Interview with Grégory Bouchaud by the Foundation for Medical Research

Allergies are on the increase all over the world, particularly in children, posing a real public health problem. The researchers believe that chronic exposure to several pesticides simultaneously, even at low doses during pregnancy and breastfeeding, could influence the development of food allergies and asthma in children. They wish to explore this aspect, which could guide future prevention strategies and recommendations to the general public.

Allergies: a global problem potentially linked to pesticides

According to the World Health Organisation, allergies are on the increase. They affect 20% of people worldwide, and half the population could be affected by 2050. Pesticides, through their effects on the immune system, appear to be contributing to this increase in allergies.

Are children more affected?

Children may be more affected, because their immune systems and organs are immature, and the period around birth (pregnancy and breastfeeding) is particularly sensitive. What's more, having a food allergy in childhood increases the risk of developing asthma later in life. It is therefore crucial to understand the consequences of multiple exposures to pesticides, even at low doses before and after birth, in order to assess this risk, which is the aim of Grégory Bouchaud's research. The researcher is particularly interested in the combined effect of these pesticides at doses which, taken individually, have no proven deleterious effect: this is known as the cocktail effect.

Observing the effect of pesticides during development

Using a mouse model, the team will explore the ‘cocktail’ effect of a mixture of six pesticides on the development of food allergies and asthma. These pesticides, commonly used in the European Union, will be tested at doses lower than those authorised by regulations. The animals will be fed a diet containing this mixture during gestation and suckling, and then this diet will be maintained for the young, at which point the researchers will observe the development of their immune systems to see if there are any disturbances during maturation. They will also look at the development of the animals' respiratory and digestive systems and their intestinal flora. The final stage will involve measuring pesticides in the blood of allergic pregnant women, and then in that of their children, and correlating the degree of exposure with the risk of allergy. This project will thus enable a better assessment of the risks associated with pesticides in the onset and triggering of allergies. The ultimate aim is to define effective prevention strategies and give recommendations on authorised doses, taking into account the ‘cocktail effect’.

Meet Grégory Bouchaud, project leader