(P10-02-26) Effects of Lentils Supplementation on Micronutrient Status in Arsenic-Exposed Rural Bangladeshi Population

Objectives: Lentils are protein- and mineral-rich staple food in Bangladesh. Given their macro- and micronutrient composition, lentils may strengthen antioxidant defense mechanisms, improve health status, and help maintain plasma mineral balance.

Methods: In a randomized clinical trial (NCT02429921) among chronically arsenic (As)-exposed rural Bangladeshi healthy adults, we previously demonstrated that selenium (Se)-rich lentil supplementation enhanced erythrocyte [Se] and urinary As excretion. Participants (n=400) were assigned to receive 65 g/day of either Se-rich lentils (containing RDA level of 55 µg Se), or low-Se lentils (2 µg Se) for six months. The macro-, micro- (minerals and folate), and metals (As and Se) contents of both lentil types were analyzed and found to be similar except for Se concentration. In this secondary analysis, we aimed to assess the changes in plasma minerals (sodium (Na), potassium (K), magnesium (Mg), copper (Cu), zinc (Zn), iron (Fe), phosphorus (P) by ICP-MS) and vitamins (folate and Vitamin B12 (B12), by biochemical autoanalyzer) following lentil supplementation. A mixed-effects linear regression model was employed to evaluate changes in minerals and vitamins over time.

Results: Lentil supplementation increased Na (Se-group: β=6.9; control: β=3.7) and folate (Se-group: β=0.83; control group:β=0.68,) but decreased B12 concentrations significantly (Se-group: β=-47.6, control: β=-41.3) in plasma in both groups. Lentil supplementation led to decline in plasma K, Mg, Cu and Zn levels. However, only the control group showed reduction in P (β=-0.19, 95%CI=-0.33, -0.06). No significant change in Fe status was observed.

Conclusions: Although both lentil types contained substantial minerals and folate, only folate levels increased, while other plasma minerals did not improve. The decline in B12 likely reflects dietary substitution, as increased lentil intake may have reduced consumption of animal-source foods (primary source of B12). The decline in plasma minerals may be affected by phytate content of lentils (mean 43 µg/65 g). Combined interactions of As-P-Se may affect plasma P levels. Mechanistic studies are needed to understand the effects of chronic As exposure on mineral metabolism and absorption.

Funding Sources: Original study was funded by Grand Challenges Canada, GIFS & micro-nutrient assessment was by icddrb.