Canned foods, and specifically canned foods: are they safe for health? According to this research , which analyzed the percentage of zinc in some canned foods that are naturally low in zinc, such as tuna, asparagus, corn, eating foods in cans would expose us to excessive doses of zinc. In the case of tuna, a food that in nature, when fresh, contains low doses of zinc (0.8 mg per 100 grams of food), and which canned contains 0.1 milligrams more, the researchers of the University of Binghamton of New York found that when tuna is canned, the percentage of zinc becomes 100 times higher than what is considered safe for health.. To arrive at this figure, the researchers analyzed samples of canned tuna with a spectrometry. The explanation for this contamination is in the addition of an additive such as zinc oxide: zinc  oxide is used to promote the preservation of canned food , and nanoparticles of this substance are absorbed by the food, and in particular they are concentrated in the deposit liquid.
But what effect does this excess of zinc have on our health?
The researchers have for the moment analyzed the effect that this excess of zinc would have on the intestinal villi, but in vitro, so they cannot be sure of what actually happens in people: however, the intestinal villi would have suffered damage in contact with the percentages of zinc found in canned foods, therefore it is hypothesized that such contamination could expose people to problems such as intestinal permeability syndrome , but also gastric problems such as nausea, vomiting, intestinal colic.