**10. Future direction**

In last two decades, there has been great progress in development of biomarkers of oxidative stress that may eventually be useful in disease prevention. The challenges for future miRNA studies are (1) to validate available biomarkers for oxidative stress in animal and human studies based on their specificity, stability for storage, reproducibility, causal relation with disease, and response to antioxidant intervention; (2) to examine the basal lebels of oxidative damage in healthy subjects; and (3) to assess the long-term effect of antioxidants, such as oats, on oxidative damage by well-designed, randomized, controlled trials in human and as well as to examine the consistency of the findings among various studies. The identification of miRNAs as biomarkers of oxidative damage, if validated, may open the way for the development of early detection and prevention strategies for oxidative stress-associated human diseases.
