Judiasm 101 has some interesting insights into Jewish dietary laws, although the author states,
However, health is not the only reason for Jewish dietary laws. Many of the laws of kashrut have no known connection with health. To the best of our modern scientific knowledge, there is no reason why camel or rabbit meat (both treif) is any less healthy than cow or goat meat.
I don't know how much I agree with that statement.
The basic tenets:
Certain animals may not be eaten at all. This restriction includes the
flesh, organs, eggs and milk of the
Of the animals that may be eaten, the
birds and mammals must be killed in
accordance with Jewish law.
All blood must be drained from meat
and poultry or broiled out of it
before it is eaten. Certain parts of
permitted animals may not be eaten.
Fruits and vegetables are permitted,
but must be inspected for bugs (which
cannot be eaten)
Meat (the flesh of birds and mammals)
cannot be eaten with dairy. Fish,
eggs, fruits, vegetables and grains
can be eaten with either meat or
dairy. (According to some views, fish
may not be eaten with meat).
Utensils (including pots and pans and
other cooking surfaces) that have come
into contact with meat may not be used
with dairy, and vice versa. Utensils
that have come into contact with
non-kosher food may not be used with
kosher food. This applies only where
the contact occurred while the food
Grape products made by non-Jews may
not be eaten.
There are a few other rules that are
We may not eat animals that died of natural causes (Deut. 14:21) or that were killed by other animals. In addition, the animal must have no disease or flaws in the organs at the time of slaughter. These restrictions do not apply to fish; only to the flocks and herds (Num. 11:22).
Back to the camel/rabbit issue; both are carriers of diseases which can affect man. Since the aforementioned diseases would also affect various organs of the animals, they would not be considered edible under Jewish dietary law. Shellfish, clams etc - you can't see the organs of them to know whether or not they're clean - therefore they aren't edible.
As far as not eating something that keeled over dead one day... that should be a no-brainer, as is the case with carrion - rabies Since sanitation and food preparation left MUCH to be desired, foods which were 'risky' were banned, as were any animals known to commonly carry diseases which could affect men.