels on par with adults.
Also from another study, women with the highest intake of nitrates and nitrites that also took nitrosatable drugs were 7.5 times more likely to birth a child with neural tube defects. This may be disconcerting to some because as many as 24% of US women use nitrosatable drugs during the 1st trimester of prenancy. 
As stated above, antioxidants seem to prevent the problems associated with neural tube defects and in one review women who took more than 200mg of vitamin C daily had reduced risk from neural tube defects.  This again isn’t conclusive but does point to the possibility that nitrosamines are causin problems other than cancer.
Yet another epidemiological study looked at brain tumors from mothers who had been interviewed about nitrite consumption from various foods. They found that risk increased if cured meats were eaten twice daily.  They also found risk was raised if no vitamins were taken, likely due to antioxidants like vitamin C.
Is There any Evidence Nitrites are OK?
Lets look at nitrites for a bit. The majority of nitrites that a person is exposed to are the nitrites found in your mouth. That’s right, your mouth. Bacteria in your mouth are producing it as you read this. Nitrates can also be made into nitric oxide which is beneficial in the arteries.
Nitrosamines are unlikely to form in the body, especially if there is sufficient antioxidant available. The stomach pH also is unlikely to be conducive to nitrosamine production. Bacon cooked in one food study showed that unless you are really cooking crispy bacon at high heat or even burning it, there is no detectable nitrosamines.  Commercially cured meats and bacon also include sodium ascorbate (a form of vitamin C) to prevent nitrosamines from being created.
I might add that the epidemiological studies didn’t tell much about vegetable and fruit intake. As both are loaded with antioxidants and other goodies it is possible that those eating more cured meats are also eating less vegetables which are loaded with folate. Folate of course is essential for neural tube development in kids. Is this a case of those who eat lots of meat don’t eat their veggies? I don’t know but it certainly seems like it could be.
In addition, most nitrate sources from the diet are from vegetables, not meat. And according to one review, nitrites mixing with stomach acid are bactericidal and may be part of our innate immunity.  
So should you avoid deli meats and other nitrite and nitrate containing foods while pregnant?
It’s hard to give a definitive answer. I tend to think it’s probably ok once in a while. I mean we should be eating vegetables regularly and they are filled with nitrates. Some will say that nitrates from veggies are different from nitrates in foods. People who say this missed chemistry class. Nitrate is NO3….Period! And as already shown, veggies contain antioxidants which prevent nitrosamine production.
When a woman is pregnant she should be striving for optimal nutrition, just like when she’s not pregnant. I don’t think a woman should only eat healthy while pregnant. Good nutrition can mean the difference of fertility or non fertility for some women. Did my wife have some cured deli meats and sausage while pregnant? Yup, but not every day. Did she only consume those? Nope. Did she make sure here veggie intake and vitamin intake was adequate? Yup. All things in moderation. That said if you’re still fearful, then don’t eat them. You don’t have to for a healthy diet. Regular meat is great, especially the grass fed beef.
1.Huncharek, Michael, and Bruce Kupelnick. “A meta-analysis of maternal cured meat consumption during pregnancy and the risk of childhood brain tumors.” Neuroepidemiology 23.1-2 (2004): 78-84.
2.Brender, Jean D., et al. “Dietary nitrites and nitrates, nitrosatable drugs, and neural tube defects.” Epidemiology 15.3 (2004): 330-336.
3.Brender, Jean D., et al. “Prevalence and patterns of nitrosatable drug use among US women during early pregnancy.” Birth Defects Research Part A: Clinical and Molecular Teratology 91.4 (2011): 258-264.
4.Brender, Jean, et al. “Intake of nitrates and nitrites and birth defects in offspring.” Epidemiology 15.4 (2004): S184.
5.Preston-Martin, Susan, et al. “Maternal consumption of cured meats and vitamins in relation to pediatric brain tumors.” Cancer Epidemiology Biomarkers & Prevention 5.8 (1996): 599-605.
6.Pensabene, J. W., et al. “Effect of frying and other cooking conditions on nitrosopyrrolidine formation in bacon.” Journal of food science 39.2 (1974): 314-316.
7.Archer, Douglas L. “Evidence that ingested nitrate and nitrite are beneficial to health.” Journal of Food Protection® 65.5 (2002): 872-875.
8.McKnight, G. M., et al. “Dietary nitrate in man: friend or foe?.” British Journal of Nutrition 81.05 (1999): 349-358.
Disclaimer: All info on this website is for education purposes only. Any dietary or lifestyle changes that readers want to make should be done with the guidance of a competent medical practitioner. The author assumes no responsibility nor liability for the use or dissemination of this information. Anyone who chooses to apply this information for their own personal use does so at their own risk.