Food contaminants including dioxin, PCB, and BPA may increase the risks of obesity by worsening metabolic responses, warn researchers.
The study, published in The Faseb Journal, introduced a ‘cocktail’ of contaminants - mixed with low doses of dioxin, PCB, bisphenol A (BPA) and phthalates - into the feeding of mice that had already been rendered obese by a high-fat diet.
Led by Brigitte Le Magueresse Battistoni of INSERM , France, the study found that the addition of low level contaminants resulted in metabolic changes in mice – but noted that the effects seen differ between males and females.
The team revealed that females appeared to be more affected by the contaminants, with obesity-induced glucose intolerances worsened and oestrogen pathways was altered.
"With this study, we have succeeded in providing proof-of-concept that low doses of contaminants, even at levels normally considered to be without health impacts in humans, do in fact affect humans when subjected to chronic exposure, and when the contaminants are combined with a high-calorie diet" said Le Magueresse Battistoni.
Le Magueresse Battistoni and her team added two environmentally persistent contaminants (dioxin and PCB) and two non-persistent contaminants (phtalate and bisphenol A) to the high-fat (obesogenic) diet of the mice in low doses that are normally considered not to have any health impacts.
These products were chosen because they are present in human food and because they are known to trigger endocrine disruption, the team noted. In parallel, a control group of mice was fed with the same obesogenic diet, but without added contaminants.
“We hypothesized that life-long consumption of a high-fat diet that contains low doses of pollutants will aggravate metabolic disorders induced by obesity itself,” the team said.
Analysis showed that the effects of these contaminants were highly dependent on the gender of the animal, with females suffering from worsened glucose intolerance and altered the oestrogen pathway.
In males, the low level contaminants were seen to alter cholesterol and lipid metabolism.
There were no changes in weight between the exposed mice and the unexposed mice.
“Because of the very low doses of pollutants used in the mixture, these findings may have strong implications in terms of understanding the potential role of environmental contaminants in food in the development of metabolic diseases,” the team warned.
Source: The Faseb Journal
Published online head of print, doi:10.1096/fj.13-231670
“Low-dose food contaminants trigger sex-specific, hepatic metabolic changes in the progeny of obese mice”
Authors: Danielle Naville, Claudie Pinteur, Nathalie Vega et al