enzyme therapy
What Is It?
How Does It Work?
What You Can Expect
Health Benefits
How To Choose a Practitioner
Evidence Based Rating Scale

What Is It?

Enzyme therapy involves using an array of enzymes, or complex proteins from plants and animals, in supplement form to aid digestion and treat a wide variety of maladies thought to stem from nutritional problems. These enzyme supplements are believed to bolster the thousands of natural enzymes produced by the human body (and also obtained from foods), which not only fuel digestion but also aid hundreds of other processes essential for life.

Many of the supplements used in enzyme therapy are animal- or plant-derived digestive enzymes. Animal enzymes that enhance digestion are sometimes referred to as pancreatic enzymes, because many of them are released from the pancreas, the spongy, tongue-shaped gland that sits under the stomach. (The pancreas also produces the hormone insulin, essential for keeping blood sugar levels in check.) Pancreatic enzymes spill into the bowel, fueling the breakdown of proteins, carbohydrates, and fats into essential nutrients that can be readily absorbed by the body.

Other digestive enzymes are released from the salivary glands, the stomach, and the walls of the small intestine. If you chew a cracker and hold it in your mouth, for example, enzymes in saliva break the carbohydrates into simpler sugars, and the salty starches soon begin to taste sweet.

Plant enzymes are also essential for proper digestion. Cellulase (many enzymes end with the letters "-ase"), for instance, helps to break down fiber. Humans do not make this enzyme, so it must be obtained from fruits and vegetables, or from supplements. Like their animal-derived counterparts, other plant enzymes stimulate digestion of proteins (proteases), carbohydrates (amylases), and fats (lipases) in the stomach and bowel. Common plant-based digestive enzymes include papain, which comes from papayas; bromelain, from pineapples; and a host of enzymes made through fermentation by the fungus Aspergillus.

Some nutritionally oriented doctors prefer plant-based digestive enzymes to animal-based ones, because they feel that plants provide a wider range of active enzymes. However, plant and animal products are both used in enzyme therapy, together or alone.

In addition to digestive enzymes, nondigestive enzyme products are sold in health-food stores to boost energy, fight inflammation, and enhance antioxidant activity. Examples include superoxide dismutase (SOD), glutathione peroxidase, and catalase (CAT). Some experts advise, however, that these so-called metabolic or antioxidant enzyme pills are not worth the money because they are broken down and inactivated once they enter the digestive tract.

Many mainstream physicians contend that most of us get or produce all the enzymes we need naturally or through diet. According to these doctors, we do not need extra enzymes in supplement form unless a specific enzyme defect is present. Proponents of enzyme therapy, on the other hand, believe that just about everyone can benefit from extra enzymes because of hidden deficits caused by poor diet, illness and advancing age. It has long been known, for example, that cooking foods at temperatures above 118°F, well below the threshold of a gentle simmer, destroys many of the enzymes found in plant and animal foods.

To make up for these missing nutrients, Dr. Edward Howell, who pioneered enzyme therapy in the United States during the 1920s, advocated eating a diet containing uncooked vegetables and raw meats to replenish missing enzymes. Many practitioners today likewise recommend a diet rich in whole, raw foods (usually minus the meat, for safety reasons and other concerns) as a complement to enzyme therapy and to counter the modern fast-food diet.

How Does It Work?

Enzyme therapy is based in part on the simple notion that if something is missing, replacing it with a suitable substitute fixes the problem. If you are lactose intolerant, for example, your body does not produce enough lactase, the enzyme that breaks down milk sugars. Cramping and diarrhea result as dairy products pass through your bowel undigested. Taking lactase supplements with meals can make these foods tolerable by acting as "hired hands," doing the work that your body cannot.

More serious body-wide problems can arise with certain uncommon genetic diseases, such as cystic fibrosis, which are caused by inherited enzyme deficiencies. For this reason, conventional doctors routinely prescribe enzyme supplements when a specific genetic defect is uncovered.

Advocates of enzyme therapy argue that since many people are deficient in important enzymes, most of us can benefit from more of them. Additional digestive enzymes, they say, help to protect the body against a wide range of ailments by ensuring optimal digestion. Foods are thereby completely broken down into vital nutrients that can be readily absorbed into the bloodstream, providing essential vitamins and minerals to tissues throughout the body. By promoting digestion, enzymes may also accelerate the passage of food through the stomach and digestive tract, reducing acid retention, heartburn and irritation.

Enthusiasts of enzyme therapy also claim that it has additional beneficial effects on the body. For example, in some people, poorly or incompletely digested food may give rise to food allergies or sensitivity reactions to certain chemical components in foods. Supplemental digestive enzymes may reduce such reactions. In addition, by reducing the workload on the pancreas and other organs, enzyme therapy is said to free up enzymes to do additional work in the body. These enzymes, some believe, could help clean the bloodstream of stray virus protein, undigested food proteins that have leaked through the gut lining, and other internally generated toxins, thereby boosting immunity, quelling inflammation and preventing illness. There are no rigorous studies, however, to back up most of these claims.

What You Can Expect

At your first visit, the doctor will likely ask about any digestive complaints or other problems you're having. If the doctor is nutritionally oriented, you may be given general supplement recommendations regarding digestive support based on your clinical history. In some cases, your blood, urine and fecal content may be analyzed before specific therapies are suggested. In addition, a test may be performed in which you swallow a capsule to check the acid production in your stomach. Lab tests may also be done to check for specific enzyme deficiencies.

Test results are generally available within several days to a few weeks, and a follow-up visit will be scheduled. If a specific defect is uncovered, a particular enzyme may be suggested. Some, such as Lactaid for lactose intolerance, are readily available over-the-counter; other more specialized enzymes (for inherited defects, for example) are usually available only by prescription. More often, however, an array of enzymes or an enzyme blend will be recommended. Readily available at health-food stores and other outlets, these enzymes are most often taken as capsules, tablets, or powders. Enzymes are also available as creams and lotions, and some doctors deliver them as enemas or by injection. Your doctor may also suggest additional herbs or nutritional supplements, as well as ways to improve your overall diet.

For most digestive complaints, doctors typically recommend that enzymes be taken several times a day with meals. Because a large number of pills may be involved, it may be more convenient to buy powders or to open capsules and sprinkle the contents into smoothies or juices, or over food. (Enteric-coated tablets should not be chewed, since the protective coating is designed to prevent breakdown of the enzyme in the acid environment of the stomach.) For nondigestive complaints, some doctors advise taking enzymes between meals to prevent competition with foods and to allow for maximum absorption into the bloodstream.

Benefits may be felt within hours to a week for simple digestive complaints. More serious and chronic ailments may take weeks to months for full effects to be felt. If you don't notice any improvement after a month or so, check with your practitioner: Enzyme therapy may not be right for you. Depending on your condition, your doctor will likely schedule periodic follow-up visits every few weeks to months to see how you are progressing.

Health Benefits

Studies have confirmed that enzymes are effective for a number of medical conditions. For example, doctors prescribe pancreatin, a blend of pancreatic enzymes derived from pigs, to improve absorption of nutrients in people with cystic fibrosis or diseases of the pancreas. (1) Other enzymes are prescribed for rare, inherited enzyme disorders, such as Fabry's disease, Pompe disease, and Gaucher's disease, which typically appear during childhood. (2) Enzymes are also often helpful for long-term celiac disease, an allergic reaction to the gluten in wheat and other foods. (3)

Anecdotal evidence also suggests that enzymes are helpful for a variety of digestive ailments, including heartburn, bloating, and the chronic indigestion that comes with aging. Inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, as well as irritable bowel syndrome, may also improve with enzymes. And everyday complaints can be helped as well: If you're prone to embarrassing outbursts of gas, for example, you may find relief with the enzyme product Beano; if you're lactose intolerant, Lactaid may help. Even in the absence of symptoms, some practitioners recommend routine use of enzymes for just about everyone to maintain peak digestive health.

Enzymes are also used for a wide range of nondigestive ailments. The pineapple enzyme bromelain, for instance, is an effective remedy for bruises. (4) Skin conditions such as rosacea may also benefit from enzymes, as may more generalized complaints such as candida (yeast) overgrowth syndrome. (5, 6) Some practitioners claim that enzyme therapy can slow the progressive nerve damage of multiple sclerosis, although one recent study suggested that an excess of certain enzymes that digest proteins (proteases) may actually contribute to its onset.

Although proof is lacking, enzyme therapy is advocated or being studied for many more ailments, including allergies, infections, arthritis, hepatitis C, cataracts, and shingles.

Perhaps most controversial is the use of enzyme therapy to treat cancer. Pancreatic enzymes were first given to cancer patients by British embryologist John Beard in the 1890s, around the time that Madame Curie was pioneering the use of radiation treatments. Today, some practitioners follow European protocols that employ high-dose enzyme therapy as an adjunctive, or supportive, treatment for cancers of the pancreas, colon, lung, and other organs.

Unfortunately, definitive scientific studies on the benefit of enzyme therapy in cancer treatment are currently lacking. A rigorous study is under way to test enzymes against pancreatic cancer, and the Food and Drug Administration (FDA) has approved early studies of a highly concentrated blend of pancreatic enzymes called Wobe-Mugos against multiple myeloma, an uncommon malignancy of the immune system. Additionally, a few small studies from the Ukraine and Europe suggest that enzymes may help ease some of the side effects of chemotherapy or radiation treatments. (7) Indeed, by helping to improve digestion in an otherwise weakened system, enzymes may be a sensible nutritional complement for those undergoing such standard cancer therapies. Until benefits are proven, however, enzyme therapy should not be used as a substitute for more conventional, and potentially lifesaving, cancer treatments.

How To Choose a Practitioner

By some estimates, more than 2,000 practitioners in the United States are skilled in the use of enzyme therapy, and the numbers are growing. Holistic medical doctors, naturopathic physicians, osteopathic physicians, chiropractors, clinical nutritionists, and others may all include enzymes in their practices. However, because most enzymes are sold as supplements and are readily available over-the-counter, they may be self-prescribed and used by anyone. As with other dietary supplements, the quality, potency, and effectiveness of OTC enzyme products may vary. If you have a specific health concern, seek advice on reasonable product choices from an expert on dietary supplements.

Because enzyme therapy is practiced by a range of health professionals who can prescribe dietary measures and nondrug therapies for health problems, there is no professional organization to license or certify enzyme therapists. As with any other type of treatment, seek referrals from conventional health-care practitioners and others whom you trust, and be sure to research a practitioner’s training and experience in enzyme therapy as part of their clinical practice history.


  • Enzymes have a good safety record. Side effects tend to be minimal, although diarrhea, cramping, or stomach upset may occur when starting therapy. Unlike many vitamins and minerals, it's difficult to overdose on enzymes; they are eliminated from the body fairly rapidly. However, some patients with very sensitive digestive systems can have problems with enzyme therapy. See your doctor if stomach or intestinal distress is severe or other symptoms develop.
  • Sneezing, a skin rash, or other symptoms of an allergic reaction can occur in sensitive individuals. Don't use a particular enzyme if you know you are allergic to its source, such as bromelain (from pineapples), papain (from papayas), or animal enzymes (from pigs, cows, or oxen). Stop taking the supplement if an unexpected reaction occurs.
  • If you have diabetes, consult your doctor before taking enzymes. Some can contribute to swings in blood sugar levels or interfere with drugs such as miglitol (Glyset).
  • Enzymes, like many drugs and dietary supplements, have not been well studied in pregnant or breast-feeding women. Let your doctor know if you are pregnant or plan to become pregnant.
  • Wait at least two hours after taking digestive enzymes before taking antacids, since the antacids may hinder the effects of certain enzymes.
  • Some sources recommend that older people with poor digestion or absorption take a digestive enzyme product containing pepsin, a protein-dissolving enzyme, and betaine hydrochloride, which adds more stomach acid to the digestive process. Check with your doctor first: Betaine hydrochloride is not safe if you have peptic ulcers or other conditions that cause excess acidity.
  • If you have liver disease, talk to your doctor before taking enzymes.
  • If you are scheduled for surgery, on anticoagulant medications such as warfarin, or have hemophilia, let your doctor know if you are taking enzymes. Some may affect blood clotting.

Evidence Based Rating Scale

The Evidence Based Rating Scale is a tool that helps consumers translate the findings of medical research studies with what our clinical advisors have found to be efficacious in their personal practice. This tool is meant to simplify which supplements and therapies demonstrate promise in the treatment of certain conditions. This scale does not take into account any possible interactions with any medication/ condition/ or therapy which you may be currently undertaking. It is therefore advisable to ask your doctor before starting any new treatment regimen.



















Date Published: 04/19/2005

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