Quercetin, a member of the flavonoid family, gives many fruits and vegetables their vibrant color, and quercetin may help protect against cancer and heart disease, according to the University of Maryland Medical Center 123. Bromelain, on the other hand, is a mixture of enzymes found in pineapples, and is notably effective in reducing inflammation associated with injuries and infection, reports the UMMC. Because quercetin and bromelain may cause side effects or interact negatively with medications, you should not use these supplements without consulting your health care provider.
If you are experiencing serious medical symptoms, seek emergency treatment immediately.
Side Effects of Quercetin
Although quercetin is usually considered safe for consumption, you may experience side effects such as upset stomach and headache, states the UMMC. Additionally, some preliminary evidence exists that quercetin may generate a byproduct, which leads to loss of protein function in your body. Moreover, taking very high doses of quercetin -- greater than 1 gram per day -- may interfere with your kidney health. Therefore, the UMMC advises to take repeated breaks from taking quercetin. People suffering from kidney disease and pregnant and breastfeeding women should not take quercetin.
- Although quercetin is usually considered safe for consumption, you may experience side effects such as upset stomach and headache, states the UMMC.
- Therefore, the UMMC advises to take repeated breaks from taking quercetin.
Other Side Effects of Quercetin
How do I Take Bromelain?
Quercetin has been shown to cause changes in bacterial chromosomes during laboratory observations, according to an article published in the “Internet Journal of Medical Update” in 2007 3. However, the significance of this discovery for humans is still unclear. Pregnant women and nursing mothers should refrain from taking quercetin because of absence of availability of long-term safety data. Quercetin may also interfere with the body's absorption of cyclosporine, a drug, which decreases the activity of the immune system.
- Quercetin has been shown to cause changes in bacterial chromosomes during laboratory observations, according to an article published in the “Internet Journal of Medical Update” in 2007 3.
Side Effects of Bromelain
The UMMC says that bromelain is generally recommended for no more than 8 to10 days in a row. Bromelain can produce side effects such as excessive menstrual bleeding, vomiting, diarrhea and nausea. Individuals who are allergic to fennel, cypress pollen, papain, carrot, wheat, pineapple, celery or grass pollen may also be allergic to bromelain. People with liver or kidney disease, high blood pressure and bleeding disorders and pregnant women should not take bromelain, advises the UMMC. Bromelain may also increase the bleeding risk during and after surgery, therefore, you should stop taking bromelain two weeks before surgery.
- The UMMC says that bromelain is generally recommended for no more than 8 to10 days in a row.
- Bromelain may also increase the bleeding risk during and after surgery, therefore, you should stop taking bromelain two weeks before surgery.
Other Side Effects of Bromelain
Pineapple Allergy & Bromelain
Taking high doses of bromelain might elevate heart rate, according to a study published in the May 1978 issue of “Hawaii Medical Journal,”as reported in NYU Langone Medical Center 24. Bromelain may also slow down your body’s ability to clot blood, and could raise the risk of bleeding when taken with blood-thinning drugs such as clopidogrel, aspirin and warfarin. The UMMC notes that bromelain may increase the absorption of some antibiotics, especially tetracycline and amoxicillin. Furthermore, bromelain might increase the effect of sedative medications such as tricyclic antidepressants, barbiturates, anti-seizure medications and benzodiazepines. Therefore, check with your health care provider before consuming bromelain if you are taking any of these medications.
- Taking high doses of bromelain might elevate heart rate, according to a study published in the May 1978 issue of “Hawaii Medical Journal,”as reported in NYU Langone Medical Center 2.
- Bromelain may also slow down your body’s ability to clot blood, and could raise the risk of bleeding when taken with blood-thinning drugs such as clopidogrel, aspirin and warfarin.
How do I Take Bromelain?
Pineapple Allergy & Bromelain
Quercetin Dihydrate Side Effects
What Fruits Contain Protease Enzymes?
Will Coenzyme Q10 Elevate Liver Enzymes?
Resveratrol Recommended Dosage
How to Block TNF With Herbal Remedies
Bromelain for Weight Loss
Foods High in Bromelain
Quercetin & Nettles for Allergy Relief
- University of Maryland Medical Center: Quercetin
- University of Maryland Medical Center: Bromelain
- Internet Journal of Medical Update: Quercetin: A Versatile Flavonoid
- NYU Langone Medical Center: Bromelain
- Ameye LG, Chee WS. Osteoarthritis and nutrition. From nutraceuticals to functional foods: a systematic review of the scientific evidence. Arthritis Res Ther. 2006;8(4): R127.
- Baez R, Lopes MT, Salas CE, Hernandez M. In vivo antitumoral activity of stem pineapple (Ananas comosus) bromelain. Planta Med. 2007 Oct;73(13):1377-83.
- Braun JM, Schneider B, Beuth HJ. Therapeutic use, efficiency and safety of the proteolytic pineapple enzyme Bromelain-POS in children with acute sinusitis in Germany. In Vivo. 2005;19:417–421.
- Brien S, Lewith G, Walker A, Hicks SM, Middleton D. Bromelain as a Treatment for Osteoarthritis: a Review of Clinical Studies. Evid Based Complement Alternat Med. 2004 Dec;1(3):251-257.
- Brien S1, Lewith G, Walker AF, Middleton R, Prescott P, Bundy R. Bromelain as an adjunctive treatment for moderate-to-severe osteoarthritis of the knee: a randomized placebo-controlled pilot study. QJM. 2006 Dec;99(12):841-50.
- Buttner L, et al. Efficacy and tolerability of bromelain in patients with chronic rhinosinusitis—a pilot study. B-ENT. 2013;9(3):217-25.
- Chobotova K1, Vernallis AB, Majid FA. Bromelain's activity and potential as an anti-cancer agent: Current evidence and perspectives. Cancer Lett. 2010 Apr 28;290(2):148-56.
- Dhandayuthapani S1, Perez HD, Paroulek A, Chinnakkannu P, Kandalam U, Jaffe M, Rathinavelu A. Bromelain-induced apoptosis in GI-101A breast cancer cells. J Med Food. 2012 Apr;15(4):344-9.
- Guo R, Canter PH, Ernst E. Herbal medicines for the treatment of rhinosinusitis: a systematic review. Otolaryngol Head Neck Surg. 2006 Oct;135(4):496-506.
- Hale LP1, Greer PK, Trinh CT, Gottfried MR. Treatment with oral bromelain decreases colonic inflammation in the IL-10-deficient murine model of inflammatory bowel disease. Clin Immunol. 2005 Aug;116(2):135-42.
- Memorial Sloan Kettering Cancer Center. Bromelain.
- National Center for Complementary and Integrative Health. Bromelain.
- Onken JE, Greer PK, Calingart B, Hale LP. Bromelain treatment decreases secretion of pro-inflammatory cytokines and chemokines by colon biopsies in vitro. Clin Immunol. 2008 Mar;126(3):345-52. Epub 2007 Dec 21.
- Pavan R1, Jain S, Shraddha, Kumar A. Properties and therapeutic application of bromelain: a review. Biotechnol Res Int. 2012;2012:976203.
- Rathnavelu Vidhya, et al. Potential role of bromelain in clinical and therapeutic applications. Biomed Rep. 2016 Sep; 5(3): 283–288.
- Rosenberg L, Shoham Y, Krieger Y, et al. Minimally invasive burn care: a review of seven clinical studies of rapid and selective debridement using a bromelain-based debriding enzyme (Nexobrid). Ann Burns Fire Disasters. 2015 Dec 31;28(4):264-274.
- Ryan RE. A double-blind clinical evaluation of bromelains in the treatment of acute sinusitis. Headache. 1967;7:13-17.
- Secor ER Jr1, Shah SJ, Guernsey LA, Schramm CM, Thrall RS. Bromelain limits airway inflammation in an ovalbumin-induced murine model of established asthma. Altern Ther Health Med. 2012 Sep-Oct;18(5):9-17.
- Tejpal Singh, Vinayak More, Umayra Fatima, Tanveer Karpe, Mohammed A. Aleem, J. Prameela. Effect of proteolytic enzyme bromelain on pain and swelling after removal of third molars. J Int Soc Prev Community Dent. 2016 Dec; 6(Suppl 3): S197–S204.
- Walker AF1, Bundy R, Hicks SM, Middleton RW. Bromelain reduces mild acute knee pain and improves well-being in a dose-dependent fashion in an open study of otherwise healthy adults. Phytomedicine. 2002 Dec;9(8):681-6.
Mala Srivastava covers health and business for several online publications. She holds a Master of Science in microbiology from India's HNB Garhwal University and a Master of Pharmaceutical Business Management from ICFAI University.