Enzyme Supplement Safety and Efficacy

Dr. Zoltan P. RonaA Statement by Dr. Zoltan P. Rona, MD, BSc.

I am a duly licensed medical doctor in Ontario and have been in private medical practice for over 33 years. I specialize in complementary and integrative medicine and have written 11 books on the subject including “Vitamin D, The Sunshine Vitamin,” (Alive Books, 2010). Aside from my M.D. degree, I also have a Masters degree in Biochemistry and Clinical Nutrition. For a more detailed CV, see my web site (http://www.mydoctor.ca/drzoltanrona).

Enzyme supplements have been sold for over 50 years without incident. I have been writing about and prescribing various digestive enzyme supplements successfully for over 30 years. These over-the-counter products are manufactured by at least a dozen different companies and are sold in health food stores, supermarkets and pharmacies. Some of the manufacturers include NAKA, Biotics Research, Natural Factors, SISU, Platinum Naturals, Thorne Research, Metagenics, Advanced Orthomolecular Research, Integra, New Roots, and Professional Health.

I estimate that, in the past 30 years, I have prescribed enzymes to over 5,000 patients to use for anywhere between a few weeks to several years. About 20% of my patients have been taking digestive enzymes for over 10 years without any side effects.

While potential side effects have been documented with digestive enzymes, I have seen only minor nuisance side effects (gas, indigestion, constipation), which usually cleared with continued use of the product. Approximately 1% of my patients could not tolerate the enzymes and side effect symptoms disappeared upon stopping the product. Compared to most drugs on the market, my experience has been that digestive enzymes are significantly safer than most over-the-counter cough and cold remedies. In fact, while there are many documented deaths from over-the-counter Tylenol, I am unaware of any deaths from digestive enzymes. I refer you to a recent publication on natural supplement safety in the USA (Bronstein, et al) where they report zero deaths occurring with digestive enzyme use. See the reference at the end of this letter. Surely, if enzyme safety were an issue of any significance it would have been reported in this exhaustive study.

In general, I have found various types of digestive enzymes (pancreatin, serrapeptase, bromelain, papain, other plant enzymes, betaine and pepsin hydrochloride) to be extremely effective in reversing chronic gastrointestinal problems. These include diarrhea, gas, bloating, constipation, inflammatory bowel disease, food allergies, irritable bowel syndrome, micronutrient malabsorption, diverticulitis and diverticulosis.

In addition, I have found that digestive enzymes will reduce the severity of inflammation just about anywhere in the body, especially in the joints (arthritis), the tendons (tendonitis) and the bursa (bursitis). I also find them to be highly effective in speeding healing from just about any sports injury.

Some of my pancreatic cancer patients have also found that taking digestive enzymes reduces the severity of their pain and discomfort and allows them to eat a more complete diet, thereby prolonging their survival.

There is no truth that the taking of digestive enzymes shuts down the body’s own production of enzymes. This thinking is, at best, superstition and only applies to hormones in the body that have feedback inhibition mechanisms. The same concept does NOT apply to digestive enzymes. At least there is no supportive scientific research that confirms this line of thinking. In my clinical experience of over 33 years, I have never witnessed any patient, to whom I prescribed digestive enzymes, then become dependent on the enzymes from an external source. In fact, what I have witnessed was that after 3 – 6 months of enzyme supplementation, the patient’s digestion improved substantially enough to go without the enzymes. In other words, the digestive enzyme supplement healed the enzyme insufficiency of the body’s own production.

The evidence in support of digestive enzymes can be found in thousands of published studies and I include a few of these at the end of this letter (see below) in case you are interested in reading about them.


Bronstein AC, Spyker DA, Cantilena LR Jr, Green JL, Rumack BH, Dart RC. 2010 Annual Report of the American Association of Poison Control Centers’ National Poison Data System (NPDS): 28th Annual Report. The full text article is available for free download here.
Kane S, Goldberg MJ. Use of bromelain for mild ulcerative colitis. Ann Intern Med. 2000;132:680.
Medhekar R. The first quantitative evidence proving the efficacy of supplemental enzymes. Forsyth, MO: National Enzyme company; 2004.
Glade MJ, Kendra D, Kaminski MV, Jr. Improvement in protein utilization in nursing-home patients on tube feeding supplemented with an enzyme product derived from Aspergillus niger and bromelain. Nutrition 2001;17(4):348-50.
“European Review for Medical and Pharmacological Sciences”; Effect of beta-Glucan, Inositol and digestive enzymes in GI symptoms of patients with IBS; Ciacci C., et al; 2011
Digestive enzyme therapy for irritable bowel syndrome: http://www.livestrong.com/article/513243-digestive-enzyme-therapy-for-irritable-bowel-syndrome/#ixzz1iEzygXSt
Kolomoiets’ MIu, Antofiichuk MP. [The efficacy of the multienzyme preparation Wobe-Mugos E in lymphoproliferative diseases.] Lik Sprava. 1999 Jun;(4):150-4.
Gonzalez NJ, Isaacs LL. Evaluation of pancreatic proteolytic enzyme treatment of adenocarcinoma of the pancreas, with nutrition and detoxification support. Nutr Cancer. 1999;33:117-24.
Kamenicek V, Holan P, Franek P. Systemic enzyme therapy in the treatment and prevention of post-traumatic and postoperative swelling. Acta Chir Orthop Traumatol Cech. 2001;68(1):45-9.
Leipner J, Saller R. Systemic enzyme therapy in oncology: effect and mode of action. Drugs. 2000 Apr;59(4):769-80.
Stauder G, Ransberger K, Streichhan P, Van SW, Pollinger W. The use of hydrolytic enzymes as adjuvant therapy in AIDS/ARC/LAS patients. Biomed Pharmacother. 1988;42(1):31-4.
Stauder G. Pharmacological effects of oral enzyme combinations. Cas Lek Cesk. 1995 Oct 4;134(19):620-4.
Heyll U, Munnich U, Senger V. Proteolytic enzymes as an alternative in comparison with nonsteroidal anti-inflammatory drugs (NSAID) in the treatment of degenerative and inflammatory rheumatic disease: systematic review. Med Klin(Munich). 2003 Nov 15;98(11):609-15.
Klein G, Kullich W, Schnitker J, Schwann H. Efficacy and tolerance of an oral enzyme combination in painful osteoarthritis of the hip. A double-blind, randomised study comparing oral enzymes with non-steroidal anti-inflammatory drugs. Clin Exp Rheumatol. 2006 Jan;24(1):25-30.
Akhtar NM, Naseer R, Farooqi AZ, Aziz W, Nazir M. Oral enzyme combination versus diclofenac in the treatment of osteoarthritis of the knee: a double-blind prospective randomized study. Clin Rheumatol. 2004 Oct;23(5):410-5.
Leipner J, Iten F, Saller R. Therapy with proteolytic enzymes in rheumatic disorders. BioDrugs. 2001;15(12):779-89.

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