According to the report, about 25 percent of people can't taste propylthiouracil (PROP), a chemical that is similar to the bitter compounds found in cabbage, cauliflower, broccoli, coffee, tonic water, and dark beers. This means 75% of people detect unpleasant bitterness in these vegetables and beverages.
The bitter compounds in these foods are called glucosinolates. There are about 25 “bitterness genes”, according to scientists, which are also responsible for much of the nutritional value of these foods. Beyond the genetics, some people take kindly to certain types of bitterness and not others, matters of personal preferences.