Chapter 17.01: Finally – From Mummies to Nitrosamines

Introduction to Bacon & the Art of Living

The story of bacon is set in the late 1800s and early 1900s when most of the important developments in bacon took place. The plotline takes place in the 2000s with each character referring to a real person and actual events. The theme is a kind of “steampunk” where modern mannerisms, speech, clothes and practices are superimposed on a historical setting.  Modern people interact with old historical figures with all the historical and cultural bias that goes with this.


Finally – Finally – From Mummies to Nitrosamines

October 1990

How I discovered the Value of Nitrate, Nitrite and Nitric Oxide to Human Health

It was my search for the original location where meat curing was turned into an art form that made me look at the use of salt in meat preservation which predates the use of nitrogen salts. The general consideration of salt led me to mummification which took me to natural deposits of nitrate in the Atacama Desert in South America and the Turfan Depression in the West of China. In searching for supporting evidence of the general development of technology related to nitrates, I happened upon a very clear and effective remedy from this region which used nitrate, a cure so revolutionary that it was only finally understood by science in the 1980s which unlocked the reality of the absolutely key role of nitrate, nitrite and nitric oxide in human physiology. So, in re-capping the progression of my search for the location of the birthplace of nitrate curing of meat, I am actually telling the story of my discovery of the value of nitrite, nitrate and nitric oxide to human existence and health.

The Story at a Glance

My quest started with a consideration of salt. My interest is in its use as a meat preservative. When did this start and how and what are its functional benefits? Most of this has been dealt with in Chapter 12.10: Meat Curing – A Review, but I left an important link out in that discussion namely a realisation that studying mummies and mummification technology through the ages may be a very productive way of searching for the oldest known meat preservation technology and the use of salts at a time before writing was invented. I applied this thinking and did a survey of the oldest mummies on earth which yielded the most startling two results.

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A semi-natural mummy in Chile’s Atacama Desert

The oldest mummies on earth, dating from around 7000 BCE are the Chinchorro mummies from the one place on earth that is at the same time the dryest and is replete with the highest concentration of natural sodium nitrate, the Atacama Desert from Chile and Peru!  What makes this startling is that sodium nitrate has been the curing agent of choice for meat until it was replaced after World War 1 by sodium nitrite. I always thought that the use of sodium nitrate in meat curing became popular due to the cured colour it imparts to meat and that its preserving ability was a secondary application. I also thought that its widespread use was a very recent development that reached a height in Europe at the end of the 1800s.  Following my logic about mummification technology, I was certainly not expecting a date of 7000 BCE for a probable use of sodium nitrate in meat curing.

I turned my attention to Asia where, in an iconic review article from Binkerd and Kolari (1975), they claim that the use of nitrates in the curing of meat was first used as meat preservative “in the saline deserts of Hither Asia and in coastal areas.” They say that “desert salts contained nitrates and borax as impurities” and the discovery was accidental when they actually thought they use ordinary sea or bay salt (sodium chloride).  I wanted to examine the veracity of their claims.

What I discovered was startling, that curing technology was developed into an art form between a particular location in the far western regions of present-day China and the nations living around the Black Sea and the Caucasus Mountains.

The Turfan region in Western China had a major role to play in the story of the development of meat curing into an art. The oldest mummies in China is found in the Taklimakan Desert, in the Tarim Basin. Right here, in the region where the mummies are found, in the Turpan-Hami Basin, massive nitrate ore fields, close in proximity to the Tarim Basin exist.  Nitrate deposits, so massive that it is estimated to be at least 2.5 billion tonnes and comparable in scale to the Atacama Desert super-scale nitrate deposit in Chile.

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A Tarim mummy

At the graves near Loulan, one of the bodies was subjected to radiocarbon dating which indicated that she died about 1200 BCE. In the oldest cemetery so far discovered, the Small River Cemetery, mummies were discovered which carbon tests, done at Beijing University, show to be 3980 years old. This takes the known date for meat preservation, by our logic of linking it with mummification, to almost 4000 years ago in China. The logic is that people seeing this would have started to experiment with the possible causes for the natural mummification which would have included the salts of the area.

The two areas in the Atacama Desert and the Taklimakan Desert in China share a striking similarity in weather. They are both some of the aridest regions on earth.  A second factor that plaid a role in natural mummification is rapid freezing due to extreme cold conditions in the winter and then, of course, the very high sodium chloride content of the soil.

I honed in on this region in China for its geographical importance as being on the important Silk Road connecting Asia with the Middle East and Europe. I asked if there is any evidence of the development of sophisticated thinking pertaining to the use of sodium nitrate salt from this particular region.  My reasoning is that if meat curing as an art developed here, that would have been a springboard for the development of related applications.

The results of my enquiry have been nothing less than startling and leave me with little doubt that I have identified one of the locations on earth from where the art of curing meat developed and was spread into Europe and back into Asia.  Not that they were the only ones who would have discovered this. I am convinced the ancients in the Atacama Desert would have easily made the same link with meat preservation but it was here, in China’s Western front, on the Silk Road, where a level of sophistication in thought related to the application of sodium nitrate developed that is unrivalled, as far as I am aware off, by any other location on earth.

The first factor in favour of the Tarim Bason for the birthplace of curing technology that was spread into Europe is then the enormous natural deposits of sodium nitrate. Secondly, you have the mummies which are something that observant ancients would have noticed almost immediately. It won’t take you 4000 years to realise that something extraordinary is happening with the corpses. The third fact relates to the level of sophistication in the application of sodium nitrate.

The clue of such sophistication of thought comes to us in the discovery of an ancient medical prescription dating from some time between CE 456 and 536, during the life of the famous Daoist alchemist and physician Toa Hongjing in a cave close to the city of Dunhuang, right in our area of interest which we discussed in Chapter 12.06: From Sea to Deserts – Sal Ammoniac, Urine and Horse Sweat.

Allow me to recap. The text describes the treatment of a condition identified as a case of severe angina, i.e. restricted blood flow due to the narrowing of the cardiac arteries.  The treatment was to place saltpetre (potassium nitrate) under the tongue.

The basic curing pathway that alleviates the condition by the ancient prescription is a reduction of the nitrate through bacteria under the tongue to nitrite which is rapidly absorbed into the blood vessels in the mouth, bypassing the stomach, and transported by the blood, the nitrite is converted to nitric oxide and acts to alleviate the symptoms described in the texts.

The role of nitric oxide as a vasodilator was, amazingly, only discovered in 1987 simultaneously by a group of researchers at the Wellcome Research Laboratories in Beckenham led by Professor Salvador Moncada and by a group in the USA led by Professor Louis Ignarro. So momentous was this discovery that the 1998 Nobel Prize in Physiology and Medicine was awarded for the work. Once nitric oxide was identified as playing a role in physiological processes, it was found to be involved in many processes from inflammation to crying. So, here we have a text, detailing a medical prescription in the 5th and 6th century of the Christan Era, from China, that has only been fully understood by modern science in 1987!  This by itself is an astounding fact!

It gets even more startling. It turns out that this exact reaction sequence of nitrate ion that is reduced to nitrite through bacterial reduction and changed to nitric oxide, along with the influence of acidity and various reductants on the speed of the process is something that is well-known in meat science. Humphrey Davy, in 1812 (cited by Hermann, 1865) was the first one to note the action of nitric oxide upon haemoglobin. On 7 May 1868, Dr Arthur Gamgee from the University of Edinburgh, brother of the famous veterinarian, Professor John Gamgee (who contributed to the attempt to find ways to preserve whole carcasses during a voyage between Australia and Britain), published a groundbreaking article entitled, “On the action of nitrites on the blood.” He observed the colour change brought about by nitrite.  He wrote, “The addition of … nitrites to blood … causes the red colour to return…” Over the next 30 years, it would be discovered that it is indeed nitrites responsible for curing and not the nitrates added as saltpetre.  It was Polenski who first speculated that saltpetre is reduced to nitrite in the curing of meat in 1891 and in 1901 Haldane showed that nitrite is further reduced to nitric oxide (NO).  (Fathers of Modern Meat Curing)

Meat curing has been known to follow this exact pathway since 1901. The tantalising possibility, now presents itself that the preserving nature of the salt was recognised from things like the natural mummification in this exact region in China. The salt was applied to meat which had an amazing preserving impact as well as, what must have been, a mysterious reddening effect. To the ancients, it probably looked as if the meat was coming to life again. The Chinese alchemists in all likelihood gravitated to this as a possible key component of the elusive elixir of immortality. Finding such an elixir was the goal of Chinese alchemy. They probably applied its preserving power to all kinds of ailments and in a process of trial and error, a treatment for angina must have been especially effective.

Such experimentation takes many centuries and if this was a known cure and part of a medical prescription by CE 400 or CE 500, it means that curing of meat must have been very advanced in terms of it being practised in this region by this time.  From here, in terms of its key position on the Silk Road, the curing technology would have spread across Asia and into Europe.

Mummification – Key to Preservation Technology

The use of salt in embalming is an obvious application of the preserving power of salt to meat. It also seems reasonable to speculate that salt for preserving meat for domestic consumption came first and the application of the technology to mummification was probably a later development. One obvious reason for this is that meat preservation for consumption would have been a daily requirement. An immediate need, for a large group of people. So, many people, over a long time would have been engaged in experiments with various salts and ingredients to determine by a simple process of observation which salts ingredients and combination of factors preserved meat best. Burying the dead and mummification, on the other hand, was a far more infrequent event, with very few people working on solving the problem resulting in a much slower development trajectory. It is far more probable that techniques for meat preservation in general use would have been applied to the preservation of human bodies after death and in the art of mummification.

If one assumes this logic, it becomes an important tool to establish a date by which food preservation with salt was done by a society. The use of salt in embalming leaves us with clear records with precise dates and exactly what was used in meat preservation. If one assumes that meat preservation for general consumption would have predated the use for embalming, we can fix precise dates by what time a society used which salts to preserve meat.

I found support for this reasoning from Valerie Wohl. She writes, “While we do not know exactly how embalming began, it is likely that methods common at the time for preserving meat, fowl or fish probably suggested a clue for early techniques. One might bleed a fish, for example, then preserve it by salting, smoking, sun drying or otherwise heating it to prevent decomposition and store it for a later time. By the time of the very earliest documentation of the process of embalming (in about 500 BCE), it had become a sophisticated technique that had been evolved over hundreds of years.” (Wohl, V.)

The Chinchorro Mummies of the Atacama Desert

This line of reasoning yielded the most surprising results imaginable. Not in my wildest imagination did I think that the oldest mummies and their preservation would be linked, not with sodium chloride, but with what has been the curing salt of choice up until at least 1905, namely sodium nitrate. I have always thought, based on research on the subject, that sodium nitrate was used for preserving meat from the 1600s and reached its height in Europe in the 1700s and 1800s before it was replaced with sodium nitrite from around 1905 and in particular after World War 1. I thought it was used in isolated places around the world where various cultures re-discovered the reddening effect it had on meat, independently and over a long time and that this slowly filtered through to Europe where it gained popularity over time until it became a general practice. Never did I expect sodium nitrate to have been used for meat preservation since between 5000 and 7000 years BCE and not due to its reddening effect only, but especially for its preserving properties. Let’s look at this case.

It turns out that the oldest mummies on earth are the Chinchorro mummies from the Atacama Desert in Chile and Peru, dating from as early as 7000 BCE. (Guillén, S. E.; 2005) Gypsum, a sulphate mineral, was later used with clay (3000 – 1300 BCE), but mud and clay played an important role from as early as 5000 BCE.

The fascinating link between this region and sodium nitrate. Nowhere on earth are such large natural deposits of this salt found. The soil here is rich in sodium nitrate salt which is known as Chilean Saltpeter to distinguish it from potassium nitrate or regular saltpetre. A war was fought over these deposits and securing them was a major consideration of Germany going into World War 1. The second important factor is that the Atacama desert is the dryest place on earth. The soil is so rich in saltpetre and it is so dry that mummification occurred naturally, leaving mummies that exist since 7020 BCE.

Two of the most important ingredients in meat preservation namely heat/ drying and saltpetre were present in the mummification rituals of the Chicharro people of the Atacama Desert since as early as at least 5000 BCE. I do not think that it is too far a stretch to assume that these people knew about the meat-preserving ability of drying in combination with their special salts (sodium nitrate). Even though it is complete conjecture, I am comfortable to say that preserving meat through sodium nitrate salt and drying was probably known since at least 5000 BCE in Chile and parts of Peru. It is then not a stretch to say that this was likely to be known in the other two main regions in the world where saltpetre is found naturally namely in China and India. This is, of course, a fascinating possibility since this particular salt became the curing agent of choice in the 1700s which gave rise to the food category of cured meats and directly resulted in our use of sodium nitrite in meat curing today. This date of between 5000 and 7000 BCE is completely in line with a date proposed by Binkerd and Kolari.

Despite this tantalising possibility, the actual sodium nitrate concentrations at the burial sites in the Atacama Desert have never been studied. The degree of mummification varies tremendously (Aufderheide, A. C.; 2003: 141) which will indicate that various factors have been present in varying degrees.

The Tarim Mummies of China

A date of between 5000 and 7000 BCE is in line with a date proposed by Binkerd and Kolari. According to their iconic 1975 review article about the history and use of nitrates and nitrites in the curing of meat, “it appears that meat preservation was first practised in the saline deserts of Hither Asia and in coastal areas. Desert salts contained nitrates and borax as impurities. However, the reddening effect of nitrates was not mentioned until late Roman times.” (Binkerd, E. F. and Kolari O. E.; 1975: 655)  A probable time for this discovery is however not given.

I first thought that what they were talking about was salt preservation generally, but the more I look at events in the Atacama desert, the more I wondered if the particular preserving power of sodium and potassium nitrate was not known from the earliest times and the discovery, focusing on its preserving power and not on its reddening effect on cured meat.

A further elaboration of what Binkerd and Kolari may have been talking about comes to us from a 1977 newspaper article. According to it, the suspicion is that prehistoric nomadic hunters in Western Asia began carrying salt, containing nitrate with them to preserve the hunting catch. (The Indianapolis Star;  1977) The focus was indeed on nitrate and its preserving ability and not just on salt generally. I learned that nitrate deposits occur and precipitate as an efflorescent crust in amongst others the Egyptian and Namibian deserts, the Abu Dhabi sabkhas, and deserts of the Mojave, Death Valley and of course, the Atacama Desert and the Gobi Desert.  (Warren, J. K.;  2016: 1278)

It is, however, the largest desert in China, the Taklimakan Desert of Western China that offers the biggest surprise when I find the oldest examples of natural mummification in China, right in this desert region, replete with natural nitrate deposits. The conditions are almost identical to those of the Atacama desert.

Like the Atacama desert, the Taklimakan Desert is at the same time one of the aridest regions on earth and massive nitrate ore fields exist in the Turpan-Hami Basin, close in proximity to the Tarim Basin, in the Xinjiang province, where the oldest mummies in China was found. The nitrate deposits are so substantial, that an estimated 2.5 billion tons exist, comparable in scale to the Atacama Desert super-scale nitrate deposit in Chile. (Qin, Y., et al; 2012) The mummification happened, as was the case with the mummies of the Atacama Desert between 5000 BCE and 7020 BCE,  spontaneously.

The initial discovery was made in 1939 by the Swedish archaeologist Bergman Folke. A set of tombs were discovered in the Chinese province of Xinjiang, known as the Xiaohe Tombs. For 60 years the tombs were forgotten until in 2000 a researcher, head of the Xinjiang Cultural Relics and Archaeology Institute, found the tombs again. It wasn’t until 2005 that the excavations were complete. (www.ancient-origins.net)

The size of the area is unprecedented. So far there have been 330 tombs found in multiple different layers. The tombs include adults and children as well as 15 intact mummies. About half of the tombs were looted by grave robbers. It is the first time anywhere on Earth that so many mummies have been found.  (www.ancient-origins.net)

“Several bodies have been excavated from graves near Loulan, a site that once bordered a still shrinking lake fed by the Kongi River. Among these is the body of a young female with remarkably well-preserved facial features, whose radiocarbon date indicates that she died about 1200 BCE.” Subsequently, more than 500 tombs have been studied.  Dr Wang Bing Hua, director of the Ürümxi’s Archeological Research Institute, attributes the spontaneous mummification to three factors:  arid climate, salty soil and shallow, winter burial. Average salt content of the desert soil near Turpan is about 10g/ L but in the very surface layer, it can be five times greater. At Hami the soil contains layers of gypsum and at Cherchen actual salt blocks are obvious within the soil, especially near the surface.  Most burials are only about a meter below the surface.  (Aufderheide, A. C.; 2003: 268, 269) In the oldest cemetery so far discovered, the Small River Cemetery, mummies were discovered which carbon tests, done at Beijing University, show to be 3,980 years old. This takes the known date for meat preservation, by our logic of linking it with mummification, to almost 4000 years ago in China. The nitrate in Xinjiang Lop Nur exists in two forms: natural sodium nitrate mine and natural potassium nitrate. (en.cnki.com.cn)

The Turpan Basin is a “fault-bounded trough located around and south of the city-oasis of Turpan, in the Xinjiang Autonomous Region in far western China, about 150 kilometres (93 mi) south-east of the regional capital Ürümqi.” “The surrounding mountain ranges are the central Tian Shan in the west, the Bogda Shan in the north-west, the Haerlike Shan in the north-west, and the Jueluotage Shan in the south. Beyond the surrounding mountain ranges lie the Junggar Basin in the north and the Tarim Basin in the south.” (www.revolvy.com)

“Some geographers also use the term Turpan-Hami Basin, which is understood as including the Turpan Depression along with the Hami Depression (located to the east of the Turpan Depression, and to the southwest of the city of Hami) and the Liaodong Uplift separating the two depressions.” (www.revolvy.com)

One of these mummies may hold a further clue to their preservation. She became famous for her “excellent preservation and beauty and it is known as the Beauty of Xiaohe. It is a white person with round eyes, perfect eyelashes, and long hair and has features that are more similar to a European person than a Chinese person.” (www.ancient-origins.net)

According to Elizabeth Wayland Barber, her “beautiful eyelashes finally proves an earlier hypothesis, deduced from little detail at Zaghunluq, that those bodies that mummified had to have died in early winter, flash freezing and gradually freeze-drying over the next few months whereas other bodies decomposed.” She was dismayed at people’s acceptance or refutation of his arguments without dealing with the arguments posed.  In the Beauty of Xiaohe she, at last, had hard evidence. “Eyeballs, being wet, cause rapid decomposition of both themselves and the eyelash-holding eyelids when warm; but by the same token, being wet, cause rapid decomposition of both themselves and the eyelash-holding eyelids when warm, but by the same token, being wet, both they and the thin overlaying eyelids will freeze rapidly when being very cold, thus securing the eyelashes in place.  Unlike putrefaction, the gentle process of freeze-drying will not dislodge eyelids.” (Mair, V. H., Hickman, J.;  2014:  35)

It has been known from the earliest times that meat curing could be done only in the winter in the absence of refrigeration. If not, the putrefying and decomposing forces would overtake the preserving action of saltpetre and decomposition would be unstoppable. It is the combination of cold and dry conditions along with the use of sodium nitrate to preserve and ordinary salt (sodium chloride) to aid in drying out the meat, that forms a link between the earliest forms of mummification and modern meat-curing techniques. It seems unreasonable to think that the result of these forces, in combination, would have gone unnoticed. I further suspect that the power of these forces would have been practised in relation to fish, fowl, game and domesticated animals for centuries before they found inclusion in the earliest mummification practices.

The Silk Road

The location of the Turpan-Hami and Tarim Basins is very important. Crossing the Taklimakan Desert is possible at the foot of the mountains surrounding the Turpan-Hami Basin or along its streams such as the Tarim, “that spring from the mountains to enter the desert from its periphery but soon vanish into the sand. As ancient caravans from Eastern China approached Dunhuang at the edge of this segment of what eventually came to be part of the Silk Road to the Mediterranean, the near absence of water in the desert’s centre forced them to make a choice. The southern option skirts the desert along its southern edge at the foot of the steep Kunlun slopes descending from Tibet’s high plateau. Alternatively, the northern route passes through Hami and those communities living along the Kongi and Tarim rivers that lead to Loulan and Lop Nor.  It is along these routes that mummies from the Tarim Basin have been found.”  (Aufderheide, A. C.; 2003: 268, 269)

The caravans on the Silk Road approached Dunhuang, crossing vast sodium and potassium nitrate deposits. If the knowledge of its power was developed in this region and exported to Europe, I am sure that there should be remnants of this ancient knowledge in this city.

“One of the people who has extensively studied the Caucasian mummies of China, Professor Victor Mair of Pennsylvania University, said that he believes that early Europeans long ago spread out in different directions. He believes that some of these peoples travelled west to become the Celts in Britain and Ireland, others went north to become the Germanic tribes, and still, others journeyed east to find their way to Xinjiang. These ancient European settlers are believed to represent some of the earliest human inhabitants of the Tarim Basin, and Mair has stated that from around 1800BCE the earliest mummies to be found here are exclusively Caucasoid or Europoid rather than Chinese in origin.”

The origins of the mummies have been studied extensively using DNA technology.  Writing in the journals BMC Genetics and BMC Biology, Chunxiang Li, an ancient DNA specialist at Jilin University, and colleagues report on their analysis of human remains from the Xiaohe tomb complex also on the eastern edge of the basin.

They conclude that by reconstructing a possible route by which the Tarim Basin was populated, Li and colleagues conclude that “people bearing the south/west Asian components could have first married into pastoralist populations and reached North Xinjiang through the Kazakh steppe following the movement of pastoralist populations, then spread from North Xinjiang southward into the Tarim Basin across the Tianshan Mountains, and intermarried with the earlier inhabitants of the region, giving rise to the later, admixed Xiaohe community.” (Killgrove, K, 2015)

“The populations from the Russian steppe seem to have contributed more genetically to this population than did the populations from the oases of Bactria. “The groups reaching the Tarim Basin through the oasis route,” the researchers note, “may have interacted culturally with earlier populations from the steppe, with limited gene flow, resulting in a small genetic signal of the oasis agriculturalists in the Xiaohe community.””  (Killgrove, K, 2015)

A New York Times article on the origin of these people presents the picture clearly. It reads that “all the men who were analyzed had a Y chromosome that is now mostly found in Eastern Europe, Central Asia and Siberia, but rarely in China. The mitochondrial DNA, which passes down the female line, consisted of a lineage from Siberia and two that are common in Europe. Since both the Y chromosome and the mitochondrial DNA lineages are ancient, Dr Zhou and his team conclude the European and Siberian populations probably intermarried before entering the Tarim Basin some 4,000 years ago.” (Wade, N; 210)

It is however not the origin of these people that interest me as much as their destination and the destination of the traders who passed through this region. The Silk Road that ran through this region reached into the heart of the Middle East and Europe to the West and into the rest of China and India to the East. There is an interesting possibility that comes up and that is if it is possible that the Europeans brought the technology with them. Of course, this is a possibility but then there is the matter of the unique level of sophisticated insight into saltpetre from this exact region. Such a level of understanding of saltpetre did not exist in Europe for many centuries. It seems more likely that the transfer of technology went from Tarim, East, into Europe, rather than the other way round. The next section explains what I mean by this.

Dunhuang

The question is if there is any evidence that anything was done with the nitrate deposits and clear evidence of its preserving power in the mummification. If this was the region where curing of meat progressed into the art that we know it today, is there any evidence of this? Any ancient document or reference, not just from China generally, but linked to this region. These were the actual questions I asked myself as I was searching. This is not a device I employ after the fact for the sake of creating drama.

I knew my general geographic area of focus was the one I show below featuring the Tarim Basin.

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I started plotting the important points.

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Looking at the images above, the saltpetre deposits are the largest at Yuli, marked as NO3. Loulan is the city where many of the mummies have been found. Dunhuang is a major city before the trip past or across the desert was undertaken on the Silk Road past the Tarim Basin.

I did a search for any reference to saltpetre from the city of Dunhuang which would have been a key trading city in the area and important in terms of its location on the Silk Road. Not in my wildest imagination did I expect to uncover what I found!

It is here, in the Mogao Caves, where the medical text was discovered that we referred to earlier.

The possibility that the art of meat curing was developed in Turpan and spread around the world is most promising. Despite this not being my main point under discussion here, it is important to note that Europe may also have influenced the community around Turpan. Influences certainly did not only go one way.

A fascinating link has been discovered between the mummies in Turfan and the Austrian city of Salzburg. Victor Mair, a professor of Chinese in the Department of Asian and Middle Eastern Studies at the University of Pennsylvania was committed to tracing the ancestry of the mummies. “In Xinjiang, a Chinese colleague had slipped him a . . . gift: a swatch of blue, brown, and white cloth taken from a twelfth-century-bc mummy. The fabric looked like a piece of Celtic plaid. Mair passed it over to Irene Good, a textile expert at the University of Pennsylvania Museum. Good examined it under an electron microscope. The style of weave, known as a “two over two” diagonal twill, bore little resemblance to anything woven by Asian weavers of the day. (Indeed, it would be almost another two millennia before women in central China turned out twill cloth on their looms.) But the weave exactly matched cloth found with the bodies of thirteenth-century-BCE salt miners in Austria. Like the DNA samples, the mysterious plaid pointed straight towards a European homeland.” (Tocharians: The Whites of Ancient China)

This startled me. The thread that ties it all together is salt and meat curing. Is it possible that a mummy found in the region which I believe may have been pivotal in spreading nitrate curing of meat across the world may have some direct or indirect link with the Austrian salt mines? It unlocks the possibility that work done on the use of nitrate salts was influenced by work done in Austria.

In my mind, the fact that nitrate and nitrite did not only have negative effects on human health was discovered by contemplating the possible location where the art of meat curing with nitrate originated. Today students learn this from textbooks but I somehow like the journey of discovery that I took much more.

Vilifying Nitrite: A Drama for Fools

After telling the story of my own discovery that nitrate, nitrite and nitric oxide are far from evil molecules and not tantamount to poison being added to meat, I return to a key subject. Is bacon safe to consume? Is the use of nitrate and nitrite in meat curing irresponsible? What about the claims that it causes cancer?

There is no greater illustration of willing enslavement to an incomplete understanding of nature than the drama related to the use of nitrites in meat processing. Humans happened upon a natural phenomenon that special salts containing nitrate change the colour of meat and have the power to preserve it. Since the start of the use of nitrites in meat curing, it was viewed with great suspicion due to its inherent toxicity. Much of Bacon & the Art of Living is dedicated to chronicling the unfolding of the great saga of nitrate and nitrite and the discovery of its essential nature and role in meat curing. There is no need to repeat any of what has been written earlier in this work.

The use of a substance that is, in high concentrations, poisonous is, after all, nothing new to humans. Alcohol is one of the best examples. Aspirin is another example where, in high dosages, it is dangerous despite its positive benefits at low dosages. Ultra-high dosages of ascorbic acid are equally likely to have adverse effects and cause diarrhoea and nausea. Vinegar is another good example which in moderation is beneficial but consuming too much over a long period of time will have serious detrimental health implications. There are hundreds of other examples we can give. I heard of a well-known speaker in the UK who addressed a group of meat processing professionals and started his talk by accusing them of poisoning the public through the use of nitrites. Statements like this show a serious lack of understanding of not just nitrites but almost every other food ingredient customarily used in food production.

A far more serious issue was discovered in the late 60s and early 70s related to the formation of n-nitrosamines. Nitrosamines are cancer-causing. We have already dealt with the matter in great detail in Chapter 15.06: Regulations of Nitrate and Nitrite post-1920’s: the problem of residual nitrite where we outlined the scientific, industry and government response to the issue.

A friend of mine who is a 3rd generation German Master Butcher tells the story of his grandfather who used to buy nitrites from the pharmacy in the early days and made the most beautiful rich pink bacon. There were no limits on ingoing nitrites in those days and the role of ascorbate was poorly understood and, sadly he passed away from colon cancer. This anecdotal account has been subsequently confirmed by countless studies and indeed it is true that at the wrong concentrations, without the use of ascorbate or erythorbate, the high nitrite levels used in curing meat are tantamount to poisoning the consumers. The chapter I just mentioned deals with the international response to the subject and the combined legislative framework for the use of nitrites in food. The minuscule amounts of nitrites used in bacon curing today along with the use of ascorbate render bacon a safe product to consume in moderation. Of course, the caveat should always be remembered that this should be done in moderation as is the case with any other processed food, red meat, beer, cheese, milk, alcohol, dried milk powder, etc.

What has been said before should settle the issue, but over the years a number of other factors occurred to me which must be added to the discussion to un-vilify nitrite.

Concluding

Concluding an experience this monumental is not a simple one-chapter endeavour. In the next section, we cast our gaze across the matter of nitrosamines, the reaction of nitrites in the stomach and we touch on the physiological importance of nitrite.


(c) Eben van Tonder


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References

Herrmann, S. S., Duedahl-Olesen, L., Christensen, T., Olesen, P.T., Granby, K.. 2015. Dietary exposure to volatile and non-volatile N-nitrosamines from processed meat products in Denmark. Food and Chemical Toxicology, Volume 80,
2015, Pages 137-143, ISSN 0278-6915, https://doi.org/10.1016/j.fct.2015.03.008. (https://www.sciencedirect.com/science/article/pii/S0278691515000873)

Hotchkiss, J. H.. 1984. Sources of N-Nitrosamines Contamination in Foods. Adv Exp Med Biol. 1984;177:287-98. doi: 10.1007/978-1-4684-4790-3_14.

Scanlan, R. A.. 2003. Nitrosamines. Encyclopedia of Food Sciences and Nutrition (Second Edition).

Petersson, J.. (2008) Nitrate, Nitrite and Nitric Oxide in Gastric Mucosal Defense. Digital Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 328. Uppsala Universitet. SSN 1651-6206; ISBN 978-91-554-7152-1; urn:nbn:se:uu:diva-8624

Uddin, R., Thakur, M.U., Uddin, M.Z. et al. Study of nitrate levels in fruits and vegetables to assess the potential health risks in BangladeshSci Rep 11, 4704 (2021). https://doi.org/10.1038/s41598-021-84032-z