There is some science at universities on kosher food. scientists e.g. found out that eating pig meat affects the Human DNA and creates damages.
And thhere is also some sciences regarding the vitamins in vegatables if they are cooked kosher.
Even if view to kosher bread there are differences compared to none kosher breads.
Probably the most logical assumption is, that in old Egypt, Babylon and Israel the priests also were doctors. The knowledge of the old cultures found its part in the religion to help humans simply to live healthy. If you want so, its a reward of God if you follow the rules.
Now in the 21.th centry we are slowly discovering how food affects us and why the old religious doctrines reflect wisdom.