People can possibly develop type 2 diabetes from eating brown rice. According to studies, consuming foods with unsafe levels of arsenic has been linked to diabetes.
Sources:
http://www.consumerreports.org/cro/magazine/2012/11/arsenic-in-your-food/index.htm
http://www.ncbi.nlm.nih.gov/pubmed/9302338
http://www.ncbi.nlm.nih.gov/pubmed/2822877
