Bromelain and Blood Pressure

Bromelain is the name given to a group of protein-digesting enzymes found exclusively in the fruit, stem or juice of pineapples. Supplementing with bromelain may help treat sinus infections, prevent swelling following a surgery or injury and increase the effectiveness of antibiotics used for urinary tract infections, according to the University of Michigan. Supplemental bromelain may cause potentially harmful side effects in people with high blood pressure. Do not use it before speaking to your doctor.

Effect on Blood Pressure

For the average adult, supplemental bromelain does not appear to have any effect on blood pressure, even with doses as high as 12 grams a day. However, people with high blood pressure have been advised to avoid bromelain since the late 1970s, because of a "Hawaii Medical Journal" study published in 1978 that suggested supplemental bromelain may increase the risk of elevated blood pressure and tachycardia -- an abnormally fast heart rate -- in hypertensive subjects. These side effects appeared to increase with higher doses of the enzyme. Further studies are needed to confirm that bromelain supplementation is dangerous for people with high blood pressure.

Interaction With Blood Pressure Medications

Bromelain should not be used by anyone taking an angiotensin-converting enzyme, also known as an ACE inhibitor medication. ACE inhibitors lower blood pressure and are typically prescribed for people with diabetes, hypertension, kidney disease or heart disease. Examples of ACE inhibitors include lisinopril, captopril, quinapril or benazepril. Supplemental bromelain may intensify the effect of these drugs and cause your blood pressure to fall below the recommended level, a condition known as hypotension. Hypotension can cause fainting, nausea, fatigue and dizziness.

Recommended Intake

If you are a healthy adult, supplementing with 750 to 1,000 milligrams of bromelain each day should not pose any health risks, though you should consult your doctor first. Individuals with blood pressure problems should not take the supplements, but can continue to consume fresh pineapple and pineapple juice, which contain a far lower concentration of bromelain than dietary supplements. Canned or cooked pineapple and processed pineapple juice have even less active bromelain since heat causes the enzyme to denature, or break down.

Additional Considerations

The U.S. Food and Drug Administration does not regulate bromelain supplements and their contents are not required to be verified by an outside party as being pure, free of contamination or effective. If you do not have problems with blood pressure and choose to take bromelain, select a brand whose manufacturers have voluntarily submitted their products to scrutiny by the nonprofit organization U.S. Pharmacopeia, advises ConsumerReports.org. You can identify these supplements by the "USP Verified" mark on their label.