A new study has found that the carcinogenic effect of a cocktail of substances is greater than the effect of the individual substances added together.
This would mean that government regulations pertaining to the levels of toxic substances in foods are probably inadequate.
“Our study shows that if we don’t take the cocktail effect into account when determining the limit values for potentially carcinogenic substances, we tend to set the limit values too high,” says Kristian Syberg, associate professor at the Department of Environmental, Social and Spatial Change (ENSPAC) at Roskilde University.
“The cocktail effect of potentially carcinogenic substances is so great that the limit values need to be set even lower if we’re to have the desired safety margin for concentrations of the substances,” he added. If you don’t take the cocktail effect into account, then you underestimate the toxicity of the substances in the environment, said Syberg. “That’s scary.”
In the study, Syberg examined the combination effect of two pesticides and the substance acrylamide, which is typically found in breads, coffee, potato chips and other types of food.
Each substance individually is potentially a carcinogenic, but added together the carcinogenic effect is far greater, the study showed. Syberg exposed cells to a combination of the three substances and found that the cocktail did more damage to the DNA, even in concentrations of the individual substances so low that they would have no effect on their own.
Researchers used high concentrations of the potentially carcinogenic substances because the exposure only lasted 48 hours.
Scientists set limit values for the discharge and use of certain substances after they study how small a quantity of a substance it takes to have a harmful effect on cells, humans or animals, as well as whether the substances can cause cancer or disrupt endocrines.
This study shows, though, scientists cannot assume that cells, humans and animals will react in the same way to the substances individually as they do when the substances are part of a cocktail.
The research findings were published in the Journal of Toxicology and Environmental Health.