The researchers then ran glucose tolerance and insulin sensitivity tests. They measured the livers for lipid accumulation and the expression of certain genes that play key roles in the metabolism of the adult mice.
The results show that the effects are highly dependent on the gender of the animal.
Male and female: different effects
In the females fed with a high-fat diet, the addition of contaminants worsened the glucose intolerance and altered the estrogen pathway. In males, it altered the cholesterol and lipid metabolism. There was no change in weight between the exposed mice and the unexposed mice.
The researchers pursued the hypothesis that there was a connection between the observed glucose intolerance and the alteration in the estrogen signaling in exposed females. It is well known that estrogens protect against metabolic disorders. In other words, these works suggest that in obese females, exposure to food contaminants could lower the protection level that estrogens provide against metabolic disorders.
"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" points out Brigitte Le Magueresse Battistoni.
|Contact: Brigitte Le Magueresse Battistoni|
INSERM (Institut national de la sant et de la recherche mdicale)