A great deal of evidence today points to the influence of the environment and diet on health, from as early as the foetal stage. In response to a request from the Directorate General for Health, ANSES conducted two expert appraisals focusing on breastfeeding:
 

• an assessment of the risks associated with exposure of breastfed children to chemical contaminants, following on from its infant total diet study (iTDS);
• a review of knowledge on the nutritional benefits of breastfeeding for child health. 

This work was carried out as part of the French National Health and Nutrition Programme (PNNS) and the Government's action plan targeting the first 1000 days of a child's life, from the in utero period through to the age of two.

Presence of substances resulting from environmental contamination

In this first expert appraisal, ANSES estimated the levels of chemical exposure of children under six months of age via breast milk and foods introduced during complementary feeding. Thirty-two substances or classes of substances were examined, based on scenarios simulating many different exposure situations. For most of the substances studied, the level of exposure was of little concern to health: 20 of them did not exceed the health reference values for dietary exposure.

However, for 12 substances or classes of substances, ANSES showed that the level of exposure of breastfed children could exceed the health reference values. These were trace metal elements (inorganic arsenic, cadmium, chromium, manganese, nickel and lead), polychlorinated compounds (PCBs, dioxins and lindane), polyfluoroalkyl substances (PFOSs and PFOAs) and polybrominated compounds (PBDEs). These substances are found in various foods, water and air.

The estimate of exposure to contaminants in breast milk drew on a study called CONTA-LAIT, which was based on an analysis of 180 samples of breast milk collected in various major regions of France between 2013 and 2015. It was carried out by ANSES, the Paris public hospital system (AP-HP), the LABERCA (Oniris VetAgroBio) and the Ultra Traces Analyses Aquitaine (UT2A) chemical testing laboratory.

For contaminants found in other infant foods, the expert appraisal incorporated data produced by the infant total diet study (iTDS). This study, published by ANSES in 2016, assessed the dietary exposure of non-breastfed children under three years of age to chemical contaminants. The analyses concerned 670 substances screened for in infant formulas and foods introduced during complementary feeding. 

Collective action to reduce environmental and food contamination

The results of this expert appraisal are not intended to predict the future health of breastfed children. However, they do emphasise that there is a need for collective action on 12 substances of concern.

Most of the chemicals identified as problematic are known to contaminate the environment over the long term and accumulate in the fatty or bone tissues of the human body. Their presence in breastfeeding mothers therefore results from cumulative past exposure. Infants' exposure to metal contaminants comes mainly from the foods that are usually introduced during complementary feeding.

As these substances occur widely in the environment and in foods, it is not generally appropriate to recommend that women take individual action to limit exposure for themselves and their children. However, in 2019, ANSES issued recommendations on fish consumption for pregnant and breastfeeding women in order to control exposure to chemical contaminants in this food group.

ANSES now calls for a strengthening of the collective action already undertaken by the public authorities to reduce contamination of the environment and foods. In particular, this should include regulating substances, identifying and controlling sources of contamination and monitoring the food chain.

The expert appraisal also highlighted the need for further studies. In particular, breast milk contamination in France needs to be described in more detail and monitored over time, along with its possible impact on the development of young children.

Confirmation of the nutritional benefits of breast milk for child health

At the same time, ANSES conducted a review of scientific knowledge on the nutritional benefits of breast milk for child health. This expert appraisal drew on numerous epidemiological studies that demonstrated these benefits.

ANSES's conclusions confirmed the positive relationship between the consumption of breast milk and a reduced risk of overweight at all ages, as well as a favourable effect on cognitive development. Evidence also suggests that breastfeeding may help reduce the risk of type 1 diabetes, leukaemia and acute otitis media (although only up to the age of two for the latter).

For maternal and child health, ANSES reiterates the importance for pregnant and breastfeeding women to follow specific dietary recommendations, in order to meet their increased nutritional needs during this period.

In addition to the work carried out by ANSES on the health effects of breast milk, the Directorate General for Health also asked the High Council for Public Health (HCSP) to draw up recommendations on the practice of breastfeeding in France.

In the second edition of its Epifane survey, published in July 2024, Santé Publique France also reported an increase in the practice of breastfeeding in France.