Arabic?  An ethnic group associated with, of Levantine, originating in what is today the country of Lebanon, including those who had inhabited Mount Lebanon, prior to the creation of the modern Lebanese state.  Many factors of religion and the belief system can have a cause.  The best thing to do, is associate yourself with your friend more, to learn his/her cultural beliefs.  Otherwise; purchase or better,  make something learned of their culture.  This will bring a better understanding of one another.  Learning another's culture; Helps you understand yours too..

To be honest the best thing to drink is water.  Milk, provides all nutrients needed.  Anything else, can be placed as psychical, forming.