Jan 08 2018

Nitrite Free Bacon

A Northern Irish food company, Finnebrogue, is offering what it calls “Naked Bacon” – free from chemical preservatives that contain nitrites. But would such bacon actually be more healthful? And what is the deal with nitrites in food?

Sodium nitrite (NaNO2) is a salt containing sodium, one nitrogen, and two oxygen atoms. Nitrate is similar but contains three oxygen atoms (NaNO3). Nitrites are oxidized to nitrates when exposed to the air. Nitrates can also be converted into nitrite in the GI tract. This is why we often talk about the two in food interchangeably.

Sodium nitrite serves a critical function in some foods – it is a good preservative that inhibits the growth of bacteria, specifically C. botulinum, the bacteria that causes botulism. It is therefore incredibly important to food safety, and removing it from meat products could therefore have the unintended consequence of increasing food poisoning.

What are the health effects of consuming sodium nitrite? Much of it is converted into nitric oxide, which is not only harmless, it serves several important roles in the body. One effect is to dilate blood vessels, and therefore can serve to lower blood pressure. In addition:

This effect is associated with a reduced risk regarding cardiovascular disease, myocardial infarction, and stroke. Moreover, dietary nitrate has been associated with beneficial effects in patients with gastric ulcer, renal failure, or metabolic syndrome.

The health concern is that nitrites can also be converted to nitrosamine compounds, which are probably carcinogenic. The amount of nitrites in food converted to nitrosamines is reduced by certain other food substances, such as vitamin C. Therefore, some food manufacturers have been adding vitamin C to food that also contain sodium nitrite.

There is also some evidence that cooking at very high heat can increase the formation of nitrosamines, and so this can also be avoided to minimize this conversion.

It is revealing also to point out what the sources of consumed nitrites/nitrates are. Much of the discussion focuses around sodium nitrite added to meats and other foods as a preservative. However. 80% of the nitrates you will consume in food come from fruits and vegetables. Nitrites are also made in the saliva, which is another significant source.

Contribution from preserved meats is about 10% – depending on your diet, of course. But even the most dedicated meat eater will still get a minority of their nitrites from cured meat.

What about the link between sodium nitrite and cancer? The evidence here is fairly complex and mostly observational. Many studies compare cohorts with the highest and lowest daily meat intake and find mixed results. Some datasets show a slight increase in pancreatic cancer and some GI cancers, but also reduced stomach cancer.

However, more recent research has called these associations into question. The problem with much of the prior research (in addition to being observational) is that it did not control well for many variables. If you look at meat consumption, for example, what aspect of the meat is causing any observed effect, and is it related to other dietary factors that just go along with high meat consumption?

A recent review concludes:

A critical review of the animal toxicology literature of nitrite indicates that in the absence of co-administration of a carcinogenic nitrosamine precursor, there is no evidence for carcinogenesis. Newly published prospective epidemiological cohort studies indicate that there is no association between estimated intake of nitrite and nitrate in the diet and stomach cancer.

So without the nitrosamine, consuming nitrites/nitrates is probably not associated with cancer at all, and has many known health benefits.

What the average consumer can make of all this is a few bottom lines: First, it is still the best advice to eat everything in moderation. The only studies that do show a negative health effect from consuming red or cured meats only finds such results in the highest meat consumption category. So basically, don’t eat a pound of bacon every day (literally, that is what it takes) and you will probably be fine.

Further, nitrites specifically have been unfairly maligned. Their story is much more complex, and overall we should look at nitrites/nitrates as having positive health effects. Remember – they mostly come from fruits and vegetables, and diets high in vegetable nitrates have been shown to be healthful.

Sodium nitrite specifically is an important food preservative, and we should not avoid its use over an unjustified fear.

What about the nitrite-free bacon? This is a good example of how food fears based on outdated, preliminary, or incomplete information can lead to bad eating decisions. First, many products touting themselves as not using added sodium nitrite, or avoiding chemical preservatives, actually do contain nitrites. The makers of Naked Bacon, for example, claim:

Finnebrogue said it worked with a Spanish chemist to develop the new flavouring from natural Mediterranean fruit and spice extracts and apply it to British bacon for the first time.

I wonder if those fruit and spice extracts contain sodium nitrite? That is often the case with similar products – they use the “appeal to nature” fallacy to imply their products are better because they use only natural ingredients. The source of the sodium nitrite, however, has zero effect on its health effects.

But thinking that your bacon is healthier may lead to consuming more fat and calories. This is the fallacy of blaming specific ingredients or types of food for being “bad” and thinking that avoiding them will make your diet magically healthy. Companies are quick to exploit this, with, for example “low fat” products that are loaded with sugar. Such products are often sold as “guilt free” but this is a scam.

Again – just eat a variety of foods in moderation, make sure you get enough fruits and vegetables, and watch your total caloric intake. Don’t be lulled into a false sense of security by thinking you are eating a “superfood” or “guilt-free” food.

17 responses so far

17 thoughts on “Nitrite Free Bacon”

  1. Rogue Medic says:

    But I need something to consume with my raw water!

    You’re just trying to force all of us onto your brethairian diet, so you can make the big money selling us air to eat.


  2. Chiliwilly says:

    Celery extract is a common source of nitrite used as a “natural” alternative in processed meats. Functionally, it’s the same, and the the limit of sodium nitrite from any source is typically 200 parts per million.

  3. Kawarthajon says:

    My understanding (very limited at best) is that the “sodium” in the “sodium nitrites” is also a problem. We North Americans tend to eat far too much sodium on average, which can lead to a lot of health problems and lower life expectancy. I have tried to find lower sodium meats to eat to lower my blood pressure, but the only option seems to be cooking fresh meat myself.

  4. daedalus2u says:

    I work in nitric oxide research (at AOBiome), so I am very familiar with nitrate and nitrite controversies. We are focused on commensal bacteria that produce nitrite on the skin by oxidation of ammonia in sweat.

    This review is a fair and accurate assessment of the state of the science behind nitrite. I am unaware of any well done research that suggests that nitrate in the diet is harmful. The risks of methemoglobinemia (blue baby syndrome) from nitrate in drinking water are overblown (in my opinion), and most likely are only due to using water contaminated with both bacteria and nitrate to make formula. The substrates in the formula are metabolized by the bacteria using nitrate as an electron acceptor forming nitrite (and bacterial biomass and toxins).

    There is lots of thought in the nitric oxide research community that the positive health effects of green leafy vegetables are due to the nitrate they contain.

    Nitrate in the diet is well absorbed and is concentrated ~10x over plasma levels into saliva, where it can reach levels of 10 mM/L. There are commensal bacteria on the tongue which reduce that salivary nitrate to nitrite which can also reach ~10 mM/L. When that saliva is swallowed, it is reduced to NO in the stomach by the low pH, where NO levels can reach ~100 ppm.

    I am pretty sure that “Naked Bacon” is all marketing hype. The characteristic color of bacon is due to nitrosyl heme; where the heme of myoglobin in the meat is coordinated to NO, producing the characteristic color. That red color is similar to the red color of oxyhemoglobin, and also similar to the red color of methemoglobin. Lately people have been using carbon monoxide to treat meat which gives it the characteristic red color of carboxymyoglobin, which is also red. Distinguishing between these different hemoglobin compounds can be done optically, and is the technology behind some pulse oximeters that also determine methemoglobin, deoxyhemoglobin, oxyhemoglobin and carboxyhemoglobin, important for fire department first responders.

    Adding nitrate to meat to preserve it goes back to antiquity. Many of the “spices” added during sausage production contain nitrate. Green leafy vegetables are a good source of nitrate, typically they contain a few thousand ppm nitrate (wet weight). When wet spices are dried, the nitrate levels can reach into the percent range. Dried celery powder is a common “spice”, likely added for its nitrate content, because celery doesn’t have a strong flavor.

    That nitrate is reduced to nitrite by enzymatic and non-enzymatic reactions (denatured heme acts as a nitrate reductase), and also to NO. Lots of plants have nitrate reductases (plants absorb nitrogen as nitrate, concentrate it in their tissues, and then reduce it to ammonia to form proteins).

    Naked Bacon is also “smoked”. NO and NOx are produced during smoldering combustion (along with carcinogenic tars) and that NO and NOx very likely generates nitrosyl hemes in the smoked meat too.

    On the website they also make a big deal out of not using phosphates or water. Phosphates and water are also completely natural constituents of food and have no adverse health effects as part of a normal diet. They use “sea salt”, instead of “heavily processed salt” (read purified salt).

  5. Lenala says:

    The various gimmicky and plain misleading food advertisements (nitrate-free, organic, natural, etc) drive me nuts. Especially now that I’ve been getting myself more into the habit to paying attention to labels (been trying to reduce sodium intake to control high blood pressure). I love it (sarcasm) how companies for the most part completely ignore focusing on useful dietary information. I would love to be able to quickly eyeball low sodium options vs having to turn over every single package/container and squint to find the sodium content.
    What really has been frustrating about this process is that unfortunately, a lot of the lower sodium options for things I don’t have time to prepare from scratch at home are also the overpriced, GMO-free, organic foods. Wish there was a way I could let them know that I’m only picking this up for the low-sodium, not the other crap on the label. *grumble*

  6. Reticent Arc says:

    I am entirely unqualified to fully grasp everything in this subject but your post was very interesting. However I believe their bacon is unsmoked, probably for the reasons you stated in your post.

  7. BBBlue says:

    Thanks daedalus2u, very interesting. Lot’s of interest in nitrate contamination of groundwater in my neck of the woods.

  8. BillyJoe7 says:

    Yes, nice summary from both SN and D2U.

    Nothing to add except an amusing coincidence. And I love coincidences.

    After my run this morning, I was preparing a breakfast of bacon and eggs on toast when my son mentioned that the nitrate in bacon causes bowel cancer. The first coincidence is that I can’t remember the last time I had bacon and eggs for breakfast. I usually can’t eat anything other than porridge and fruit at this time of the day. So I asked him how much I would have to eat to increase my base line risk of getting bowel cancer. He didn’t know. So then I sat down at the table with my plate of bacon and eggs and flick on my iPad to see if there’s a new post in the Neurologica blog. Surprise: “Nitrite Free Bacon”! Yes, so it’s nitrite and not nitrate but, of course, it doesn’t matter because nitrite exposed to air becomes nitrate and the GIT converts nitrate to nitrite (and NO). And the carcinogen is actually nitrosamine and you need lots to increase your risk.

    I narrated all the information in the post to my son as I was reading it and he was quite impressed how it was all so nicely put together. So, kudos, Steven, for that “nicely put together” post!

  9. Nitpicking says:

    I had largely stopped eating bacon for breakfast a while back, probably (I didn’t consciously think it out in detail) partly because of the whole “processed meat” thing. Maybe I’ll bring it back.

    Of course bacon fat is about 50% monounsaturated, which according to the last decade’s fad is the healthiest thing in the world. (It’s also about 40% saturated, which is still not good but not as bad as the trans fats, which bacon fat has none of.)

  10. jt512 says:

    The only studies that do show a negative health effect from consuming red or cured meats only finds such results in the highest meat consumption category. So basically, don’t eat a pound of bacon every day (literally, that is what it takes) and you will probably be fine.

    That’s false. Pan et al (2012) found a linear dose-response relationship between processed red meat consumption and all-cause mortality in a combined analysis of the Health Professionals Follow-Up Study and the Nurses Health Study. The relative risks for each quintile of intake compared with the first were 1.00, 1.05, 1.11, 1.15, and 1.23. Median intake for each quintile (HPFS cohort) was .02, .13, .21, .39, and, .74 servings per day. Compared with the first quintile, the risk for each of the 2nd through 5th quintiles was statistically significant. One serving of processed red meat was defined to be 2 pieces of bacon (28 g), 1 hot dog (45 g), etc. So it would be literally more accurate to say that you literally only have to eat about 3 g of bacon a day than 1 pound a day, to have a detectable increase in health risk.

    Similar results were found by Wang et al (2016) in a meta-analysis of 17 cohort studies. Interestingly, the results for processed red meat and cancer were extremely consistent across studies (I^2 = 0).

    Pan et al (2012). Red Meat Consumption and Mortality: Results from Two Prospective Cohort Studies. Arch Int Med 172.

    Wang et al (2015). Red and processed meat consumption and mortality: dose–response meta-analysis of prospective cohort studies. Public Health Nutrition 19(5).

  11. jt512 says:

    The correct journal year for Wang et al, above, is 2015.

  12. SleepyJean says:

    What causes the headache in eating these meats, bacon/ bologna/salami. I assumed it was the sodium nitrates?

  13. trumpproctor says:

    Especially now that I’ve been getting myself more into the habit to paying attention to labels (been trying to reduce sodium intake to control high blood pressure).

    I’ve always wanted to replace the “calories” with amount of exercise the average person would have to do to burn them off on labels. I think seeing 200 calories for a couple of cookies, the average person has no idea what that really means. But if alongside the 200 calories it listed that you would have to do high impact aerobics for 24 minutes to burn off those 200 calories, it’s easier to put the cookies back on the shelf, or maybe only eat half of ONE cookie, rather than 2 or more cookies.

  14. SleepyJean says:

    How about the hot dog headache?

  15. BillyJoe7 says:

    …or a Monkee headache: https://m.youtube.com/watch?v=_7-i_hSwxMc 🙂

  16. Sylak says:

    It’s like people concerned with preservatives in wine. Vague fear of preservatives while consuming a known toxic, but yummy, cancerigenic compound. Preservatives like vaccin are victims of their success. People don’t remember the tons of spoiled food or people being sick a lot more often because of food born illness. Preservatives had a beneficial impact on human health. But aaaah chemicals!

  17. SleepyJean says:

    There are sulfite free wines available for purchase and made in the USA.

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