How much does the carcinogenic risk of inorganic arsenic exposure from rice increase with higher brown rice consumption? An estimation for five regions around the world.

Substituting brown rice for white rice can increase the carcinogenic risk of inorganic arsenic (iAs) exposure, given that brown rice has a higher iAs content than white rice. This study estimated changes in the incremental lifetime cancer risk (ILCR) of iAs exposure from rice with increases in the proportion of brown to total rice consumption (PBT) in five regions around the world, including North America, Latin America, Europe, Asia, and Oceania. The results demonstrated that the magnitude of the increase in the ILCR of iAs exposure from rice expressed as an increase in PBT, ranged from 0.02 to 0.43 per 10,000 people for each 10 % increase in PBT. The highest increase was observed in Asia, followed by Latin America, North America, Oceania, and Europe. The daily rice consumption rate rather than the increase in iAs content is the critical factor responsible for regional differences in higher carcinogenic risk with increased PBT. This study also suggests that when considering the carcinogenic risks of iAs exposure from rice, substituting brown rice for white rice is feasible in North America and Europe but not in Asia and Latin America, while in Oceania, a partial substitution of brown rice for white rice (<55 %) is feasible.