Reducing human exposure to arsenic,and simultaneously increasing selenium and zinc intake,by substituting non-aromatic rice with aromatic rice in the diet

Abstract

Hundreds of millions of people world-wide are exposed to high concentrations of the toxic element arsenic (As) through drinking water and consumption of certain foods, especially rice. In this study Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) was used to analyse rice from the greater Sylhet region of Bangladesh which has relatively lower groundwater As concentrations. Different varieties of rice were analysed for inorganic-As (i-As) and other elements (Cd, Mn, Pb, Se and Zn) in order to identify rice with low As content and higher essential element (Zn and Se) content. Sylheti non-aromatic rice showed lower As concentration (27.1–174.1 μg/kg) compared to non-aromatic rice from other regions of Bangladesh. Furthermore, aromatic rice from Sylhet had the lowest As content (10.1 μg/kg) and the highest Se content (341 μg/kg) compared to non-aromatic rice. Approximately 70% of the total As in Sylheti rice was i-As and parboiled rice contained the highest i-As (90%) compared to other rice varieties. Aromatic rice generally contained lower concentrations of toxic elements (As, Cd, Pb) and higher concentrations of essential elements (Se, Zn) compared to non-aromatic rice. For someone consuming 500 g of non-aromatic or aromatic rice from Sylhet, the daily intake of As from consumption of rice would be reduced by approximately 48% and 69%, respectively, compared to non-aromatic rice from other parts of Bangladesh thus far investigated. Also the daily intake of As from consumption of aromatic rice is 40% lower compared to non-aromatic rice sourced from the Sylhet region. The daily intake of Se and Zn from consumption of rice would be increased by 46% and 23%, respectively, for someone consuming aromatic rice instead of non-aromatic rice from Sylhet. This study reveals that consuming certain types of aromatic rice can potentially not only reduce exposure to As but also increase the daily intake of Se and Zn in Bangladeshis. This type of rice could also be used in infant foods instead of rice with higher As concentration.