Not all that glitters is gold. We often ignore what we don't see, but that doesn't mean it can't harm our health or the environment. It is the case of titanium dioxide, indicated (not always) on food labels as E171, a well-known additive used in cosmetics, drugs and even food, often produced in nanometric form.
From salt to sweets to milk. Nanoparticles are now everywhere. These are aggregates of atoms and molecules, so small that they are not visible to the human eye: 50 times smaller than a hair. And even if we don't see them, it doesn't mean that they are harmless, let alone that they can be ignored.
However, titanium dioxide isn't the only nano chemical considered a risk by researchers. There are also gold, silver, zinc, cerium dioxide and silicon dioxide and many others still, whose effects on man and the environment are still incomplete and the subject of numerous studies and scientific evaluations.
Food is "nanofood" when during its cultivation, production, processing or packaging we make use of the so-called nanotechnology, the science that designs and creates nanostructures. Of these there are several, by function, shape or composition but all have at least one dimension smaller than 100 nanometers, where a nanometer is equal to one millionth of a millimeter.
But if the effects are still unknown, why are they used so much in the food industry? If you reduce a solid into a nanomaterial, its surface area increases, so as to be able to drastically reduce the quantity used, with the advantage of a better exploitation of its properties. In the food sector it means reducing coloring and flavoring additives and are used to make sauces more fluid, whiten creams, make some products more crunchy or powdered preparations less granular, but also to lengthen the expiry date of ready-to-eat foods.
The questions around this topic are innumerable: can nanotechnologies improve the preservation of foods, improve them or even lengthen their shelf life? Are there any risks for consumers? And how do they interact with the cells of our intestines?
Even if they have been approved by passing safety studies, nanoparticles have different and often very unpredictable chemical-physical properties, having a exposed surface which exponentially increases their chemical and biological reactivity.
Some studies have focused on the gastrointestinal tract, i.e. the mouth, esophagus, stomach and intestines, while others show how nanoparticles, once swallowed, can also reach the liver, kidneys, lungs, brain and spleen through the bloodstream.
On the one hand there is the risk that they enter the bloodstream, causing still unpredictable consequences. On the other hand, they can come into contact with DNA. Then there is the risk of plastic nanoparticles, which are formed from the disintegration of plastic waste that pollutes our seas, then coming into contact with the fish and shellfish we serve at the table. Here, too, the effects are still unclear.
Based on the study, however, conducted by Maria Grazia Ammendolia and Francesco Cubadda of theIstituto Superiore di Sanità and published in Food and Chemical Toxicology, one can hypothesize a modulating effect on the endocrine system, in simple terms, they could have an effect on the production of hormones.
The study is based on the effect of titanium dioxide nanoparticles on the intestinal cells of rats. What emerged is surprising: it was rediscovered in male rats an increase in testosterone, even if carried out for a few days and with a low dosage.
However, however according to Cubadda these effects are not typical of all nanomaterials, therefore one cannot make a lump of grass, but must be evaluated on a case-by-case basis. According to European legislation, if nanoparticles are present in a product, in addition to having to be declared on the label, it must also be previously evaluated by theEFSA, the European Food Safety Authority.
And if they are considered a health risk, EFSA will ban their use. In any case, the consumer must be informed about what he is eating, however, as very often happens, the presence of these nanoparticles is not even mentioned on the label, as has also been demonstrated by a denunciation of the latest issue of the Swiss magazine Bon a Savoir. Based on the results of a laboratory analysis that had sampled 15 products, it emerged that all the samples reported the presence of these nanoparticles, although no one declared them. Thanks to these results, starting next May 2021, food producers will be obliged to mention its possible presence.
All these studies have sounded an alarm about the possible negative effects that these nanoparticles can have. Precisely for this reason, the EU, in addition to regulating its use in food products, is also committed to promoting and funding research to establish the possible effects, even if it is difficult to keep up with the technological development of the sector. The underlying problem, however, is that in most cases, these particles they are not water soluble: once absorbed by the human body they can accumulate inside the tissues.
A long debate that has not yet found an answer. Given the uncertainty on the subject, there is no international regulation with reference to nanoproducts or their underlying nanotechnologies. Self the French government has banned the placing on the market of products containing titanium dioxide since January 2020, in Australia, however, there seems to be no doubt about its safety. While the United States has very little regulation in this regard.
