Association between mediterranean diet and metal(loid) exposure in 4-5-year-old children living in Spain

Even relatively low levels of metals exposure may impact health, particularly among vulnerable populations such as infants and young children. However, little is known about the interplay between simultaneous metal exposures, common in real-life scenarios, and their association with specific dietary patterns. In this study, we have evaluated the association between adherence to Mediterranean diet (MD) and urinary metal concentrations individually and as an exposure mixture in 713 children aged 4-5-years from the INMA cohort study. We used a validated food frequency questionnaire to calculate two MD indexes scores: aMED and rMED. These indexes gather information on various food groups within the MD and score differently. To measure urinary concentrations of cobalt, copper, zinc, molybdenum, selenium, lead, and cadmium as exposure biomarkers, we used inductively coupled plasma mass spectrometry (ICP-MS), coupled with an ion chromatography (IC) equipment for arsenic speciation analysis. We applied linear regression and quantile g-computation, adjusted for confounders, to analyse the association between MD adherence and exposure to the metal mixture. High adherence to MD such as the quintile (Q) 5 MD was associated with higher urinary arsenobetaine (AsB) levels than Q1, with β values of 0.55 (confidence interval - CI 95% 0.01; 1.09) for aMED and 0.73 (CI 95% 0.13; 1.33) for rMED. Consumption of fish was associated with increased urinary AsB but reduced inorganic arsenic concentrations. In contrast, the aMED vegetables consumption increased urinary inorganic arsenic content. A moderate level of adherence to MD (Q2 and Q3) was associated with lower copper urinary concentrations than Q1, with β values of -0.42 (CI 95% -0.72; -0.11) for Q2 and -0.33 (CI 95% -0.63; -0.02) for Q3, but only with aMED. Our study, conducted in Spain, revealed that adhering to the MD reduces exposure to certain metals while increasing exposure to others. Specifically, we observed increase in exposure to non-toxic AsB, highlighting the significance of consuming fish/seafood. However, it is crucial to emphasize the necessity for additional efforts in reducing early-life exposure to toxic metals, even when adhering to certain food components of the MD.

This study was funded by CIDEGENT/2020/050 and grants from Spanish Institute of Health Carlos III, ISCIII-FEDER: PI07/0314, PI11/01007, PI16/1288, PI19/1338, PI04/2018, PI09/02311, PI13/02429, PI18/00909, PIS06/0867, PI09/00090, PI13/02187, PI04/1436; PI08/1151, PI18/01142, PI03/1615, PI04/1509, PI04/1112, PI04/1931, PI05/1079, PI05/1052, PI06/1213, PI07/0314, PI09/02647, PI11/02591, PI11/02038, PI13/1944, PI13/2032, PI14/00891, PI14/01687 and PI17/00663. FIS-FSEE: 7/00260, Red INMA G03/176; CB06/02/0041 incl. FEDER funds. Grants from UE (FP7-ENV-2011 cod 282957 and HEALTH.2010.2.4.5–1). - Generalitat de Catalunya CIRIT 1999SGR 00241, Fundació La marató de TV3 (090430). We acknowledge support from the Spanish Ministry of Science and Innovation and the State Research Agency through the “Centro de Excelencia Severo Ochoa 2019–2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program. Obra Social Cajastur/Fundación Liberbank and Universidad de Oviedo Miguel Servet fellowship (CP16/00128, CP11/00178, CP15/00025, and CPII16/00051) funded by Instituto de Salud Carlos III and cofounded by European Social Fund “Investing in your future”. CIBERESP, Department of Health of the Basque Government (2005111093, 2009111069, 2013111089, 2015111065 and 2018111086), and the Provincial Government of Gipuzkoa (DFG06/002, DFG08/001 and DFG15/221 and DFG 89/17) and annual agreements with the municipalities of the study area (Zumarraga, Urretxu, Legazpi, Azkoitia y Azpeitia y Beasain). Generalitat Valenciana: FISABIO (UGP 15–230, UGP-15-244, and UGP-15-249), and Alicia Koplowitz Foundation 2017. Institute of Health Carlos III(Grant CD21/00186- Sara Borell Postdoctoral Fellowship) and co-funded by the European Union. Spanish Ministry of Universities (Margarita Salas Grant MS21-133) and co-funded by European Union- Next Generation EU. H2020 No 874583, the ATHLETE project. Generalitat Valenciana (CIAICO/2021/132).

Peer reviewed