Kosher Diet


Kashrut or Kashruth or “keeping kosher” is the name of the Jewish dietary laws. Food in accord with halakha (Jewish law) is termed kosher in English, from the Hebrew term kasher, meaning “fit” (in this context, fit for consumption by observant Jews).
Food not in accord with Jewish law is termed treifah or treif (“torn”); the term originally referred to animals (from a kosher species such as cattle or sheep) which had been either incorrectly slaughtered or mortally wounded by wild beasts and therefore were not fit for human consumption. Among Sephardim, it typically only refers to meat that is not kosher.
The basic laws of kashrut are in the Torah’s Book of Leviticus, with their details set down in the oral law (the Mishnah and the Talmud) and codified by the Shulkhan Arukh and later rabbinical authorities. Many varied reasons have been offered for these laws, ranging from philosophical and ritualistic, to practical and hygenic; see below for examples and explanations.
Jews as a separate people, similar to the concept of reproductive isolation in speciation. Just as two species who can interbreed will merge into one, the theory of cultural evolution requires a degree of social separation for two cultures to remain distinct entities. The laws of Kashrut had the effect of preventing socialization and intermarriage with non-Jews, helping the Jewish community maintain its identity. Wenham writes that
“circumcision was a private matter, but the food laws made one’s Jewish faith a public affair. Observance of the food laws was one of the outward marks of a practising Jew, and this in turn enhanced Jewish attachment to them as a reminder of their special status” (Gordon J. Wenham, “The Theology of Unclean Food,” The Evangelical Quarterly 53, January March 1981, p.6-15).
There have been attempts to provide empirical support for the view that kashrut laws have hygienic benefits. However, this has never been the traditional Jewish view.
It was believed by some people that kosher animals were healthier to eat than non-kosher animals. It was also noted that the laws of purity (Leviticus 1115) not only describe the difference between clean and unclean animals, but also describe other phenomena that appear to be related to health. For instance, glatt, the requirement that lungs be checked to be free of adhesions, would prevent consumption of animals who had been infected with tuberculosis; similarly, the ban on slaughtering of an unconscious animal would eliminate many sick and possibly infectious animals from being consumed. Such a rationale seems reasonable when considering the laws prohibiting the consumption of carrion birds or birds of prey (which are advantageous scavengers), as they may carry disease from the carrion they consume; shellfish, which as filter feeders can accumulate harmful parasites or toxins; or pork, which can harbor trichinosis if not properly cooked. Thus, it was natural for many to assume that all the laws of kashrut were merely hygienic in intent and origin. One of the rabbinical authorities that mention the hygiene hypothesis is Maimonides in his Guide for the Perplexed.
For a number of reasons, however, this idea has fallen out of favor among biblical scholars, and has never been accepted by the majority of Jews. Fruits and vegetables may be eaten without prohibition even though there are many poisonous herbs, seeds, berries and fruits. Additionally, this hypothesis does not explain other parts of the Jewish dietary laws; for instance forbidding the consumption of fish without true scales, such as sharks and swordfish, fruit from trees which are less than four years old, or residual blood in meat.
In 1953 Dr. David I. Macht performed experiments on many different kinds of animals and fish, and concluded that the concentration of zoological toxins of the “unclean” animals was higher than that of the “clean” animals, and that the correlation with the description in Leviticus was 100%. In addition, the research indicated harmful physiological effects of mixtures of meat and milk, and ritually slaughtered meat appeared to be lower in toxins than meat from other sources. The conclusions of this paper were challenged in a paper by prominent biologists written at the request of a Seventh-day Adventist Church publication .
Other reasons
Like the laws for the slaughter of animals, laws against shellfish could actually be for the good of the creature. There is no painless method for the preparation of “bottom-feeding” lobster and crab.
It is also possible that there are multiple reasons for the laws of Kashrut, with each law serving one or more-than-one purpose.