The Quick Answer: Preserved meats must contain nitrites to protect against pathogens like botulism. Minimize your intake to reduce your health risk; avoid them if you’re pregnant, diabetic, hypertensive, or have a familial cancer risk.
At a certain age, you begin to think about writing your life story, or at least a memoir to preserve a few treasured memories. My favorite moments revolve around the beautiful wife and our slightly above average kids, but backpacking trips into the Sierras would also be included. I have wonderful memories of being high in the mountains with friends, living very simply off what we could carry on our backs. The picture above was painted by my backpacking buddy, Doug Phelps, as good a man as you could hope to know. I post it as a memorial to his untimely death from cancer.
This morning I remembered camping by an alpine lake so pretty words couldn’t do it justice. We had used a pack animal so had the luxury of foods not normally carried, like the cured ham we had for dinner. The next morning we didn’t want to leave this Garden of Eden, but there was more to see so we set out, climbing a ridge with many switchbacks. I was unusually short of breath on the ascent, panting, almost asthmatic, and began to wonder what might be wrong. Years later, I may have learned the reason, thanks to a question asked by Greg, a reader of this blog.
Greg asked about processed meats, wanting to know what makes them even unhealthier than regular meat. This led to a study of how meat is cured, a practice with ancient origins. Though salt, sugar, and smoking all play a part in the preservation of meats there is one essential ingredient: nitrite. Whether added as nitrate (which becomes nitrite) or more directly, nitrite performs an essential service—it stops the growth of pathogens like C. botulinum, Staph. aureus, and the listeria species. Without nitrite, we would be limited to the short shelf life of refrigerated meats and miss the smell of bacon cooking on Saturday mornings.
Nitrite is a toxin, a few grams taken directly can be fatal. In the ‘70s it was theorized that nitrites caused cancer when the body converted them to nitrosamines. The role of nitrites in cancer has not been proven—this is typical of carcinogens, the actual process is complex and remains unproved—but there is strong evidence nitrites are a risk factor. A recent post noted studies linking processed meats to a higher risk of certain cancers, heart disease, and type-2 diabetes. Other studies add stomach cancer, childhood leukemia, brain cancer, and non-Hodgkins lymphoma. Add to that a role in hypertension, and diabetes.
I learned that nitrite also has short-term effects: it destroys red blood cells, and can cause headaches, and asthma-like breathing difficulties (though sensitivity varies among people). When I read about the latter, I remembered my prior trouble breathing when backpacking. Climbing high in the Sierras with a heavy backpack is a critical challenge of respiratory capacity and what seemed like asthma had followed a big ham dinner the night before. Backpackers take note: hold the preserved meats before difficult climbs.
Naturally Cured Meats
Because nitrite in preserved meats is a concern, some meat products are advertised as nitrate free, or “naturally preserved”, a condition for “organic” labeling. Do organic meats actually have less nitrites? Probably not, the nitrites are just added by different means. Nitrates and nitrites are common to all plants—this is logical, as the air we breathe is 78% nitrogen and nitrogen is involved in biological processes. So you can cure meat by using nitrates found in plants like celery; it’s trickery, but this form of nitrite is slipped into the ingredient list as celery powder, or simple hidden under natural flavors.
A 2009 study out of Texas A & M compared meat around the country, both conventionally and naturally (or organically) cured. The curing method made little difference—for all types of processed meats the levels of nitrates and nitrites averaged 37.1 and 4.5 ppm (parts per million) respectively, well below the FDA maximum of 200 ppm. If meat has a lower nitrite level, it likely has a higher sodium level (salt helps inhibit pathogens too) so you trade one problem for another.
Here are a few other additives commonly found in preserved meats:
• Sodium polyphosphates improve slicing and reduce spattering.
• Sodium lactate is a wide-spectrum antimicrobial.
• Sodium diacetate controls mold and buffers pH.
A Good Story
I like the way tradition has been helped by science here. Meat had been cured forever using salt. Ancient salts, less refined, included nitrates/nitrites. How? Plants receive nitrogen from the air; when plants decompose the nitrogen is transformed to nitrates (saltpeter, one of many forms, is potassium nitrate); bacterial action converts nitrates to nitrites, and all these find their way into streams and rivers and eventually the seas. So ancient sea salts used to preserve meat contained nitrates and nitrites.
As food was industrialized, and the role of nitrite understood, manufactured nitrates/nitrites were added without adequate limits. The FDA resolved this in 1926 by setting the 200 ppm limit. In the 1970s the role of nitrosamines in cancer was discovered. Separately, it was discovered that ascorbic acid (vitamin C) enhanced the effectiveness of nitrites in killing pathogens. So in 1973 the bacon limit for nitrite was reduced if a form of ascorbic acid was included. Overall, the level of nitrites in processed meats has steadily decreased since 1926.
So history and science have given us better preserved meats. This is a good story. Problem is the meat industry has defended whatever they were doing, even as nitrite levels were reduced. This defensiveness, combined with their political clout, has slowed the rate of progress. There is likely a better method for curing meat waiting to be discovered; the meat industry should improve their image by proactively contributing to the search.
The Bottom Line
If you enjoy the traditional preserved meats, those available now contain minimal preservatives. Our favorites include ham, bacon, and a few lunchmeats, but we eat very little. We’re going to make it a rule to eat less than one serving weekly. Budget wisdom: Because of their higher cost, minimizing processed meats improves your chance of staying within the family food budget.
Pregnant women are advised to avoid processed meats completely. If I had a family history of cancer I would avoid processed meats, per the American Institute for Cancer Research’s guidance; likewise for a risk of diabetes.
Please comment on how you reduce your exposure to preservatives like nitrite.