The role of diet and nutrition is very important in Crohn's disease and should be considered in four separate roles:
- As important add-on treatment to medical therapies for maintaining nutrition and correcting any nutritional deficiencies.
- Elemental diets as primary treatment for reducing disease activity.
- As maintenance therapy on a long-term basis in the case of severe intestinal failure or short-bowel syndrome.
- For reversing growth-failure in children.
Foods Important for protection protein. proteins are very important for growth in children and for repair of cells. Diarrhea can cause protein deficiency and so IBD patients may need more protein than the general population. patients might consider choosing fish and soy as primary protein sources. One study reported that a soy protein diet was particularly useful for patients who were intolerant to milk products. Oily fish, such as salmon and tuna, may be particularly beneficial in Crohn's disease. Other options are poultry and lean meats. Dried beans and legumes also provide protein.
Complex Carbohydrates. Complex carbohydrates found in whole grains, fruits, and vegetables should make up half of a patient's calories. patients should select complex carbohydrates, which are also a good source of fiber. Fresh fruit (such as apples, grapefruit, oranges, plums, blueberries, raspberries, and strawberries) might actually be specifically protective for IBD. (It should noted, however that simple sugars can increase inflammation, so patients should avoid dried fruits and high-sugar fruits, such as grapes, pineapple, and watermelon.)
It should be noted that high-fiber foods can cause gas, bloating, and pain, particularly in IBD patients. Commercial products (eg, Beano) are available that can reduce gas. Eating small, frequent meals can also help.
Fluids (non-caffeinated). Drinking plenty of water is particularly important. Caffeinated beverages should be avoided in general, although green tea has been reported to have some benefits for Crohn's disease.
Certain Oils. Omega-3 fatty acids are important compounds, particularly for Crohn's disease, found in fats. Sources include canola oil, soybeans, flaxseed, olive oil, and many nuts, seeds, and oily fish. See Role of Fats, below.
Liquid Supplements. Over-the-counter liquid diets, such as Ensure, Sustacal, and others that meet full nutritional needs and are absorbed in the upper intestine may be helpful for some Crohn's disease patients, but no studies have determined this.
potassium-rich Foods. Examples are potatoes, avocados, and bananas.
Foods Associated with Higher Risk for Symptoms Exclusion Diets. Exclusion diets are those that eliminate certain allergenic foods or those that might irritate the intestine. To determine these foods, patients use a so-called elimination/challenge approach. First they remove all suspect foods from their diet for two weeks and then reintroduce one food every three days. patients then watch for any symptoms that might indicate an allergic or irritant response, including gastrointestinal problems, headaches, and flushing. Some experts believe, however, that this approach is very difficult and studies are weak in confirming its value for maintaining remission.
Typical avoidance foods are as follows:
- Saturated fats, found in meat and dairy products. (It should be noted that certain fats, such as those found in oily fats, may be helpful.)
- Milk products. Some people with IBD are lactose intolerant (unable to digest the sugar lactose, found in milk products). Taking lactase tablets or specially prepared dairy products may help. (Many lactose-intolerant patients are still able to eat yogurt with active cultures, which may even be helpful for IBD.)
- Foods associated with inflammation (alcohol, simple sugars, and caffeine).
- Fruits may be protective, but patients should avoid dried fruits or high-sugar fruits, such as grapes, watermelon, or pineapple.
- products containing corn or gluten (those made from wheat, oats, barley, or triticale).
- Common allergenic foods, such as soy, eggs, peanuts, tomatoes.
- Foods that may irritated the intestine, particularly so-called Brassica vegetables (cabbage, Brussels sprouts, broccoli, cauliflower, kale).
Vitamins and Other Supplements Crohn's disease and surgical procedures that remove parts of the small intestine can inhibit absorption of vitamins, fats, and other important supplements. Taking certain supplements, such as fish oil, anti-oxidants, and mineral supplements may be beneficial for patients with Crohn's disease.
Vitamins. Deficiencies of vitamins A, C, E, B12, and folate (a B vitamin) may result from malabsorption. In general, vitamin supplements may be recommended for everyone with IBD, particularly for children to avoid growth retardation. Vitamins A, C, and E are antioxidants, which are scavengers of damaging particles in the body. Folic acid supplements are particularly important for patients who must restrict fresh fruits and vegetables and for those taking sulfasalazine. Folate deficiencies may contribute to the increased risk for colon cancer. Monthly injections of vitamin B-12 may be necessary. Vitamin D is necessary for bone protection. Because some vitamins, such as A and D, can be toxic high doses, patients should discuss specific dosages with their physicians.
Omega-3 Fatty Acids. The role of fats in inflammatory bowel disease is complex and not fully known. There is some evidence that Crohn's disease patients burn fat calories at a higher rate than the general population. IBD patients may be deficient in essential fatty acids, particularly omega-3 fatty acids (polyunsaturated fats found in oily fish and certain vegetable products, such as flaxseed and canola oils). Supplements containing omega-3 fatty acids may be particularly beneficial. (Such supplements may also be labeled as EpA-DHA, which are specific compounds found in fish oil.)
Mineral Supplements. Supplements of calcium, magnesium, zinc, selenium, and iron may be needed to offset deficiencies in patients with severe IBD.
- Calcium and magnesium are critical for health and strong bones.
- Selenium is a potent antioxidant.
- Zinc is important for wound healing, and deficiencies may promote fistulas in Crohn's disease.
- Iron supplements may be required for anemia. It should be noted that iron overdose is very dangerous. As few as three adult iron tablets can poison children, even fatally. No one, even adults, should take a double dose of iron if one is missed. A physician should advise patients carefully on correct dosage.
- polymeric diets (containing a balance of standard nutrients).
- Elemental diets (predigested nutrients that are absorbed in the first meter of the small intestine). Elemental diets are used less commonly.
Some studies have reported that an enteral elemental diet was as effective as corticosteroids in inducing remission. However, a major 2001 analysis did not confirm any advantages of enteral feedings over corticosteroids. Furthermore, it did not find any additional benefits from elemental diets compared to polymeric diets. Still, in a 2001 study of children with steroid-dependent Crohn's disease that was already in remission, elemental supplements allowed many of them to withdraw from the medication.
Total parenteral Nutrition. Total parenteral nutrition (TpN), or hyperalimentation, is the intravenous administration of nutrients through an indwelling catheter (tube). It has been used for very severe IBD when patients cannot tolerate any nutrition by mouth or with a feeding tube, and may even be useful as a primary therapy for Crohn's disease patients (although not for those with fistulas). It is usually administered in the hospital, although increasingly people are self-administering it at home. The procedure carries a risk for complications, some serious, including infection, blood clots, and liver failure.