More than 20% of the global population suffer from food allergy or intolerance. An environmental origin for these adverse food reactions is strongly suspected. In this context, and for the first time, a team of INRA research scientists in Toulouse has just shown that perinatal exposure to low doses of BPA, which is considered to be risk-free in humans, could increase the risk of developing food intolerance in adulthood.
These findings support the decision made by the French authorities to ban the use of BPA in containers used for infant foods as early as 2013, and in all food packaging as from 2015.
Human exposure to endocrine disruptors, and particularly to bisphenol A, is omnipresent in our daily lives. The potential risks to consumers of this chemical contaminant, which is mainly found in food packaging materials, have been the subject of several, sometimes contradictory, reports from French and international health agencies during the past five years. In April 2013, the French Agency for Food, Environmental and Occupational Health and Safety (ANSES) published an opinion on bisphenol A which recommended limiting exposure to this substance and lowering the toxicological thresholds on which risk evaluations were based. A few months later, the European Food Safety Agency (EFSA) also proposed applying to bisphenol A a limit value that was ten times lower than that previously applicable, or 5µg/kg body weight/day.
Scientists in INRA's Joint Research Unit for Food Toxicology (TOXALIM) in Toulouse have demonstrated in rats that perinatal exposure (in utero and during suckling) to bisphenol A (BPA) at low doses had effects on development of the immune system and predisposed their progeny to food intolerance in adulthood.
During their work, the INRA researchers used two groups of gestating rats. One group received a daily oral dose of BPA of 5 μg/kg body weight, from gestation until the weaning of newborns at 21 days, while the other (control) group did not receive any BPA. The newborns from these two groups were then studied. In adulthood, or at the age of 45 days, these animals were fed with ovalbumin, an egg white protein, which had not previously been included in their diet. The scientists then observed an immune reaction directed against ovalbumin among the animals that had been exposed to BPA during their development. However, rats descending from the control group developed a food tolerance of ovalbumin, which resulted in a lack of immune response. Furthermore, repeated oral administrations of ovalbumin in the rats exposed via their mothers to BPA induced colonic inflammation that testified to a food intolerance.
During this INRA study, the scientists tested different doses (0.5, 5 and 50 μg/kg body weight/day) and demonstrated a non-linear relationship between the BPA doses and the undesirable effects observed. In particular, the most marked disturbances were observed at a dose of 5 μg/kg body weight/day, or in other words the dose considered by the EFSA to be risk-free in humans. These findings have therefore highlighted the problem of determining a safe and tolerable daily dose for BPA.
These new results have contributed to characterising the harmful effects of BPA on the immune system at low levels of exposure and at the ages during which individuals are particularly vulnerable because of their immaturity: the foetus and neonate.
These findings support the decision made by the French authorities as early as 2013 to ban the use of BPA in containers used for infant foods, and in all food packaging materials in 2015. The methods developed to study the effects of BPA on the immune system could be applied to other endocrine disruptors, and particularly to substances that might be used instead of BPA in new-generation food packaging materials.
This study was carried out by teams from the Joint Research Unit for Food Toxicology (Toxalim) at the Toulouse Midi-Pyrénées Research Centre. It was funded by INRA's Nutrition, Chemical Food Safety and Consumer Behaviour Division and the French National Research Agency in the context of the PERINATOX project that has been coordinated by Eric Houdeau since 2010.
