Quite apart from the caffeine, coffee contains caffeol, a volatile oil which
gives the unique taste and aroma. It is the caffeol which does more
damage to the stomach than the caffeine. In an interview published
in U.S. News & World Report, Dr. Joseph F. Montague, a leading
authority on intestinal disorders, made this statement about
cafeol "If you take a cup of coffee before you add milk or sugar and
let it stand a minute, you will see oil float to the surface and
swirl around. These oils are very irritating to the stomach and
duodenum, and to my mind are productive of more irritation, more
preulcerous conditions than anything else people eat. When a person
takes this coffee in the morning, he is pepped up. But in reality he
simply tightens the screw that holds the string of nervous tension."
U.S. News & World Report, February 26, 1968.