Even ingested in low doses, this heavy metal causes a strong activation of antibodies which can cause a serious allergic reaction.
- Classified among heavy metals, cadmium increases, when ingested, inflammatory reactions in case of allergy.
- Its ingestion changes the intestinal microbiota and increases the production of enzymes that degrade vitamin D, leading to a deficiency.
- It is this vitamin D deficiency that increases allergic symptoms.
Classified as a heavy metal toxic to the body and the environment, cadmium has long been used in the composition of many alloys with other metals, for the manufacture of television screens or even batteries.
Although its use, particularly in fertilizers, is now supervised and limited in the European Union, cadmium remains a component that is regularly found in polluted soils and waters, and can contaminate certain foods, such as fruits. seafood, fish or vegetables.
Numerous studies have documented the deleterious effects of cadmium on health. Prolonged exposure may cause kidney damage, bone fragility, effects on the respiratory system, reproductive disorders and an increased risk of cancer. Cadmium is also suspected of causing effects on the liver, blood and immune system.
In a study published in the journal Mucosal Immunology, researchers have shown in mice that ingestion of cadmium leads to an overproduction of an enzyme that degrades vitamin D, which produces a deficiency. In terms of clinical effects, mice sensitized to a specific allergen that consumed cadmium produced high levels of antibodies against the allergen as well as immune cells that increased their respiratory symptoms.
A stronger allergic reaction
Previous studies have already shown that in children, vitamin D deficiency leads to a greater susceptibility to asthma and other allergy symptoms. However, this exposure to cadmium can promote vitamin D deficiency in toddlers and children.
“The problem is that because cadmium doesn’t break down easily, if you’re chronically exposed to low doses, it builds up over time.says Prosper Boyaka, a professor at Ohio State University and lead author of the study. It’s also not something you can easily avoid being exposed to as it can linger in the air, soil and water.”
To assess the allergic risk of cadmium ingestion, the researchers had mice genetically modified to simulate human genetic predisposition to egg allergy consume water containing this heavy metal for 28 days.
These mice were then exposed to an egg protein to test their allergic reaction.
The results show that rodents that ingested cadmium and then exposed to the allergen had a stronger allergic reaction – in the form of internal inflammatory actions and allergy symptoms – than control mice.
An alteration of the intestinal microbiota
According to the researchers, this allergic reaction occurred because cadmium changes the population of microbes in the gut, which can lead to allergic reactions.
Further research allowed them to see a link between the presence of cadmium in the intestine and the production of inflammatory molecules, as well as with the stimulation of the two enzymes that degrade vitamin D.
“This is the main conclusion: after exposure to subtoxic doses of heavy metals, the pollutants remain in the soft tissues, including the intestine. And what they do is make the cells more reactive. In the gut, in particular, bacteria cause certain cells to produce more enzymes that break down vitamin D.”explains Professor Boyaka.
According to the researchers, however, it would be possible to block this action of cadmium through vitamin D supplementation. But this “must intervene before exposure to cadmium has caused an increased allergic reaction”. “We also propose targeting these enzymes as a way to prevent the allergic reaction from increasing.”
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