Choi IY , Lee P , Denney DR , Spaeth K , Nast O , Roth AK , Lierman JA , Sullivan DK. - 46019 N - Am J Clin Nutr 2015 ; in press.
Objective: We tested the hypothesis that dairy food consumption is associated with cerebral glutathione concentrations in older adults.
Design: In this observational study, we measured cerebral glutathione concentrations in 60 healthy subjects (mean ± SD age: 68.7 ± 6.2 y) whose routine dairy intakes varied. Glutathione concentrations were measured by using a unique, noninvasive magnetic resonance chemical shift imaging technique at 3 T and compared with dairy intakes reported in 7-d food records.
Results: Glutathione concentrations in the frontal [Spearman’s rank-order correlation (rs) = 0.39, P = 0.013], parietal (rs = 0.50, P = 0.001), and frontoparietal regions (rs = 0.47, P = 0.003) were correlated with average daily dairy servings. In particular, glutathione concentrations in all 3 regions were positively correlated with milk servings (P = 0.013), and those in the parietal region were also correlated with cheese servings (P = 0.015) and calcium intake (P = 0.039). Dairy intake was related to sex, fat-free mass, and daily intakes of energy, protein, and carbohydrates. However, when these factors were controlled through a partial correlation, correlations between glutathione concentrations and dairy and milk servings remained significant.
Conclusions: Higher cerebral glutathione concentrations were associated with greater dairy consumption in older adults. One possible explanation for this association is that dairy foods may serve as a good source of substrates for glutathione synthesis in the human brain.