His M, Lajous M, Gómez-Flores-Ramos L, et al. - This study was carried out to distinguish the potential correlates of these biomarkers to guide future research on potential modifiable determinants of mammographic density. Researchers assessed a total of 132 metabolites (acylcarnitines, amino acids, biogenic amines, glycerophospholipids, sphingolipids, hexose) by tandem liquid chromatography/mass spectrometry in plasma samples from 573 premenopausal participants in the Mexican Teachers’ Cohort. They evaluated the relationships between metabolites and percent mammographic density using linear regression models, adjusting for breast cancer risk factors and accounting for multiple tests. They calculated the mean concentrations of metabolites associated with percent mammographic density across levels of several lifestyle and metabolic factors. New biomarkers associated with mammographic density were distinguished in young women. The relationship of these biomarkers with mammographic density and metabolic parameters may provide new perspectives to support future preventive actions for breast cancer.