Nitrites. Fear the word! I am betting at some point in the endless ritual of perusing the internet, you have stumbled across the topic of nitrites/nitrates in food.
You might recall a headline like, “Did You Know Bacon is Slowly Killing You?” or maybe, “Eating Bacon is Just as Bad for You as Smoking.” “These claims came in response to the ruling by the International Agency for Research on Cancer (IARC) that classified nitrites, almost always added to bacon, as probably carcinogenic to humans. This may leave you wondering: Why add nitrites if it could have this possible outcome?
Nitrites are added for several reasons. They help with flavor development and color retention when added to cured meats. But the most important reason is food safety. Nitrites are an effective component in preventing Clostridium botulinum. This nasty bacteria produces a toxin called botulinum. It is the most lethal food toxin. A couple of nanograms—yes, nanograms—is enough to end any victim within hours.
Sometimes you might hear nitrites and nitrates referred to interchangeably. Nitrates, in meat, are reduced to nitrites. Nitrites are the active component in preventing botulinum. So before we march to headquarters of Big Bacon, we have to first ask ourselves, what is worse: a slight increase in the possibility of cancer risk or the immediate death caused by botulinum? We have to rationalize risks. This is always challenging for food. Our relationship with food is almost anything but rational.
As it stands, adding nitrites reduces foodborne illness risk from consumption of cured meats. But should we still continue to pursue alternatives that could offer a superior outcome? One option many have viewed as an alternative are products labeled as having “no added nitrites/nitrates.”
This claim is present because of the standard of identity associated with curing through the addition of nitrites. It is likely these products still contains nitrites, but from other sources. These products almost always contain celery juice. Guess what celery juice contains? Nitrites. Sometimes at even higher levels than the conventional version.
These alternatives are indirectly introducing the same chemical that the labeling states is not added. You may be surprised to learn that vegetables contain high levels of nitrites and nitrates naturally. Certain fruit and vegetable juices can contain nitrates above 3,000 parts per million (ppm). Processed meats usually have less than 100 ppm, so why is all the talk about nitrites in just meat? Nitrites are not actually the primary concern, the health risk comes from nitrosamines.
This compound is formed by combining nitrites, a specific amino acid from protein (typically asparagine), with heat. Guess what food has all three of those elements? Processed and cured meats. The risk of nitrosamines from vegetables or plant sources is less because amino acids are not as available to react with, and they are rarely subjected to the same temperatures as cooked meat. This is why the risk of nitrites/nitrates in vegetables is rarely discussed, even though they have as much as 60 times the levels found in meat.
While nitrosamines formed by the addition of nitrites do present a validated risk, it is good to put what we’ve learned from IARC’s ruling on nitrites in perspective. The organization has reviewed 989 agents. Only a single agent, Caprolactam (synthetic polymer used in nylon production), has been classified as probably not carcinogenic to humans. IARC claims “to make scientific, qualitative judgements on the evidence for or against carcinogenicity provided by the available data.” This is why the risk, from something such as the occupational hazard of being a barber, falls under the same category as malaria. The extent, or quantitative component, is not often included in their risk assessment.
The next time you are warned about a “silent killer” association to something in your diet, consider the full functionality or purpose of whatever is being discussed. The risk of X from Y is omnipresent with every aspect of our lives. Even many vitamins that are essential to life could present a risk at certain levels.
Someone could argue nitrites are saving lives by reducing the risk of foodborne illness. Others could argue that this compound presents a risk to health and is probably carcinogenic. Both groups would be correct in this case.