Edible insects and chitin: all you need to know about bugs

Why we talk about edible insects

I wrote this article after several requests received from friends and followers of the blog; indeed (the interest of media is enormous, with the inevitable stances: those in favor (few in fact), those who are definitely making a real war against it.
Deferring my position to later, in the Conclusions section, I would like to address with extreme objectivity what now seems to have become a thorny topic, more and more red-hot every day.

But first it is important to answer the first question: why so much pressure to introduce insects into our diet?

Simple and short answer

To replace or supplement the incessant demand for animal protein, meat above all, with the aim of saving the world and facing the food shortages.

More elaborated answer

Most likely by 2050 the world population will reach 9 billion. Already today, the pace of food production is unsustainable; taking into account the impossibility of separating human well-being from the well-being of the earth.
Moreover, we have problems of droughts and the rise in the average temperatures, factors that adversely affect agriculture pointing to a very likely famine for our future.
Deforestation to create arable land is no longer an option.

In light of the above, in order to maintain our food opulence, viable alternatives are being considered; and edible insects are among them: they can provide an equivalent amount of protein to cattle, pigs and poultry; they require less land and water and produce much lower levels of greenhouse gases.
We can start.

Is eating insects new?

In all likelihood, mankind owes its existence to edible insects! When primordial man knew neither how to hunt, nor how to cultivate, not to mention how to breed, the only resource of sustenance was insects, along with fruit and berries.
After that, the developed skills, favorable climates, together with the abundance of water, typical of our latitudes, enabled agriculture, breeding and thus new types of food (basically the ones we know now).
But the ‘old food resources’ have not been completely abandoned and still continue to feed, albeit in smaller percentages, millions of people over several countries (a total of 113: mostly Thailand, the Philippines, Mexico, Cambodia, China and several African countries); geographical areas where the hot and humid climate and the social economy do not always allow easy access to other sources of protein.
Let it be clear, however, that insects are not only eaten because of necessity!
For many peoples (and to be honest, even those who taste them for the first time often agree) edible insects are delicacies… and certainly their digestive capacity is also markedly different, compared to those who start introducing them into their food choices.

So are insects really edible?

More than 1 million insect species have been discovered worldwide (experts assume there are at least ten million), yet only about 1900 fall into the edible category: this is because although insects are rich in protein and healthy fats, not all of them can become food, due to the toxic bio molecules they contain.
Returning to the 1900 specimens, only 3 (the house cricket, the meal worm and European migratory locust) have recently received EFSA approval, with another 9 on the waiting list.
Hence the discussion about edible insects and chitin with the other bio molecules present immediately began.
If you frequent social media, you will certainly have come across posts about the danger of this Novel Food, which we have seen so much novelty not to be.
Although I personally belong to those who have an insurmountable wall about seeing them as food, I can’t help but feel enthusiastic about learning about them; more like having a clear idea and not hearsay. Also because, let’s hope never, but if time really was a circle and mankind’s existence again depended on edible insects, along with berries and fruit, I would honestly want to know all the pros and cons.

But is it true that we already eat insects without knowing it?

Yes it is true, particularly in the form of additives.
Carmine for example is a bright red dye derived from the desiccated bodies of insects, of the Cochineal or Polish cochineal type.
It is a dye used in many products, from cheese to paints; people are hardly aware of its use, due to the fact that labelling laws usually do not require its disclosure; something that has clearly attracted the attention of some communities, vegetarian above all.
Suffice it to say that in several countries around the world, manufacturers can simply adopt the label ‘added colour‘.
The dye is also listed as crimson lake or natural red number four; in the EU it is identified as additive E120.
At other times, you might come across a more sincere label, where it reads ‘carmine’ or ‘cochineal dye’.
Oh, and don’t forget the next time you adorn yourself with a red lipstick: you are most likely smearing some cochineal on your lips!

E904, on the other hand, is an additive and polishing agent for pills and candies.
Basically, Shellac, an organic resin secreted by a small insect, Tachardia lacca, also from the mealybug family: we are talking about the relatives of aphids.

What is chitin

Chitin is the second most abundant polymer that exists in nature (after cellulose) and constitutes the largest percentage of carbohydrates in edible insects in the form of polysaccharides; but it is also found widely in mushrooms (around 7% in Agaricus Bisporus or champignons).
But also in the eggs of worms of the nematode family: parasites of plants and animals, including man.
And, last but not least, in other members of the arthropod family such as crustaceans (in the shells of shrimps 20%).
Chitin (and its derivative chitosan) is the building material of the outer skeleton (the exoskeleton); it serves to protect the animal that wears it, like a ‘Robocop-style shield’ in other words; and an edible insect contains about 2.7-49.8 mg/kg of it.

Edible insects and chitin as a health hazard

The problem is that in addition to its mechanical action to protect the producer, it also has an immunogenic property, i.e. it can stimulate the immune system to act, producing antibodies against it.
In practice, it acts like a threat to those who ingest it, despite being a non-toxic, biodegradable and bio-compatible polymer; characteristics that have in fact been exploited for several years now in the fields of health, drug administration, agriculture, gene therapy, food technology, nanotechnology and bio-energy[1].

As mentioned earlier, exogenous chitins and chitinases can in some cases provoke innate immunity in humans, causing a kind of inflammatory cytokine storm capable of damaging organs (leading to asthma, atopic dermatitis, etc.); and in the case of persistence, even death, through serious diseases such as multiple sclerosis, cancer or systemic lupus erythromatosus (SLE), et similia[2].

But some say that chitin is good for you!

In spite of what was said in the previous chapter, we have more than one specific piece of research, carried out directly with humans, that refutes its dangerousness.
For example, in a study involving 20 North Americans (i.e. not regular consumers), it was found that the daily ingestion of 25g of cricket meal, for 14 days, not only did not harm the subjects at all, but they also achieved a probiotic improvement in their intestinal microbiome[3].

So who is right? Let’s see what science says

Let’s start with a certainty: ingested chitin can only be eradicated through the specific enzyme capable of destroying it, chitinase.
And therein lies the problem: humans do not have this specific enzyme.
Hence the viral post that is circulating on the web at the speed of light; the web which, as we know, is indeed an infinite and invaluable resource, but which at the same time can generate monsters, given the superficiality with which technical information, lacking in feedback and sometimes in substantiation, is spread.

What the Meme says: “it basically states that given the inability to digest chitin due to the lack of chitinase, we risk various health problems, even serious ones such as cancer”.

Unfortunately, nothing in science is clear-cut and with only one universally valid answer: in fact, both the position of the pro and con supporters is only true up to a certain point; just take a look at what has been published so far in the scientific environment, and you will get ideas… even more confused than before!

– a large group of researchers claim that although the human body does not synthesize chitinase, it does contain chitinase-like proteins or enzymes with chitinolytic activity; however, the digestive efficiency of chitin depends on the individual: this is due to the fact that we lost the need to digest chitin a long time ago [4,5].

– as previously mentioned, some scientists state that not being able to destroy chitin can be a real problem; as this substance is immunogenic, it can bind to specific proteins causing a storm of cytokines, which cause inflammation, autoimmune diseases, various allergies and more[2]; but in the same paper, there is no denying the fact that chitin has incredible characteristics to offer cures for diseases that are difficult to treat;

– some others argue that not possessing chitinase is not a real problem: the undigested chitin can leave the body via the faeces without interacting with metabolic activities;

– others claim that just as with cellulose and other fibers, for which we do not possess the endogenous enzymes, we could rely on the micro-organisms in our intestinal flora, which produce chitinase[6,7];

– and again, for another group of researchers, the danger of chitin depends on its size:
(a) intermediate pieces (40-70µm) are dangerous to health as they can generate inflammation;
b) the small ones <40µm as well as not being dangerous, even possess anti-inflammatory properties, capable of activating leukin-10
c) finally, the large ones >70µm are inert, thus completely irrelevant to metabolic activities[8].

Well? Doubts upon doubts

So, are we able to digest chitin or not?
If yes, is it good for us or not?
Is there a maximum permissible level for chitin?
Which is the dimension of the chitin that our body tried to digest?
Or, if we started consuming insects today, when could we have a suitable profile of chitinase-like enzymes?

My perplexity is shared by almost all scientific papers, where they conclude with lapidary phrases such as: ‘More in-depth analyzes are needed‘; or ‘The understanding of the relationship between chitin and immune responses is not yet fully completed‘[9]; or ‘More rigorous and better controlled human intervention studies are needed to confirm the health benefits and better assess the risks associated with entomophagy‘[10].

To date, I believe no honest scientist will ever be able to explicitly and clearly satisfy these doubts; both because rodent research often does not adequately represent human responses, and because science lacks clinical studies conducted on thousands of individuals and of long duration[3].

Yet…

Of course, the possible risk of chitin could be eliminated by preferring the larvae, as opposed to the formed insect, since they contain much less of it; but as they are no longer ‘crispy’ at that point, they would probably be less inviting to the palate.
Or one could remove the fins and legs (locusts in the first place), in order to reduce the chitin, as is done with shrimps; but it would be a rather complicated job at the industrial level at the moment, and certainly in insect-based flours, the industrial process does not usually involve removing the chitin-rich parts.
Moreover, we should always bear in mind that it is the dose that makes the poison: if we do not consume edible insects seven days a week, twice a day, the presence of chitin in body would perhaps be the least of our problems.

The benefits of edible insects

Science, industry and the investment world are slowly discovering the enormous economic potential of edible insects. Certainly not only for their taste, there are many reasons to consider incorporating them into your diet… I mean that for you!

– Edible insects are a good alternative to meat due to their protein content, which varies from 20% to 76%, depending on the species, life stage and diet of the insect itself;

– In addition to being a good source of protein, and therefore a valuable food for humans and a profitable type of feed for animals, edible insects also have a bright future in the world of biomedicine, due to the presence of various functional substances (just to name a few: antimicrobial peptides, a variety of amino acids, functional lipids, vitamins, hormones such as interferon, steroid material, active polysaccharides, trace elements, chitin/chitosan, lecithin, etc.); which can be useful in the treatment of certain ailments, even serious ones, unfortunately common to many people: immunodeficiency, gastrointestinal disorders, fatigue, cancer, high blood sugar and blood pressure, insomnia and much more)[11].

Read the warnings carefully

In EFSA’s 2015 report on the risks of edible insects, it states that the possible risks depend on how they have been bred and how they have been processed (after all, nothing different from animals for human consumption).

So insects caught in the wild are better?
Contrary to what one might think, non-farmed insects require more caution: being more refractory than humans to the absorption of heavy metals potentially present in their environment (pesticides and other industrial substances), they could cause poisoning.
It follows that those interested should only buy edible insects bred for human consumption and in certified establishments.

In any case, insects defined as edible can still create allergic symptoms, some very serious. Considering that some (flour moths, crickets and locusts) belong to the family of crustaceans allergies to the latter (shrimps, lobsters, etc.) are usually replicated for terrestrial insects as well; and the risk does not disappear with cooking[12].

Conclusions

In the end, as has emerged throughout the article, contradictions reign supreme on the issue.
At this point, some general considerations need to be made in order to better understand the scope of the problem.
First of all, let us try to drop the veil of hypocrisy.
Insects are disgusting. But at the same time, I tend not to eat crustaceans for ethical reasons: prawns, lobsters (never!), shrimp and every ‘delicacy’ well known to westerners… you must have understood by now that we are talking about the same things!
Yes, the family is the same and the famous chitin as well.
The living proof is my mother (in good company with many others) who experiments the so-called yuke factor towards whole crustaceans; she just can’t see all those little legs and antennae; but if you put only the contents in front of her, then she can’t help but like the taste.
In short, what we disgust, on the other side of the world is considered a delicacy; and vice versa.

So should we make it a question of hazard or of customs and culture?

Understand for yourself that if we do not take issue with chitin while eating shellfish (or mushrooms: I am a big consumer of them), the battle takes on the contours of intellectual dishonesty. But we would totally agree instead if we confined ourselves to the cultural issue.
And then, let’s face it, many of us have (or had) a very big number of friends or parents fighting with cancer, chronic inflammation or autoimmune diseases, but how many of them were eating insects?
This is to say that not even the foods on which the average person bases his or her diet are ‘all that good’: in 2018, well over 18 million new cases of cancer were observed worldwide (many of these, it is likely, without ever having ingested a single edible insect, with or without chitin) and the figures are set to rise.
This is why edible insects and the chitin they contain, from my point of view, occupy an entirely relative position on the list of concerns; on the contrary, I am more concerned about microplastics or glyphosate residues in the fish, chicken and meat we eat every day of the week!
Purifying the air, water and food from these pollutants does not seem to be possible to date.
What is more, the body has no innate or adaptive immune response to these new substances: we find ourselves in total danger with no way to defend ourselves.

Having resolved, the chitin aspect, we come to the crux of the matter.
Given the laudable goal mentioned at the beginning, i.e. the search for alternatives to animal protein, would it not be better to ask ourselves why we have reached the point of considering insects as food?
Science is making great strides, but not so much as to find immediate and painless solutions to restore the planet’s well-being.

So what to do? Like a broken record I have been repeating for three years: reducing our food consumption, reviewing the basics of nutrition by eliminating or reducing meat and animal products, would already be the first steps on the path to recovery!
As I explain well in this in-depth study, intensive livestock farms are among the first causes of pollution at 360 degrees; and as I said before, precisely because we want to satisfy the enormous demand for animal proteins, the quality of food we ingest is close to zero; with irreparable damage to human health, by now I would say quite evident and under everyone’s eyes.

Unfortunately, we humans are not exactly endowed with foresight and do not like to change our habits, even if we have it all figured out in theory; it is probably a form of addiction or cognitive dissonance, I don’t know; the fact is that it is easier to wage war against a specific enemy (today, insects) than against our own lifestyle.
We just can’t take it, we don’t accept it, it’s too big a burden; so better witches to hunt.
And likewise, the masters of steam see nothing better to do than to continue to produce alternatives, even disgusting ones, it doesn’t matter, in order to maintain the ravenousness of this pampered child, called human being, apparently impossible to educate, but only to pander to: the perfect customer, an endless phagocyte.
When it would be more constructive and truly praiseworthy, to invest on culture; through massive information campaigns on proper nutrition, already starting in schools; instead, none of this happens.

In conclusion, dear friends, let us care for our future and that of the generations to come; but let us do it for real and in a comprehensive manner towards all threats; this requires a major change, starting with our lifestyle, which is not so difficult after all; let us stop overproducing and over-consuming everything; let us learn to eat less, but better and with higher quality; in this way, I am sure, we will have no need to resort to insects or other, even artificial, animal protein substitutes.
I know it is a harsh and sometimes annoying speech, but it had to be done: after all, that is what CHE is for!

Good thoughts and good revolution to all

Bibliography
1) Khoushab, F. & Yamabhai, M. Chitin Research Revisited. Mar. Drugs 8, 1988–2012. 2010
2) Patel, Seema, and Arun Goyal. “Chitin and chitinase: Role in pathogenicity, allergenicity and health.” International journal of biological macromolecules vol. 97 (2017): 331-338.
3) Stull, V.J., Finer, E., Bergmans, R.S. et al. Impact of Edible Cricket Consumption on Gut Microbiota in Healthy Adults, a Double-blind, Randomized Crossover Trial. Sci Rep 8, 10762 (2018).
4) Tavanti, Arianna Vega, Karina Kalkum, Markus 2012. Chitin, Chitinase Responses, and Invasive Fungal Infections – International Journal of Microbiology
5) Paoletti, Maurizio G., et al. “Human gastric juice contains chitinase that can degrade chitin.” Annals of Nutrition and Metabolism 51.3 (2007): 244-251)
6) Adrangi, Sina, and Mohammad Ali Faramarzi. “From bacteria to human: a journey into the world of chitinases.” Biotechnology advances 31.8 (2013): 1786-1795.
7) Dohnálek, Jan, et al. “Chitinase Chit62J4 Essential for Chitin Processing by Human Microbiome Bacterium Clostridium paraputrificum J4.” Molecules 26.19 (2021): 5978
8) Lee, C.G.; Da Silva, C.A.; Cruz, C.S.D.; Ahangari, F.; Ma, B.; Kang, M.J.; He, C.H.; Takyar, S.; Elias, J.A. Role of chitin and chitinase/chitinase-like proteins in inflammation, tissue remodeling, and injury. Annu. Rev. Physiol. 2011, 73, 479–501.
9) Elieh-Ali-Komi, Daniel & Sharma, Lokesh & Dela Cruz, Charles. (2018). Chitin and Its Effects on Inflammatory and Immune Responses. Clinical Reviews in Allergy & Immunology.
10) Stull, V. J. “Impacts of insect consumption on human health.” Journal of Insects as Food and Feed 7.5 (2021): 695-713.
11) Qian, L., Deng, P., Chen, F. et al. The exploration and utilization of functional substances in edible insects: a review. Food Prod Process and Nutr 4, 11 (2022).
12) van Broekhoven, Sarah et al. “Influence of processing and in vitro digestion on the allergic cross-reactivity of three mealworm species.” Food chemistry vol. 196 (2016): 1075-83.

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