Epigenetic phenomena of arsenic and histone tail modifications: Implications for diet and nutrition

Naturally occurring inorganic arsenic has been identified as the causal agent in human skin, lung, bladder, liver, and prostate cancers. Furthermore, arsenic exposure has also been associated with noncarcinogenic health outcomes, including cardiovascular disease, neurologic deficits, neurodevelopmental deficits in childhood, and hypertension. According to the Agency for Toxic Substances and Disease Registry, arsenic is considered number one on the substance priority list. However, the overall risks on human health may exceed the documented levels due to lack of a comprehensive consideration of exposure through diet and anthropogenic factors. Arsenic permeates through water and soil, and related health issues elicit global concerns for the mass public. The exact mechanism of arsenic toxicity is still not fully understood, although convincing evidence and recent advance in epigenetic research such as DNA methylation and histone posttranslational modifications have broadened our scope in understanding the mechanism of arsenic toxicity and carcinogenicity. This chapter will present the most recent literatures on the effect of arsenic on histone tail modifications as well as implications on food and diet.