Fresh pineapple is rich in bromelain, which is made up of a group of sulfur-containing proteolytic (protein-digesting) enzymes that not only aid digestion, but can effectively reduce inflammation and swelling, as in carpal tunnel syndrome; break down mucus in respiratory conditions, such as pneumonia and bronchitis; and have even been used experimentally as an anti-cancer agent. A variety of inflammatory agents are inhibited by the action of bromelain. In clinical human trials, bromelain has demonstrated significant anti-inflammatory effects, reducing swelling in inflammatory conditions such as acute sinusitis, sore throat, arthritis, and gout, and speeding recovery from injuries and surgery. To maximize bromelain's anti-inflammatory effects, pineapple should be eaten alone between meals or its enzymes will be used up in digesting food.
Pineapple is also an excellent source of the trace mineral manganese, an essential cofactor in a number of enzymes important in energy production and antioxidant defenses. For example, the key antioxidant enzyme superoxide dismutase requires manganese. Just one cup of fresh pineapple supplies 73.1 percent of the daily value of manganese.