The path from contaminants in food to an allergic reaction

It is well known that exposure to the heavy metal cadmium can irritate the stomach, lungs or cause kidney disease, but new research links another health problem to the inadvertent intake of low doses of pollutants: high activation of antibodies can cause allergic reactions

Researchers tracked this connection in mice and found that gut bacteria overproduce an enzyme that degrades vitamin D when exposed to cadmium—effectively creating an environment similar to vitamin D deficiency

Another epidemiological study showed that vitamin D deficiency in children is associated with a high susceptibility to asthma and other allergic symptoms

"The problem is that because it is not easily degraded, cadmium has a half-life of at least 15 years in the body - if you are exposed to low doses for a long time, it accumulates over time," said Boom Boyaka, a professor and chair of the Ohio State University's Veterinary Biological Sciences and The senior author of the study

Most people ingest the natural element cadmium, a heavy metal used in batteries and in the manufacture of pigments, by eating animal and plant foods that have absorbed pollutants or drinking contaminated water

Boyaka and his colleagues found that an experimental compound that inhibits activating enzymes can reduce allergic reactions in mice that ingest cadmium

Boyaka said: "We have proposed two possible strategies in the paper

This research was recently published in the journal Mucosal Immunology

Boyaka said that environmental pollutants, such as cadmium and lead, as well as genetic susceptibility and overuse of antibiotics, are thought to be contributing factors to more and more people's allergies, but the mechanism behind this association is unclear

In this study, the researchers added a dose of cadmium that is considered "subtoxic" to the drinking water that a group of mice drank for 28 consecutive days

Mice drank water containing a subtoxin dose of cadmium and then exposed to the allergen.

"Our hypothesis is that cadmium will change the microbial population in the intestines, because we know that ecological disorders or changes in the microbiota can trigger allergic reactions

As expected, this effect will occur in the intestines, because sterile mice that were orally administered cadmium did not produce too many antibodies that cause allergic reactions, and sterile mice lacked microbes in their intestines

"This is the main finding-after exposure to subtoxic doses of heavy metals, pollutants are still present in soft tissues, including the intestine

Boyaka's laboratory is currently investigating compounds that may be used to prevent vitamin d degrading enzymes