Bromelain is a natural proteolytic, or protein-digesting enzyme, with side effects that can range from mild to severe. Reactions can include nausea, diarrhea, vomiting, and drowsiness, and some women have reported heavy menstrual bleeding. Other bromelain side effects include allergic reactions such as an increased heart rate, hives, and tightness in the throat. In rare instances, asthma symptoms have been documented as a side effect of bromelain. People who are at risk for experiencing bromelain side effects include those with known allergies to any of several things, including pineapple, wheat, bee stings, cypress pollen, birch pollen, kiwi, papaya, and grass.
Bromelain, which also is to blame for the sore mouth some people tend to develop after eating fresh pineapple, is extracted from the stem and juice of the common pineapple plant. Natives of Central and South America have known about the positive effects of pineapple and have used it medicinally for centuries. As well as using it to treat digestive disorders, pineapple has also been used to treat skin diseases and to promote healing, in general. Bromelain is now manufactured into capsule or pill form and sold over the counter in supermarkets, pharmacies and health food stores.
As a naturally occurring digestive enzyme, this readily available dietary supplement is purported to aid in the digestive process, easing the burden on the gastro-intestinal system. People with disorders related to gastro-intestinal inflammation may experience bromelain side effects and should not use it. Others find it helpful for nausea, heartburn, gastric reflux and other conditions related to digestion.
An anti-inflammatory agent, bromelain is widely used for arthritic pain and muscle soreness. In Germany, bromelain is used as standard protocol in after-surgery care. The anti-inflammatory properties of bromelain have also been shown to be helpful in reducing the painful symptoms of engorgement in nursing women. People who are not susceptible to the side effects of bromelain also find it helpful in boosting the human immune system, which makes it a promising complementary therapy to cancer treatments such as chemotherapy.
Bromelain is also known for its anticoagulant, or blood-thinning, properties. It is regarded as generally safe in moderation, but people taking any kind of blood-thinning medication should avoid bromelain to prevent side effects. Eating pineapple while taking blood thinners shouldn’t cause a problem, because bromelain is more concentrated in the pineapple stem and juice than in the fruit, but consulting a doctor can help address any concerns.