There are many reasons to explore the relationship between cocoa and nickel. In this field, the changes that advances in science and research make it possible to perceive are being addressed; our understanding of nickel, too, continues to grow and evolve.
Many people are still convinced that some foods are "naturally bad". The innovations of modern immunology have instead helped us understand that no food is "against" us and that it is only the bad use we make of it that can turn it into an occasion for harm rather than nourishment.
I have already written about this in an article on LifeGate, yet there are other reasons too that prompt a deeper exploration of the relationship between cocoa and nickel.
Cocoa is often regarded as a potential enemy because of its nickel content, but today the very function of nickel in foods and its possible role in human health have changed radically, and it is certain that reactivity to a food containing nickel also depends on many other factors. To name but a few: the presence of other heavy metals in the growing soil and in the food itself, the way in which it was cultivated, and the presence of certain types of fats in the composition of the chocolate.
Today, then, even chocolate can make its peace with nickel, thanks to new research that has helped to clarify the role of nickel in human health and the reasons behind the reactions it sometimes triggers.
Nickel in itself is a mineral naturally present in the body (every haemoglobin molecule contains a small amount of it), and its presence in foods can be beneficial (for example for people with anaemia problems) or can also cause discomfort in certain cases of contact dermatitis or in cases of dyshidrosis. It has also been understood that in many cases the consumption of foods containing nickel (such as tomatoes and spinach) triggers systemic and widespread reactions on the skin and throughout the body, generating those symptoms classified as SNAS, or Systemic Nickel Allergy Syndrome. So much for the bad news, because clinical experience has made it possible to recognise that although hazelnuts, almonds and tomatoes contain a great deal of nickel, their use becomes possible without harm as soon as a person begins to detoxify from it. A truly important piece of good news.
A distinction must therefore be drawn between the presence of nickel in a food and its possible effects, which can depend on many other factors. The nickel content of a food (whether spinach, pear, cocoa or tomato) depends on the botanical characteristics of that specific plant, and the presence of nickel salts in the pollen that preceded the development of those fruits has a documented and intense natural antiparasitic action — as if the plant were able to defend itself against parasites or harmful insects through the concentration of nickel in the fruit, drawing it from the soil in which it grew (in the article Allergia al nichel: alimenti consentiti e alternative a detailed breakdown of foods with a high content of this salt can be found).
The response to nickel is always individual, which highlights that it depends on other elements beyond merely the specific nickel content of a food.
A food is therefore not harmful "because it contains nickel", as many claim, but because it contains "individually too much" of it, and often because it is associated with other substances that facilitate the body's reactivity towards it.
This explains why, at the start of a nickel rebalancing diet, the consumption of oats and maize (high content) is not permitted, whereas wheat (medium-low content) is, even though individually one may come to understand after a few days that wheat too needs to be monitored — or, conversely, that maize can perhaps be allowed as well.
A very recent study, published in the Journal of Allergy and Clinical Immunology, concerning reactivity to certain nickel-containing substances such as almonds, concluded by identifying as responsible for the reaction not so much the almond itself, but the fact that it had been roasted during preparation, with the formation of different substances — such as those generated by the Maillard reaction, which colours the surfaces of certain foods (as happens with roasted oilseeds) and which amplify the production of antibodies against the food itself. A dried almond may cause no discomfort (despite the nickel it contains), but its "roasted" preparation can lead to a very intense reaction to that food (Chinthrajah RS et al, J Allergy Clin Immunol. 2016 Apr;137(4):984-97. doi: 10.1016/j.jaci.2016.02.004).
This further development also comes from recent immunological studies that have established that the allergic reaction to the Brazil nut occurs only when certain particular fats are present alongside the nut's protein (Mirotti L et al, Allergy. 2013 Jan;68(1):74-83. doi: 10.1111/all.12057. Epub 2012 Nov 9). The Brazilian research group verified that both the sensitisation reaction and the allergic reaction occur only when certain particular fats are present alongside the Brazil nut protein — fats that in a sense enable the reaction — and published their work in Allergy very recently. It was a discovery of considerable value because it broke the reactivity criteria established over many years. An allergy depends not only on the reaction between, say, cocoa and the immune system, but also on the environment and the type of fat accompanying this recognition. In plain terms, the type of fat used in the preparation of a particular chocolate, for example, may be the true cause of the reaction that develops towards it, regardless of the high or low nickel content of the cocoa itself.
For many years, all Westernised populations — and Italians in particular — lived on biscuits, crackers and snack cakes in which hydrogenated vegetable fats (margarines and trans fatty acids) were always present, containing abundant nickel in their composition due to the use of nickel in the catalysis of fats that enabled their hydrogenation and production.
Today this situation is slowly and gradually declining (many manufacturers are ceasing to use hydrogenated fats in industrial preparations), but the "conditioned" association that lasted for years and was memorised by the immune system could for a long time yet continue to trigger reactions to industrially cooked fats. This is one of the reasons why, when a nickel reaction is identified using Recaller and BioMarkers tests, patients are also asked to check all industrial baked goods in which fats were used during preparation.
Yet something is changing, because direct clinical experience with certain nickel-rich foods such as walnuts, almonds and hazelnuts obliges those sensitive to nickel — at least in the initial phase — to monitor their intake, while gradually allowing the reintroduction of increasing quantities that cause no discomfort.
In the majority of cases this occurs, and it applies also to foods such as tomatoes, spinach and cocoa — products of the earth from which it is possible to derive benefits in many ways.
In recent years, through direct clinical practice, it has been coming to light that when the body reacts to the nickel contained in a food, this depends on contact with heavy metals of other types as well. In practice, the nickel contained in a fruit reacts far more strongly in the body if it is accompanied by other heavy metals such as cadmium or chromium, which are indicators of possible soil contamination or of excessive exploitation of the soil with chemical fertilisers. Ethical and responsible cultivation can therefore be the starting point for supplying cocoa that naturally contains nickel but does not contain cadmium, chromium and arsenic as residues of environmental contamination. In that case, even the nickel present — which is lower than expected — may cause no discomfort. Not even for sensitive individuals.
Furthermore, a 2015 study examined differences between traditional dry cocoa cultivation and intensive cultivation with irrigation, which can result in a nickel content in the final product that is up to twice as high. Choosing to grow cocoa in a way that respects the environment and the plant changes its nickel content and the possibilities for its use.
The response to nickel remains and will always remain individual, but it will always be lower if foods in general, and cocoa in particular, retain their polyphenol and antioxidant content — which helps control inflammation — if the blending fats are wholesome, and if cultivation meets certain criteria.
Not only does it now appear that nickel could also be "good", but it is finally clear that its reactivity depends on the specific characteristics of the cocoa and on the way it is grown and prepared for end use.
After years of exposure to the combination of hydrogenated vegetable fats and nickel, human organisms remain "conditioned" by habit and are immunologically suspicious of anything that resembles the old products containing hydrogenated vegetable fats.
When a new production culture — or the ability to eat well by choosing quality — becomes more widespread, and it becomes socially evident that taking proper care of chocolate makes it different from the old kind made with potentially contaminated fats, nickel will once again become acceptable, whereas poor fat quality will not.
The points to take into account for a revolution of this kind are therefore, in light of the most recent immunological advances, as follows.
This will also lead to a lower quantity of nickel in foods, but that nickel will have an ever-decreasing likelihood of triggering a reaction in sensitive individuals, resulting in a greatly reduced clinical reactivity, similar to that seen with organic nuts and almonds.
In this field, the changes that advances in science and research make it possible to perceive are being addressed; our understanding of nickel, too, continues to grow and evolve thanks to the development of knowledge, and we are glad witnesses and participants in that process.