Regarding changing genes: this is what I do, in induced pluripotent stem cells by gene targeting/genome editing, but all this is not, and will not be for a while, available for human clinical treatments. Concerning epigenetics: yes there are some studies on nutrition and epigentics but I am not that sure how would these apply to your case. In general epigenetics is a more an in vitro dicipline connected to chromatin modification analysis and whole organisms in vivo studies on epigenetics are not the rule.