Support Denmark, don't buy Arla Foods
Arla probably also agreed not to trade with Israel. I can't imagine Novo Nordisk not to trade with Israel, but I guess maybe some of the others of the affected companies somehow had a agreement with the arab states not to trade with Israel.
Personally, I really dislike Arlas monopoly in Denmark. They are expensive, not any good products and have a great share of the market. Like Microsoft. :)
There's a informative post about Arla at The Future Uncertain. More about the Arab boycot of companies dealing with Israel at Wikipedia.