Arsenic exposure through wheat may increase cancer risk
doi:10.1038/nindia.2019.162 Published online 11 December 2019
Research has identified an increased cancer risk from wheat-based food intake in a rural population of the eastern Indian state of Bihar, where exposure to arsenic is prevalent1.
Next to rice, wheat is the most important food-grain for millions of Indians, particularly in the northern and north-western parts of the country. However, arsenic exposure from wheat, including wheat-based food, remains largely unexplored.
To find out, an international research team, including scientists from the Mahavir Cancer Sansthan and Research Centre, A. N. College and Aryabhatta Knowledge University, all in Patna, India, assessed the risk of arsenic exposure through wheat and wheat flour intake. They did so by studying people from 77 households across 19 villages in 10 arsenic-affected districts of Bihar.
Analysing wheat grain and wheat flour samples, the researchers found that the mean total arsenic concentration in wheat grains is higher than the reported concentrations in wheat from a previous study in Bihar.
When milled, whole wheat grains generate bran and white flour fractions. This process results in a three- to- four-fold higher arsenic concentration in the bran than in the white flour, keeping most of the whole grain arsenic in the bran.
However, the new study detected an overall increase in arsenic levels in both wheat grain and wheat flour.Since arsenic is a potential carcinogen, the estimated lifetime cancer risk of the studied arsenic-exposed population from Bihar indicated a risk higher than that of threshold arsenic exposure values determined by the US-based Environmental Protection Agency.
1. Suman, S. et al. Wheat is an emerging exposure route for arsenic in Bihar, India. Sci. Total. Environ. 703, 134774 (2020)