Existing dietary guidelines for Crohn s disease and ulcerative colitis

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1 For reprint orders, please contact Existing dietary guidelines for Crohn s disease and ulcerative colitis Expert Rev. Gastroenterol. Hepatol. 5(3), (2011) Amy C Brown 1, S Devi Rampertab 2 and Gerard E Mullin 3 1 Department of Complementary & Alternative Medicine, John A Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo Street, MEB 223, Honolulu, HI 96813, USA 2 Division of Gastroenterology, Penn State Hershey Medical Center, PA, USA 3 Johns Hopkins School of Medicine, The Johns Hopkins Hospital, MD, USA Author for correspondence: Tel.: amybrown@hawaii.edu Patients with inflammatory bowel disease (IBD) often question their doctors about diet. The objectives of this article are to provide clinicians with existing dietary advice by presenting the dietary information proposed by medical societies in the form of clinical practice guidelines as it relates to IBD; listing dietary guidelines from patient-centered IBD-related organizations; and creating a new global practice guideline that attempts to consolidate the existing information regarding diet and IBD. The dietary suggestions derived from sources found in this article include nutritional deficiency screening, avoiding foods that worsen symptoms, eating smaller meals at more frequent intervals, drinking adequate fluids, avoiding caffeine and alcohol, taking vitamin/mineral supplementation, eliminating dairy if lactose intolerant, limiting excess fat, reducing carbohydrates and reducing high-fiber foods during flares. Mixed advice exists regarding probiotics. Enteral nutrition is recommended for Crohn s disease patients in Japan, which differs from practices in the USA. Keywords: Crohn s disease diet dietary supplements enteral nutrition inflammatory bowel disease nutrition parenteral nutrition ulcerative colitis Although physicians are not always taught information about diet and inflammatory bowel disease (IBD) in their training or through their professional associations, registered dietitians may also not be adequately prepared to present dietary information to patients with IBD. Based on our previous review of the literature on diet and Crohn s disease (CD), it appears that a large gap exists in translating research-based dietary knowledge to clinical practice for the IBD population [1]. Creating evidence-based dietary recommendations for people with IBD is an un addressed need. These patients need up-to-date dietary clinical practice guidelines that will, if possible, best serve to reduce the risk of nutritional deficiency and possibly reduce their symptoms. The current state of the art is that various clinical practice guidelines for IBD patients exist, but many are sparse on dietary recommendations, and vary by origin. The objectives of this article are to: Collectively present the dietary information relating to IBD in the form of clinical practice guidelines proposed by medical societies; List the informal dietary guidelines suggested by patient-centered IBD-related associations; Create a new global practice guideline that incorporates the current clinical practice guidelines and informal dietary recommendations into one consolidated set of guidelines; Comment on existing nutrition guidelines for IBD and recommend future research. Clinical practice guidelines The current recommendations of the American Dietetic Association (ADA), clinical practice guidelines from selected medical organizations and a few informal dietary recommendations are now briefly summarized. The American Dietetic Association The ADA [101] is the world s largest organization of food and nutrition professionals, and their online Nutrition Care Manual (available by subscription) lists the majority of diets recommended for various medical conditions [102]. Only general guidelines are provided for IBD listed in Box 1, with an accompanying table of recommended foods (Table 1) and foods that are not recommended (Table 2). The American College of Gastroenterology The American Journal of Gastroenterology published the American College of Gastroenterology /EGH Expert Reviews Ltd ISSN

2 Brown, Rampertab & Mullin Box 1. General inflammatory bowel disease guidelines from the American Dietetic Association. Eat small meals or snacks every 3 or 4 h Use low-fiber foods when you have symptoms (recommended foods chart: Table 1). You can slowly reintroduce small amounts of whole-grain foods and higher-fiber fruits and vegetables one at a time when symptoms improve Drink enough fluids (at least eight cups each day) to avoid dehydration Eat foods with added probiotics and prebiotics Use a multivitamin During periods when you don t have symptoms, include whole grains and a variety of fruits and vegetables in your eating plan. Start new foods one at a time, in small amounts 2010 American Dietetic Association. Reprinted with permission from [101]. (ACG) Practice Guidelines for CD [2] and ulcerative colitis (UC) [3]. Crohn s disease The only mention of nutrition for patients with CD is no placebo-controlled trials of nutritional therapy for active CD have been performed. They report that corticosteroids are more effective than enteral nutrition to induce remission in active CD patients, but that more than 50% of corticosteroid acute users become steroid dependent or steroid resistant. It is also mentioned that no difference in efficacy exists between elemental and polymeric diets, and the only appropriate use of enteral diets is as an adjunctive therapy to support a patient s nutrition [2]. Ulcerative colitis The dietary information for patients with UC is more sparse. It states, with the exception of patients with significant nutrition depletion, total parenteral nutrition showed no benefit, and may even deprive colonic enterocytes of short-chain fatty acids [3]. The online ACG consumer guide information sheets [103] provide more information on diet and suggest: Lactose-intolerant individuals should avoid milk or milk products or use those to which lactase enzyme has been added; A low-roughage diet is recommended for those experiencing diarrhea after meals; Patients can often eat a reasonably unrestricted diet. World Gastroenterology Organization practice guidelines Compared with other clinical practice guidelines, those from the World Gastroenterology Organization (WGO) provide the most comprehensive dietary advice to IBD patients [4]. Diet and lifestyle considerations are part of the WGO global guidelines [4]. Although they state that the impact of diet is poorly understood, they add that dietary changes may help reduce symptoms in CD and UC. Their guidelines, provided in Box 2, Table 1. American Dietetic Association recommended foods for inflammatory bowel disease. Food group Recommended foods Notes Milk and dairy products Buttermilk Evaporated, skimmed, powdered or low-fat milk Yogurt Cheeses (low-fat) Ice cream (low-fat) Sherbet Choose lactose-free products if you have lactose intolerance. Lactose intolerance causes symptoms after drinking regular milk or eating foods from milk. Symptoms include diarrhea, nausea, stomach pain and bloating Choose yogurt with live, active cultures (see food label) Meats and other protein foods Tender, well-cooked meats, poultry, fish, eggs and soy prepared without added fat Smooth nut butter Grains Vegetables Fruits Fats and oils Bread, bagels, rolls, crackers, cereals and pasta made from white or refined flour Most well-cooked vegetables without seeds Potatoes without skin Lettuce Strained vegetable juice Fruit juice without pulp (except prune juice) Ripe banana or melons Most canned, soft fruits Peeled apple Choose grain foods with less than 2 g of fiber per serving (see food label) See Table 2 for vegetables to avoid if you have diarrhea or abdominal pain Choose canned fruit in juice or light syrup. Heavy syrup has lots of sugar, which may make diarrhea worse. See Table 2 for foods to avoid if you have diarrhea or abdominal pain Limit fats and oils to less than eight teaspoons per day Beverages Water Decaffeinated coffee Caffeine-free tea Soft drinks without caffeine Rehydration beverages 2010 American Dietetic Association. Reprinted with permission from [101]. Drinking beverages with sugar or corn syrup may make diarrhea worse. Very sweet juices may also have this effect 412 Expert Rev. Gastroenterol. Hepatol. 5(3), (2011)

3 Existing dietary guidelines for Crohn s disease & ulcerative colitis Review focus on the reduction of symptoms (CD and UC), reduction of inflammation (CD), probiotics and supplements. The American Society for Parenteral & Enteral Nutrition The American Society for Parenteral and Enteral Nutrition (ASPEN) guidelines, divided by adult and pediatric patients in Box 3, suggest that all IBD patients should receive nutrition screening to determine which patients require formal nutrition intervention [5]. The European Society for Clinical Nutrition & Metabolism In 2006, the European Society for Parenteral and Enteral Nutrition (ESPEN) published enteral nutrition guidelines for IBD patients [6]. Van Gossum et al. stated that malnutrition occurs in 20 85% of CD patients, and the highest risk group is patients with the disease in their small intestines [7]. Selected dietary guidelines for enteral and parenteral nutrition from both publications are highlighted in Box 4. The Japanese Society for Pediatric Gastroenterology, Hepatology & Nutrition The authors of Guidelines for the treatment of CD in children, published in Pediatrics International, the official journal of the Japan Pediatric Society, provide their guidelines in Box 5 [8]. Table 2. American Dietetic Association foods to avoid for inflammatory bowel disease. Food group Milk and dairy products Meats and other protein foods Grains Vegetables Fruits Fats and oils Beverages Other Foods to avoid Whole milk, half-and-half, cream, sour cream Yogurt with berries, orange or lemon rind, or nuts Ice cream (unless low-fat or nonfat) Fried meats, including sausage and bacon Luncheon meats, such as bologna or salami Hot dogs Tough or chewy cuts of meat Fried eggs All dried beans, peas and nuts Chunky nut butters Whole-wheat or whole-grain breads, rolls, crackers or pasta Brown rice and wild rice Cereals made from whole grain Any grain foods made with seeds or nuts Beets, broccoli, Brussels sprouts, cabbage, sauerkraut, cauliflower, corn, greens (spinach, mustard, turnip and collards), lima beans, mushrooms, okra, onions, parsnips, peppers, potato skins and winter squash All raw fruits except peeled apples, ripe bananas and melon Canned berries, canned cherries Dried fruits, including raisins Prune juice Do not have more than eight teaspoons a day Beverages with caffeine, such as coffee, tea, cola and some sport drinks Alcoholic drinks Avoid sweet fruit juices and soft drinks or other beverages made with sugar or corn syrup if they make diarrhea worse Sugar alcohols (sorbitol, mannitol and xylitol) cause diarrhea in some people. These ingredients are often found in sugarless gums and candies, and some medications 2010 American Dietetic Association. Reprinted with permission from [101]. Informal dietary recommendation Several informal sources of dietary information for patients with IBD exist through the Crohn s & Colitis Foundation of America, The National Digestive Diseases Information Clearinghouse and Medline Plus. These public recommendations are now briefly provided in the following sections. Crohn s & Colitis Foundation of America The leading IBD nonprofit association in the USA suggests on their website that there is no single diet for everyone with IBD, and that dietary recommendations must be individualized [104]. However, they add that, what you eat may go a long way toward reducing symptoms and promoting healing. The Specific Carbohydrate Diet, popularized in Elaine Gottschall s lay book, Breaking the Vicious Cycle, is mentioned as being only supported by patient testimonials, but bottom line, it may be worth a try. Patients are recommended to limit their salt intake during corticosteroid treatment because salt worsens fluid retention. If there is a stricture, Box 6 provides suggestions to avoid cramping or contractions. The National Digestive Diseases Information Clearinghouse The National Digestive Diseases Information Clearinghouse, a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIH) lists no recommendations concerning diet for UC, but Box 7 lists suggestions for those with CD [105]. Medline Plus The website providing information from the National Library of Medicine, the NIH and other government agencies and healthrelated organizations provides more detailed information for IBD patients (Box 8) [106,107]. Global IBD dietary clinical practice guideline Many of the aforementioned dietary recommendations have identical or similar content, with some degree of variation. In order to consolidate the information into a concise summary, Table 3 was created by the authors to provide a summary of existing guidelines. This is an educated summary of existing guidelines 413

4 Brown, Rampertab & Mullin Box 2. World Gastroenterology Organization clinical practice guidelines for inflammatory bowel disease concerning diet. During disease activity, decrease the amount of fiber Dairy products can be maintained unless not tolerated A high-residue diet may be indicated in cases of ulcerative proctitis (disease limited to rectum where constipation is more of a problem) Limited data suggest that reducing dietary fermentable oligosaccharides, disaccharides and monosaccharides, and polyols may reduce symptoms of IBD Diet and lifestyle considerations may reduce inflammation in CD, specifically: A liquid diet, predigested formula or nothing by mouth may reduce obstructive symptoms An exclusive enteral diet can settle inflammatory disease, especially in children Probiotics: IBD may be caused or aggravated by alterations in gut flora There is no evidence that probiotics are effective in either UC or CD; however: Escherichia coli Nissle 1917 is not inferior to 5-aminosalicylic acid VSL#3 (combination of eight bacterial strains) reduced flares of pouchitis (a post-ileoanal pouch procedure for UC) Supplements: Nutritional supplementation for those with malnutrition or during periods of reduced oral intake Vitamin/mineral supplementation for all Vitamin B 12 and vitamin D for those that who are deficient Steroid users should receive calcium and vitamin D supplementation Chronic iron-deficiency anemia should be treated with parenteral iron if oral iron is not tolerated CD: Crohn s disease; IBD: Inflammatory bowel disease; UC: Ulcerative colitis. Adapted from [4]. and no attempt has been made to explore the scientific basis for these recommendations. Commentary on existing IBD dietary guidelines Overall, the subject of diet and IBD embodies both nutrient deficiencies, as well as the role diet may play in reducing IBD symptoms. The former has more concrete data, whereas the latter has not been well investigated. The literature becomes difficult to decipher at times because nutritional therapy, a broad term covering all types of nutrition, is often used in the medical literature to define enteral and/or parenteral nutrition in relationship to IBD, and rarely describes an actual oral diet. The topics of nutritional deficiency screening, diet and enteral and/or parenteral nutrition are now briefly discussed in light of the aforementioned existing dietary guidelines for patients with IBD. Nutritional deficiency screening Nutritional deficiency for patients with IBD is well described in the literature, but only the ESPEN has recommended nutritional deficiency screening in this patient population [7]. A diseased GI tract can potentially compromise nutrient status, especially with regards to nutrient absorption, healing and/or growth in children. Primary problems related to CD include mal absorption, malnutrition, Box 3. American Society for Parenteral and Enteral Nutrition clinical practice guidelines for inflammatory bowel disease concerning diet. Adult practice guidelines for IBD from ASPEN include [8]: Enteral nutrition should be used in CD patients requiring specialized nutrition support Parenteral nutrition should be reserved for those patients with IBD in whom enteral nutrition is not tolerated Fistula-associated CD a brief course of bowel rest and parenteral nutrition is recommended Perioperative specialized nutrition support is indicated for those who are severely malnourished and for those in whom surgery can be safely postponed Specialized nutrition support and bowel rest should not be used as primary therapies for either UC or CD Pediatric practice guidelines for IBD patients provided by ASPEN include: Enteral nutrition should be given to children with growth retardation to help induce a growth spurt Enteral nutrition should be used as an adjunct to medical therapy in those who are unable to maintain their nutrition status through oral intake Parenteral nutrition should be used in children who are unable to maintain normal growth and development on enteral nutrition or a standard diet ASPEN: American Society for Parenteral and Enteral Nutrition; CD: Crohn s disease; IBD: Inflammatory bowel disease; UC: Ulcerative colitis. Adapted from [5]. 414 Expert Rev. Gastroenterol. Hepatol. 5(3), (2011)

5 Existing dietary guidelines for Crohn s disease & ulcerative colitis Review Box 4. The European Society for Clinical Nutrition and Metabolism clinical practice guidelines for inflammatory bowel disease concerning diet. Crohn s disease: Enteral nutrition is indicated for the prevention and treatment of undernutrition, improving growth in children, quality-of-life improvements, acute-phase therapy, perioperative nutrition and maintenance of remission in chronic active disease Enteral nutrition is the sole therapy in adults during the acute phase when corticosteroid treatment is not feasible For enteral therapy, use oral supplements up to 600 kcal/day with food intake, and then tube feeding if higher intakes are necessary. Continuous tube feeding is better than bolus, owing to a lower complication rate Whole proteins are preferred as free amino acid- or peptide-based formulas are not recommended Parenteral nutrition is usually combined with oral/enteral food unless there is continuing intra-abdominal sepsis or perforation Undernourished CD patients may benefit from parenteral nutrition Despite encouraging experimental data, insufficient data exist to recommend glutamine, n-3 fatty acids or other pharmaconutrients Vitamin B 12 deficiencies are well documented, especially if the distal ileum is affected by CD or resectioned. In these patients, serum B 12 and folate should be measured annually Correct nutrient deficiencies with vitamin/mineral supplementation Ulcerative colitis: Unlike CD, both enteral and parenteral nutrition do not serve as primary therapies in UC, where nutritional deficiencies are not as common compared with CD. Enteral nutrition is only for patients with undernutrition or inadequate intake Parenteral nutrition should only be used in those with UC who are malnourished or at risk of becoming malnourished before or after surgery because they cannot tolerate food or an enteral feed Bowel rest should not be provided through the use of parenteral nutrition during acute inflammatory periods Parenteral and enteral nutrition are not recommended for the maintenance of remission Iron-deficient anemia due to blood loss occurs in 80% of UC patients Correct nutrient deficiencies with vitamin/mineral supplementation CD: Crohn s disease; UC: Ulcerative colitis. Adapted from [6]. reduced dietary intake, weight loss, increased resting energy expenditure during flares, growth retardation in children, and the need for adequate bowel rest, hydration and food sensitivity screening [1]. In support of ESPEN s practice guidelines, these potential problems indicate that it is in the patient s best interest to be screened for primary nutritional problems, with referral to a registered dietitian to arrange a treatment plan and follow-up. Table 4 provides a general checklist of these nutrition-related problems that may exist in CD patients [9 16]. Patients with UC are also prone to nutritional deficiency, especially since iron-deficient anemia due to blood loss occurs in up to 80% of these patients. Dietary supplements Many of the dietary guidelines indirectly addressed nutritional deficiency by suggesting a daily vitamin/mineral supplement with physician guidance. Special consideration should be given for vitamin D and the the other fat soluble vitamins A, E and K, as well as other nutrients, such as vitamin C, vitamin B 12, folate, calcium, magnesium, iron, zinc and copper. IBD patients who are prescribed corticosteroid medications should be informed of the increased risk for osteoporosis and should receive calcium and vitamin D supplementation. Diet for IBD No diet currently exists for patients with IBD. This is problematic because when 125 pediatric IBD patients were questioned about diet, 90% of the CD patients and 71% of the UC patients revealed that they had altered their diets since diagnosis [17]. Approximately 73% of these reported that their dietary changes alleviated symptoms of abdominal pain, diarrhea and flatulence. Unfortunately, IBD patients often ask questions about diet without receiving instruction or referral to a registered dietitian. For example, when CD patients were asked if diet altered their symptoms, 78% (n = 21 out of 27), replied yes [18]. However, only 15% of these patients (n = 4 out of 27) received a dietary referral. Currently, many IBD patients continue to receive minimal dietary instruction, despite clinical practice guidelines and emerging research suggesting that dietary changes may ameliorate symptoms. In terms of existing guidelines for dietary modifications, three suggested limiting dairy if lactose intolerant, two suggested limiting excess fat, one indicated decreasing excess carbohydrates, Box 5. Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition clinical practice guidelines for inflammatory bowel disease concerning diet. Total enteral nutrition (elemental formula) and oral mesalazine are used together as the primary therapy during the onset and active stage of the disease Total parenteral nutrition with oral mesalazine is reserved for children having serious illnesses Corticosteroids should not be used until at least 1 week after starting total parenteral nutrition, and then additional amounts used if the child does not respond to total parenteral nutrition Adapted from [8]

6 Brown, Rampertab & Mullin Box 6. Crohn s & Colitis Foundation of America dietary suggestions for inflammatory bowel disease patients with strictures of the bowel. Low-fiber diet or special liquid diet may be beneficial Restrict intake of certain high-fiber foods, such as nuts, seeds, corn, popcorn and various Chinese vegetables Minimize scrappy foods, such as raw fruits, vegetables, seeds, nuts and corn hulls Eat smaller meals at more frequent intervals Reduce the amount of greasy or fried foods Limit consumption of milk or milk products if you are lactose intolerant Adapted from [106]. and five suggested avoiding high-fiber foods, especially during flares. The question of whether or not to use probiotics continues to be debated. Reducing dairy The prevalence of lactose malabsorption is significantly greater in patients with CD involving the small bowel than it is in patients with CD involving the colon or UC [19]. Symptoms of IBD and lactose intolerance often overlap, so it seems prudent to avoid lactose-containing foods if there is an intolerance. Reducing fat Some patients with IBD react to excess dietary fat and perhaps this is where the recommendation is derived. Few research studies are available to support or refute such a recommendation. The topic needs further investigation because patients with malabsorption may be at risk of not obtaining their necessary essential fatty acids. Perhaps saturated fats should be limited, with more of an emphasis on more healthy fat intakes. Reducing carbohydrates Only the WGO mentioned limited evidence suggests reducing carbohydrates [4]. The Crohn s and Colitis Foundation of America mentions the Specific Carbohydrate Diet as only being supported by testimonials, but that it might be worth a try. However, this is apart from their dietary suggestions provided for patients experiencing bowel strictures. The malabsorption and compromise of digestive enzymes on an inflamed GI tract may contribute to the small number of studies in the literature suggesting some success of the Specific Carbohydrate Diet. This popular dietary regimen described in Elaine Gottschall s book, Breaking the Vicious Cycle, is largely supported by testimonials. The diet was originally created by a renowned pediatrician to treat celiac disease and needs to be clinically tested in people with IBD. It is essentially an elimination diet in disguise that limits dairy, gluten and processed foods. It is unique in also limiting saccharides, except the easily absorbed monosaccharides, which are allowed. The purpose of removing dietary disaccharides and polysaccharides (starches) is to inhibit the growth of microorganisms in the intestines, their resulting overgrowth and therefore the possible side effects of gas, bloating and abdominal pain. Another possibility we suggest is that an inflamed intestinal wall in the duodenal region would compromise the digestive enzymes of not only lactose, but also other disaccharides, and perhaps even the enzymes for proteins and fats. Elimination diet Although not mentioned in any of the dietary guidelines, the use of an elimination diet in patients with CD has some weak support in the literature. Brown and Roy s previous review of diet and CD revealed a higher rate of food allergies in patients with IBD [1]. For example, a survey by Ballegaard et al. observed that more than half of their IBD subjects were affected by food sensitivities. They reported food intolerances occurring in 14% (n = 70) of their healthy controls, compared with 66% (n = 53) of CD subjects and 64% (n = 77) of those with UC (n = 75). The most commonly reported symptoms in this study were Box 7. The National Digestive Diseases Information Clearinghouse dietary suggestions for people with Crohn s disease (none exist for ulcerative colitis). Crohn s disease: Decreased appetite can affect nutrition needed for good health and healing Diarrhea and poor absorption of necessary nutrients may occur No special diet has been proven effective for preventing or treating CD, but it is very important that people who have CD follow a nutritious diet and avoid any foods that seem to worsen symptoms There are no consistent dietary rules to follow that will improve a person s symptoms People should only take vitamin supplements based on their doctor s advice Foods such as bulky grains, hot spices, alcohol and milk products may increase diarrhea and cramping The doctor may recommend nutritional supplements, especially for children whose growth has been slowed. Special high-calorie liquid formulas are sometimes used for this purpose A small number of patients may need to be briefly fed intravenously (through a small tube inserted into the vein of the arm) CD: Crohn s disease. Adapted from [105]. 416 Expert Rev. Gastroenterol. Hepatol. 5(3), (2011)

7 Existing dietary guidelines for Crohn s disease & ulcerative colitis Review abdominal pain, meteorism (drum-like distention of the abdomen caused by gas in the abdomen or intestines), diarrhea and flatulence. The most frequently symptomprovoking foods were vegetables (40%), fruit (28% apple, strawberries and citrus fruits), milk (27%), bread (23%), meat (25% beef and smoked meat) and others (38%) [20]. Not all IBD patients are afflicted with food allergies. The majority do react to foods so perhaps they should be tested for food allergies and food intolerances. This may also apply more for patients with CD in the duodenum, rather those afflicted in the colon or patients with UC. Allergy tests are not always reliable, so perhaps a 2-week trial elimination diet would determine if symptoms improve. This dietary method is cost-effective and such regimens have been provided to animals [21]. Reduced fiber during flares (active disease states, fistulas or strictures) Reducing high-fiber foods during symptoms appears to have generated the most support in the dietary guidelines. It may be important to communicate to IBD patients that high-fiber foods are not recommended, especially for those with CD, during flares or in the presence of active disease states, fistulas or strictures. There appears to be a tendency among the dietary guidelines to restrict foods such as raw fruits, raw vegetables, beans, bran, popcorn, seeds, nuts, corn hulls, whole grains, brown rice and wild rice. Although not mentioned, raw salads would also fall into this category. Even lower in fiber and easier to absorb are enteral feedings, which may be considered during periods of exacerbation, malabsorption or inadequate nutrient intake. These enteral feedings are preferred over parenteral with the exception of some cases of extreme malabsorption or complications, such as fistulas. Patients with CD may benefit from learning that their symptoms may be temporarily alleviated during these times if placed on an enteral diet, and that in some cases they may even avoid surgery. Enteral nutrition for CD It appears that the majority of research supporting nutrition and IBD has previously focused on enteral nutrition, sometimes inaccurately referred to as diet. Enteral nutrition (polymeric, semi-elemental and elemental) are liquid diets consisting of nutrients broken down into their smaller units. Polymeric diets contain intact nutrients that are more palatable and cheaper than Box 8. Medline Plus dietary suggestions for people with Crohn s disease and ulcerative colitis. Crohn s disease [106]: No specific diet has been demonstrated to improve or worsen the bowel inflammation in CD. However, eating a healthy amount of calories, vitamins and protein is important to avoid malnutrition and weight loss. Specific food problems may vary from person to person Certain types of foods may worsen diarrhea and gas symptoms, especially during times of active disease. Suggestions for diet during periods when symptoms are present include: Eat small amounts of food throughout the day Drink lots of water (frequent consumption of small amounts throughout the day) Avoid high-fiber foods (bran, beans, nuts, seeds and popcorn) Avoid fatty, greasy or fried foods and sauces (butter, margarine and heavy cream) If your body does not digest dairy foods well, limit dairy products Avoid or limit alcohol and caffeine consumption People who have a blockage of the intestines may need to avoid raw fruits and vegetables. Those who have difficulty digesting milk sugar (lactose) may need to avoid milk products Ask your doctor about extra vitamins and minerals you may need: Iron supplements (if you are anemic) Calcium and vitamin D supplements to help keep your bones strong Vitamin B 12 to prevent anemia Ulcerative colitis [107]: Certain types of foods may worsen diarrhea and gas symptoms, especially during times of active disease. Dietary suggestions include: Eat small amounts throughout the day Drink lots of water (frequent consumption of small amounts throughout the day) Avoid high-fiber foods (bran, beans, nuts, seeds and popcorn) Avoid fatty, greasy or fried foods and sauces (butter, margarine and heavy cream) Limit milk products if you are lactose intolerant. Dairy products are a good source of protein and calcium Avoid or limit alcohol and caffeine consumption CD: Crohn s disease. semi-elemental diets, which consist of partially hydrolyzed nutrients, or elemental diets containing completely hydrolyzed nutrients broken down into their smallest units of digestion, such as amino acids, monosaccharides, fatty acids, vitamins and minerals [22]. The nutrients are fed into the body through either the gut (enteral) or vein (parenteral). There appears to be no difference in efficacy between elemental diets (n = 188) and nonelemental diets (semi-elemental or polymeric diet; n = 146) for CD patients, according to researchers conducting a Cochrane meta-ana lysis of ten trials [23]. Enteral nutrition is considered to be a first-line therapy for adults with CD in Japan because it places patients in remission, after which they start the slide method in which a low-fat diet slowly replaces the elemental diet [24]. The half-elemental diet therapy is fed during the night through a nasogastric tube while the patient is at home and consuming a low-fat diet (20 30 g) during the day [9]. Insurance plans often dictate whether or not a particular treatment plan is pursued, and Japan s national health insurance plan covers enteral nutrition for CD [24]

8 Brown, Rampertab & Mullin Table 3. A global clinical practice guideline summarizing dietary advice for inflammatory bowel disease patients created by combining current clinical practice guidelines and informal dietary suggestions into one (not all suggestions are in agreement or based on evidence-based research). General diet IBD No special diet has been proven to be effective for preventing or treating CD symptoms or inflammation, but it is very important that people who have CD follow a nutritious diet, and avoid malnutrition, weight loss and any foods that seem to worsen symptoms. Specific food problems may vary from person to person, Decreased appetite can affect nutrition needed for good health and healing Eat smaller meals at more frequent intervals,, CD Certain types of foods may worsen diarrhea and gas symptoms, especially during times of active disease Fiber or grains IBD Decrease fiber consumption during disease activity, especially whole-grain products, bran, beans, brown rice, wild rice, nuts, corn, corn hulls, popcorn, seeds, raw fruits and certain vegetables,,, A special liquid diet may be beneficial During periods of no symptoms, slowly reintroduce high-fiber foods one at a time in small amounts Those with blocked intestines may need to avoid raw fruits and vegetables Vegetables & fruits IBD During diarrhea and abdominal pain : Dairy Recommended Well-cooked vegetables Strained vegetable or fruit juices Canned or soft fruits Peeled apple, ripe banana or melon IBD Dairy products can be maintained unless not tolerated Fat Avoid Potatoes with skins or potato skins Vegetables or fruits with seeds Corn and corn products Raw greens, beets, broccoli, Brussels sprouts, cabbage, sauerkraut, cauliflower, lima beans, mushrooms, okra, onions, parsnips, peppers and winter squash Most raw and dried fruits (see exceptions on left) Canned berries or cherries Prune juice Limit intake of milk and milk products if you do not digest dairy foods well, or are lactose intolerant,,, If tolerated, fermented foods, such as yogurt (choose live cultures) and certain low-fat cheeses, may be allowed If tolerated, nonfat, skimmed or low-fat milk products over higher fat versions IBD Avoid fatty, greasy or fried foods and sauces (butter, margarine and heavy cream), During diarrhea or abdominal pain, keep fat intake below eight teaspoons per day CD: Crohn s disease; IBD: Inflammatory bowel disease; UC: Ulcerative colitis Amy Brown. Adapted from: Clinical practice guidelines: American Dietetic Association (ADA). World Gastroenterology Organization (WGO). American Society for Parenteral and Enteral Nutrition (ASPEN). European Society for Clinical Nutrition and Metabolism (ESPEN). # Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition. Informal dietary suggestions: Crohn s & Colitis Foundation of America. National Digestive Diseases Information Clearinghouse. Medline Plus. 418 Expert Rev. Gastroenterol. Hepatol. 5(3), (2011)

9 Existing dietary guidelines for Crohn s disease & ulcerative colitis Review Table 3. A global clinical practice guideline summarizing dietary advice for inflammatory bowel disease patients created by combining current clinical practice guidelines and informal dietary suggestions into one (not all suggestions are in agreement or based on evidence-based research) (cont.). Carbohydrates IBD Limited evidence suggests reducing carbohydrates dietary fermentable oligosaccharides, disaccharides and monosaccharides, and sugar alcohols (erythritol, sorbitol, xylitol and so on, as used in sugarless products) Meats or protein foods IBD Well-cooked meats without added fat Beverages Avoid high-fat meats fried, processed (hot dogs and luncheon meats), bacon or sausage Avoid dried beans and peas Avoid nuts. Choose smooth over chunky nut butters IBD During diarrhea and abdominal pain : Probiotics Recommended Drink lots of water (frequent consumption of small amounts throughout the day), Avoid High sugar drinks Sweet juices Caffeine, Alcohol, IBD IBD may be caused or aggravated by alterations in gut flora Eat foods with added probiotics and prebiotics. Ask for advice Sugar alcohols (erythritol, sorbitol and so on) There is no evidence that probiotics are effective in either UC or CD; however, Escherichia coli Nissle 1917 is not inferior to 5-aminosalicylic acid, and VSL#3 (combination of bacterial strains ) reduced flares of pouchitis (a post-ileoanal pouch procedure for UC) Dietary supplements IBD Vitamin/mineral supplementation for all, or at least in those with malnutrition or during periods of reduced oral intake,. Ask for physician s advice, Vitamin B 12 (to prevent anemia) and vitamin D (for bones) for those that who are deficient Steroid users should receive calcium and vitamin D supplementation Iron supplements if you are anemic. Chronic iron-deficiency anemia should be treated with parenteral iron if oral iron is not tolerated CD Diarrhea and poor absorption of necessary nutrients may occur UC Iron-deficient anemia due to blood loss occurs in 80% of UC patients Liquid meals (enteral nutrition) for adults IBD A liquid diet, predigested formula or nothing by mouth may reduce obstructive symptoms CD: Crohn s disease; IBD: Inflammatory bowel disease; UC: Ulcerative colitis Amy Brown. Adapted from: Clinical practice guidelines: American Dietetic Association (ADA). World Gastroenterology Organization (WGO). American Society for Parenteral and Enteral Nutrition (ASPEN). European Society for Clinical Nutrition and Metabolism (ESPEN). # Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition. Informal dietary suggestions: Crohn s & Colitis Foundation of America. National Digestive Diseases Information Clearinghouse. Medline Plus

10 Brown, Rampertab & Mullin Table 3. A global clinical practice guideline summarizing dietary advice for inflammatory bowel disease patients created by combining current clinical practice guidelines and informal dietary suggestions into one (not all suggestions are in agreement or based on evidence-based research) (cont.). Liquid meals (enteral nutrition) for adults (cont.) CD Enteral nutrition is the sole therapy in adults during the acute phase when corticosteroid treatment is not feasible For enteral therapy, use oral supplements up to 600 kcal/day with food intake, and then tube feeding if higher intakes are necessary. Continuous tube feeding is better than bolus, owing to a lower complication rate Whole proteins are preferred as free amino acid- or peptide-based formulas are not recommended Enteral nutrition for adult CD patients requiring specialized nutrition support Liquid meals (enteral nutrition) for children IBD An exclusive enteral diet can settle inflammatory disease, especially in children CD Enteral nutrition should be given to children with growth retardation to help induce a growth spurt, Enteral nutrition should be used as an adjunct to medical therapy in those who are unable to maintain their nutrition status through oral intake Total enteral nutrition (elemental formula) and oral mesalazine is used together as the primary therapy during the onset and active stage of the disease # Enteral nutrition is indicated for the prevention and treatment of undernutrition, improving growth in children, quality-of-life improvements, acute phase therapy, perioperative nutrition and maintenance of remission in chronic active disease Vein feeding (parenteral nutrition) IBD Parenteral nutrition should be reserved for those patients with IBD in whom enteral nutrition is not tolerated Parenteral nutrition should be used in children who are unable to maintain normal growth and development on enteral nutrition or a standard diet Total parenteral nutrition with oral mesalazine is reserved for children who have serious illnesses # Corticosteroids should not be used until at least 1 week after starting total parenteral nutrition, and then additional amounts used if the child does not respond to total parenteral nutrition # CD Parenteral nutrition is usually combined with oral/enteral food unless there is continuing intra-abdominal sepsis or perforation UC Undernourished CD patients may benefit from parenteral nutrition, Despite encouraging experimental data, insufficient data exist to recommend glutamine, n-3 fatty acids or other pharmaconutrients Vitamin B 12 deficiencies are well documented, especially if the distal ileum is affected by CD or resectioned. In these patients, serum B 12 and folate should be measured annually Correct nutrient deficiencies with vitamin/mineral supplementation Fistula in CD a brief course of bowel rest and parenteral nutrition is recommended Unlike CD, both enteral and parenteral nutrition do not serve as primary therapies in UC, where nutritional deficiencies are not as common compared with CD. Enteral nutrition is only for patients with undernutrition or inadequate intake Parenteral nutrition should only be used in those with UC who are malnourished or at risk of becoming malnourished before or after surgery because they cannot tolerate food or an enteral feed Bowel rest should not be provided through the use of parenteral nutrition during acute inflammatory periods Parenteral and enteral nutrition are not recommended for maintenance of remission CD: Crohn s disease; IBD: Inflammatory bowel disease; UC: Ulcerative colitis Amy Brown. Adapted from: Clinical practice guidelines: American Dietetic Association (ADA). World Gastroenterology Organization (WGO). American Society for Parenteral and Enteral Nutrition (ASPEN). European Society for Clinical Nutrition and Metabolism (ESPEN). # Japanese Society for Pediatric Gastroenterology, Hepatology and Nutrition. Informal dietary suggestions: Crohn s & Colitis Foundation of America. National Digestive Diseases Information Clearinghouse. Medline Plus. 420 Expert Rev. Gastroenterol. Hepatol. 5(3), (2011)

11 Existing dietary guidelines for Crohn s disease & ulcerative colitis Review Table 4. Primary nutritional problems related to Crohn s disease. Potential nutritional problems Malabsorption Description Inflammation, ulceration or surgery can compromise digestion and absorption Malnutrition Affects 65 75% of CD patients [9] and may include protein-losing enteropathy, iron-deficient anemia, calcium, folic acid, iron, zinc, vitamin D, vitamin K and vitamin B12 [10]. Diarrhea may affect zinc, potassium and magnesium. Steatorrhea compromises absorption of calcium, zinc, magnesium and copper [11]. Dietary supplements are warranted, coupled with yearly routine evaluation of serum B12 and vitamin D levels Reduced dietary intake Fear of abdominal pain from consuming food, anorexia, strictures and fistulas can all contribute to malnutrition [12] Weight loss Anorexia and malnutrition contributes to weight loss in 65 75% of patients [9,13] Increased resting energy expenditure Reduced growth Osteopenia 40 50% [12] Osteoporosis 5 36% [12] Lack of bowel rest Dehydration Possible food sensitivities due to allergens and intolerances Caloric requirements can increase during flares [14] Decreased linear growth that may be expressed in adulthood, and delayed puberty occur in 40 50% of children [15] Interferes with the ability of the bowel to heal itself Due to chronic diarrhea. Lack of hydration can lead to kidney stones May trigger inflammation, contribute to symptoms and exacerbate any intestinal damage Anemia may be due to iron, vitamin B 12 and iron deficiencies. Iron deficiency is the main cause of anemia occurring in up to 80% of UC patients [16]. Osteopenia may be due to protein, calcium and vitamin D deficiencies. CD: Crohn s disease Amy Brown. In the USA, clinical practice guidelines do not appear uniform in their recommendations for enteral therapy. The ACG states, corticosteroids are more effective than enteral nutrition to induce remission in active CD patients, while the WGO indicates, An exclusive enteral diet can settle inflammatory disease, especially in children. The difference between the USA and Japan in the use of enteral therapy appears to be based on a meta-analysis of six trials (15 eligible trials were found) by Zachos et al., stating that corticosteroids are more effective than enteral nutrition [23]. In terms of pediatric patients, Dziechciarz et al. s. meta-ana lysis of seven out of 11 randomized clinical trials demonstrated similar efficacy for enteral nutrition compared with corticosteroids [25]. In Japan, Matsui et al. concluded from their review that enteral nutrition used as a primary therapy results in maintaining remissions with lower adverse reactions, fewer complications and surgeries, and lower mortality rates than patients not receiving enteral nutrition [26]. The corticosteroid over enteral nutrition conclusion appears controversial. Smith mentioned that the exclusion of two large trials due to concomitant use of other medications in the steroid arm resulted in both enteral nutrition and steroids having equal efficacy [24]. In addition, only a few meta-analyses averaging ten trials or less, exist in the literature. However, our informal literature search found approximately 36 clinical trials investigating the use of enteral nutrition in CD patients [1]. Taken alone and without comparison to corticosteroids, the majority (86% [30 out of 35]) of these studies resulted in beneficial effects of enteral nutrition to CD patients [27 56], while the remaining 14% (five out of 35) had mixed results [57 61]. Despite the inconsistent recommendations of enteral nutrition use mentioned in clinical practice guidelines, the serious side effects of corticosteroids (especially stunted growth in pediatric patients) make enteral therapy the recommended treatment in the USA for children with active CD. It is also recommended for adults suffering from malnutrition or corticosteroid complications [9]. There are also positive indications that enteral therapy may be a viable option for some CD patients, at least temporarily. Possible benefits exist in the form of improved remission and relapse rates, mucosal healing, hospitalization rates, biochemical values and nutritional status. Remission & relapse rates Researchers sometimes use 3 5 weeks of enteral therapy to place approximately 85% of their CD subjects into remission prior to being treated by an experimental drug or diet [62,63]. CD patients (aged 7 71 years) requiring hospitalization were placed on an elemental diet (Vivonex ) for 4 weeks and achieved a 92% (22 out of 24) remission rate [64]. Despite a Cochrane review stating that there was no difference between elemental diet types [23], 75% (12 out of 16) of CD patients on an elemental diet (Vivonex) went into remission compared with only 36% (5 out of 14) on a polymeric diet (Fortison ). Corticosteroid-resistant IBD cases 421

12 Brown, Rampertab & Mullin may respond to elemental therapy. Axelsson and Jarnum gave 31 subjects on high-dose prednisone therapy for 1 4 weeks an elemental diet, resulting in 44% (15 out of 31) remission [62]. Remission maintenance rates were measured among 61 patients induced into remission with drugs [50]. After 1, 2 and 4 years, remission rates were 94, 63 and 63% in the group receiving home elemental enteral hyperalimentation (HEEH), 75, 66 and 66% in the group receiving HEEH and drugs, 63, 42 and 0% in the group receiving drugs, and 50, 33 and 0% in the group receiving no maintenance therapy, respectively. These researchers concluded that elemental diet therapy was effective not only for the induction of remission, but also for the maintenance of remission in CD [50]. Mucosal healing Enteral therapy may contribute to mucosal healing, which is one of the latest therapeutic goals in the management of IBD. Several studies have demonstrated that enteral nutrition allows the GI tract to heal [27,65 68]. Elemental diets have been reported to significantly improve lactulose/l-rhamnose permeability ratios [69] and cytokine production [70], suggesting mucosal healing. An oral polymeric diet (CT3211; Nestle, Vevey, Switzerland) fed to 29 pediatric patients with CD for 8 weeks resulted in complete clinical remission in 79% of the participants [39]. The clinical response to the oral polymeric diet was associated with mucosal healing and a downregulation of mucosal pro inflammatory cytokine mrna in both the terminal ileum and colon [39]. The healing of gut inflammatory lesions occurred in 74% (14 out of 19) of CD pediatric patients receiving an oral polymeric formula compared with 33% (six out of 18) of subjects on corticosteroids [68]. Berni Canani also noted that 65% (26 out of 37) of their pediatric CD patients had improvement in mucosal inflammation compared with 40% (four out of ten) in the corticosteroid group [67]. In addition, complete mucosal healing was observed in 19% (seven out of 37) subjects in the enteral group, compared with none of those receiving corticosteroids. Enteral therapy may contribute to mucosal healing owing to decreased fecal bacterial concentrations [71] and/or decreased antigen uptake reducing the risk of an inflammatory response. Hospitalization rates Enteral nutrition was also recently reported to decrease hospitalization rates [72]. Biochemical values A total of 28 malnourished CD patients provided with oral nutrition experienced significantly increased serum proteins, creatinine height index and circulating T lymphocyte numbers, while serum orosomucoid levels dropped significantly, suggesting that disease activity was reduced [73]. Sedimentation rate and renal urea excretion decreased in certain IBD patients consuming an elemental diet [62]. In 17 pediatric patients with CD in their small intestines, linear growth (assessed from height velocity over 6 months) was significantly greater in the children receiving an elemental diet [74]. Nutritional status Enteral formulas are available to address the insufficient nutrient intake and growth failure related to IBD in pediatric patients [75]. Malnutrition is common in IBD due to decreased food intake, malabsorption, increased nutrient loss, increased energy requirements and drug nutrient interactions [76]. In pediatric patients, weight loss occurs in up to 85% of those with CD and 65% of those with UC. Approximately 15 40% of IBD pediatric patients experience growth failure, which is more common in CD than UC. It may be inaccurate to suggest that nutritional therapies (enteral nutrition) do not work based on the aforementioned data. They may work as well as pharmaceutical intervention without the side effects. The major problems of enteral nutrition are patient compliance, their limited duration of use and the 60% relapse rate that occurs after discontinuation. Other problems to consider are that elemental diets are liquid, so possible side effects of this treatment are osmolarity diarrhea, abdominal distension, colic, cholelithiasis and pneumonia (due to pulmonary aspiration) [77]. Perhaps the decision of whether or not to use enteral therapy should involve the patient with CD. Such patients should at least be made aware that enteral therapy is an option available to them, especially during manageable flares or when considering certain surgeries. Makola provides a list and cost comparison of 28 elemental, semi-elemental and polymeric formulations [78]. Expert commentary More research is needed to elucidate the evidence-based, dietary-related clinical practice guidelines for patients with IBD. Suggested research topics include, but are not limited to: Key issues Based on the above review of the current existing dietary guidelines for inflammatory bowel disease (IBD), we suggest the following regarding nutrient deficiencies, as well as the role diet may play in reducing IBD symptoms. Screen all IBD patients for nutritional deficiencies, especially children, and make the appropriate nutrition counseling referrals. Consider suggesting a vitamin/mineral supplement and or specific nutrient supplementation based on individual patient history. Overall dietary suggestions may include to eat smaller, more frequent meals, consume sufficient liquids (especially water), decrease excess saturated fat, decrease excess sugars (especially disaccharides and polysaccharides) and decrease high-fiber foods during flares. Educate IBD patients about possible food sensitivities, and suggest that a 2-week, trial elimination diet may aid in their detection. Inform Crohn s disease patients that dietary surveys often list casein and gluten as the top two food offenders. Educate Crohn s disease patients about enteral or oral elemental supplementation options that may alleviate flares, reduce hospitalization rates and increase the possibility of remission. 422 Expert Rev. Gastroenterol. Hepatol. 5(3), (2011)