An article in Tech Times dated June 7, 2014, presents a case for an unintended side-effect of fasting, namely the "re-generating" of stem cells.
"Damaged and older cells" were destroyed in the process. The article states that "This process is akin to recycling for the immune system."
The process is held to be particularly valuable for persons undergoing chemo-therapy.
The Tech Times article can be accessed here.
Orthodox Christians undertake fasting for its spiritual values, but given the Church's traditional inclusion of the body within our ascetic practices, it seems that the spiritual blessings derived from integral fasting are extensive indeed.