It is true that nowadays diabetes occurs more often in Jews than non-Jews. Sure, others do suffer from diabetes, but today the Jews especially often suffer from this ailment. The Jewish people have difficulties assimilating sugar, on the other hand, they do need it. So it would be important for them to have a diet that makes it easy for the body to use the sugar and not process it right away.
If you read the Old Testament, then you will find all kinds of food regulations, rules that are to this day observed in the restaurants where ‘kosher’ food can be ordered. You will know such restaurants; With Jewish letters, it is indicated that they offer ‘kosher’ meals. The cooking is kosher in such restaurants. That is, the food is prepared according to the ancient rules of Moses.
And if you examine what is actually behind these rules, then you will find that the reason is to make it possible for the Jewish person to eat in such a way as to make it easier to handle the sugar, because sugar is difficult for them to handle. In particular, the prohibition of pork – for pork is generally much more difficult to process for the human being – was designed to prevent diabetes. One must be able to read the Old Testament even medically; then it becomes very interesting.
Source (German): Rudolf Steiner – GA 348 – Über Gesundheit und Krankheit – Dornach, January 13, 1923 (page 261)
Translated by Nesta Carsten-Krüger