Adherence to Mediterranean diet and metal exposure during childhood in the INMA study

BACKGROUND AND AIM The Mediterranean diet (MD) has been shown to have beneficial effects in children. A greater adherence to this pattern has been associated with a lower risk of developing obesity, diabetes, and cardiovascular disease. Yet, the contribution of the MD to the ingestion of essential and non-essential elements during childhood is unknown. Here, it is investigated the association between children’s adherence to the MD and exposure to essential and non-essential elements. METHODS Our study population of 714 children come from the INMA cohort study (INfancia y Medio Ambiente). Urinary concentrations of essential (Co, Cu, Zn, Se, and Mo) and non-essential (As, Pb and Cd) elements were measured as exposure biomarkers. Urinary arsenic speciation was also determined, and concentrations were adjusted for urine dilution. The MD dietary indexes rMED (relative Mediterranean Diet Score) and aMED (alternate Mediterranean Diet Score) were calculated based on the information gathered with a validated food frequency questionnaire (FFQ). The urine samples and data from FFQ were collected at 4 years of age. RESULTS The median urinary concentrations of Co, Cu, As, Se, Mo, Cd, Pb and Zn were 0.78, 7.64, 24.45, 23.07, 92.76, 0.08, 0.37 and 377.39 μg/L, respectively. Urinary arsenic species concentrations (median) included arsenobetaine (10.83 μg/L), monomethylarsonic acid (0.36 μg/L), dimethylarsinic acid (3.00 μg/L), and inorganic arsenic (1.17 μg/L). An increased adherence to MD was associated with higher Mo, As and lower Co concentrations. The non-toxic arsenobetaine was associated with fish consumption in both indexes, but vegetables consumption was related to the inorganic arsenic exposure only in aMED index. CONCLUSIONS These findings suggest that the level of adherence to the MD is associated with exposure to essential but also non-essential elements. Efforts should aim to reduce toxic dietary exposures while preserving beneficial nutrients in children’s dietary patterns. KEYWORDS Mediterranean Diet, Metals, Childhood