Nutrition in IBD

Written by: 
Dr Sarah Brewer

Could making changes to my diet have a positive effect on my symptoms? This is one of the most common questions asked by people with IBDAn abbreviation for inflammatory bowel disease, a group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis..

Although there is no one approach that will help everyone, a number of dietary changes are worth trying to see if they can help you as an individual.

If a test food does cause side effects, you continue to avoid it and wait until all the symptoms have improved before testing another food

As inflammationThe body’s response to injury. of the bowel affects how well you digest and absorb foods, however, it is important to follow a diet that, as well as being gut-friendly, is as nutritious as possible, to prevent you becoming deficient in any vitamins and minerals.

Different dietary approaches may help different conditions or symptoms.

On this page:

Elimination diets

Elimination diets are based on the observation that certain foods may trigger a flare-upTerm to describe an episode when the symptoms of a condition worsen. of bowel symptoms, while other foods may help to maintain symptom-free periods.

Although there is no one food that consistently causes symptoms in every single person, researchers have identified some common culprits, and the aim is to eliminate these and check what happens.

The LOFFLEX diet for Crohn's disease

The so-called LOFFLEX (low-fibre, fatOne of the three main food constituents (with carbohydrate and protein), and the main form in which energy is stored in the body.-limited exclusion) diet is designed for people with Crohn's disease.

It suggests that you avoid eating foods which bowel specialists have identified as being the most likely to worsen symptoms in their patients. The list of foods you are advised to exclude, and those that you are allowed to eat, is as follows

LOFFLEX diet recommendations
 
Foods that are NOT allowed
Foods that ARE allowed
Pork Other lean meat and poultry
Fish in batter/oil/tomato All other fish and shellfish
Milk (cow's, goat's, sheep's) and dairy products (eg eggs, yoghurt) Soya products
Wheat, rye, barley, millet, buckwheat, corn, oats Rice, rice cakes, rice milk and rice cereals
Yeast Tapioca, sago
Pulses, onion, tomatoes, sweetcorn All other vegetables, including potatoes (two portions per day, no skins)
Citrus fruit, apples, bananas, dried fruits All other fruits (two portions a day, no skins)
Vegetable, corn and nut oils Sugar, honey, jam
Nuts and seeds Fruit and herbal teas
Tea, coffee, alcohol (e.g. white wine), squashes, cola Water

Your diet isn't restricted for long, however. Once you have followed the LOFFLEX approach for two weeks, you start reintroducing new foods as long as you are symptom-free. It is not recommended that you follow the fully restricted part of this diet for more than four weeks.

New 'test' foods are introduced, one at a time, over the course of 4 days, to see if you can tolerate them. The exceptions are wheat products, which you must test for 7 days - the reason is that the appearance of symptoms is often delayed after reintroducing this cereal into your diet.

The first foods to be introduced are generally, in order, pork, oats, tea and rye, because these are least likely to cause unpleasant symptoms, with the last foods to be reintroduced including citrus fruits, wheat, yoghurt, nuts and sweetcorn, as these are the foods that seem most likely to trigger symptoms.

If a test food does cause side effects, you continue to avoid it and wait until all the symptoms have improved before testing another food. If no reactions occur, you can start testing a new food after 4 days.

Tip: Keeping a food and symptom diary will help identify the foods that you need to avoid long-term

In one study, over half of people who followed the LOFFLEX diet were still free from symptoms after 2 years.

This diet can be nutritionally balanced if you eat a variety of permitted foods, and you start introducing new 'test' foods within 2-4 weeks. If you find you need to avoid lots of foods because they worsen your symptoms, it is important to seek dietary advice, and to consider taking a vitamin and mineral supplement if an analysis of your diet suggests this is necessary.

Tip: When avoiding dairy products, you can get your missing calciumAn element that forms the structure of bones and teeth and is essential to many of the body's functions. from green vegetables such as kale and broccoli, and calciumAn element that forms the structure of bones and teeth and is essential to many of the body's functions.-enriched soya milk

Dietary approaches for ulcerative colitis

Researchers have found a way to link the food and drinks consumed by people who have ulcerative colitis with the appearance of their bowel lining, by looking inside the bowel with a special telescope (sigmoidoscopy). This has allowed them to pinpoint the food and drinks most likely to cause symptoms.

They found that foods containing sulphites (often added as a preservative) or caffeine may be important triggers, as follows.

Foods linked with active ulcerative colitis
Foods not associated with ulcerative colitis
Burgers, sausages and other preserved meats (except organic products containing no sulphites) Pork, bacon
Beer (except German beer, which is sulphite-free), lager Beef, beef products
Red and white wine Fish
Sulphite-containing soft drinks, e.g. fruit squash made from concentrates Raw apples, pears, bananas, citrus fruits, melon
Coffee (except decaffeinated brands) Milk, yoghurt, cheese
Prawns, scampi, shellfish (only if they contain sulphites) Soup (home-made, not tinned or dried)
Dried fruit and vegetables (if they contain sulphites) Breakfast cereals
Processed fruit pies and fruit cakes Lettuce, tomatoes, potatoes, peas, beans
Foods containing sulphites  
Foods containing the sulphur-rich seaweed carrageenan (Irish Moss, E407)  

Other researchers also found that people with ulcerative colitis are most likely to relapse if they have a high intake of red and processed meat, protein, alcohol and sulphur-rich foods.

Sulphites (and caffeine) interfere with the action of vitamin B1 (thiamin), which is an important nutrient for friendly, digestive bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. (see more information on Probiotics).

Some sulphur compounds (such as hydrogen sulphide) have also been shown to damage the bowel lining and produce changes similar to those seen in ulcerative colitis. Although the bowel is usually able to remove any harmful elements from these sulphur substances (detoxification), this ability may be reduced in people with ulcerative colitis, some of whom have higher than normal levels of sulphur compounds in their bowel.

While this is by no means proven, you may benefit from reducing your intake of sulphur-rich foods to see if this helps improve your symptoms.

In addition, there may be a link between ulcerative colitis and coeliac diseaseSensitivity of the lining of the intestine to the protein gliadin, resulting in poor intestinal absorption with stunted growth. - an autoimmuneAny condition caused by the body’s immune response against its own tissues. condition caused by a reaction to gliadin, a small protein found in wheat gluten. Similar small proteins are found in rye and barley.

Although this is not proven, you may benefit from trying a gluten-free diet if other dietary approaches have not helped you. A gluten-free diet is best followed under the supervision of a dietician or other healthcare professional.

Tip: The number of probiotic bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. in the bowel can be improved by eating a foodstuff called resistantA microbe, such as a type of bacteria, that is able to resist the effects of antibiotics or other drugs. fibre

Probiotics and prebiotic fibre

Probiotics are friendly, digestive bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. that produce beneficial substances such as butyrate. Butyrate acts as a 'food' for the bowel lining cells (called colonocytes). Abnormal breakdown of butyrate has been suggested as a possible cause of ulcerative colitis.

Butyrate levels are reduced by the action of sulphur compounds in the bowel (one reason why sulphur-rich foods may worsen ulcerative colitis symptoms). By helping to maintain butyrate levels, probiotic bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. may have a beneficial role to play in inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis..

The number of probiotic bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. in the bowel can be improved by eating a foodstuff called resistantA microbe, such as a type of bacteria, that is able to resist the effects of antibiotics or other drugs. fibre, such as that found in oatbran. This type of fibre (sometimes referred to as prebiotics) is not digested by human beings, but can be used by probiotic bacteriaA group of organisms too small to be seen with the naked eye, which are usually made up of just a single cell. to fuel their growth in the colonThe large intestine..

In a small study, 22 people with 'quiet' ulcerative colitis A form of inflammatory bowel disease causing inflammation and ulceration of the colon.(that is, who currently had no symptoms) ate 60g/2oz oatbran per day (mainly added to bread). Within one month, their bowel concentrations of butyrate had increased by over a third and, over the 3 months of the trial, none of them experienced any repeat of their colitis symptoms.

As oatbran may offer other health benefits, such as helping to lower cholesterolA substance present in many tissues and an important constituent of cell membranes although high concentrations of a certain type of cholesterol in the blood are unhealthy. levels, it is worth increasing your intake of this fibre source if you have an inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis..

Another source of resistantA microbe, such as a type of bacteria, that is able to resist the effects of antibiotics or other drugs. fibre is psyllium seed (Plantago ovatum, also known as ispaghula). A study involving 102 people with ulcerative colitis found that taking 10g of these seeds per day increased butyrate levels, and may be as effective in keeping ulcerative colitis symptoms at bay as a standard drug treatment (mesalazine, also known as mesalamine).

Unfortunately, not enough research is currently available to show whether or not taking probiotic supplements themselves is beneficial for people with inflammatory bowel diseases.

See the practical help page on Probiotics.

Fish oils

Fish oils are a rich source of omega-3 essential fatty acids that help to reduce inflammationThe body’s response to injury. in the body. Eating oily fish has been shown to help people with other inflammatory conditions, such as rheumatoid arthritisInflammation of one or more joints of the body., and might also have a beneficial effect on inflammatory bowel diseases.

Unfortunately, the evidence does not currently support this theory. Although one small study showed a positive effect in helping people with ulcerative colitis, more research is needed. Similarly, research looking at whether fish oils might help people with Crohn's disease has not found significant benefit.

Tip: Fish-oil capsules that are 'enteric-coated' may be more beneficial than ordinary gelatin-coated capsules, according to limited research

As fish oils have other beneficial effects in the body on heart, circulatory and joint health, it is worth increasing your intake of oily fish (including salmon, herring, mackerel and sardines) to see if this helps your overall health.

Vitamins and minerals

People with inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis. are at risk of a number of vitamin and mineral deficiencies. This is partly because they may follow a restricted diet, and partly because bowel inflammationThe body’s response to injury. can reduce absorption of some nutrients.

As a result, even people who have been newly diagnosed with IBDAn abbreviation for inflammatory bowel disease, a group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis. may have low levels of riboflavin (B2), folate, beta-caroteneA type of vitamin. It gives yellow and orange fruit and vegetables their colour., vitamin B12, calciumAn element that forms the structure of bones and teeth and is essential to many of the body's functions., phosphorus, magnesium, selenium, zinc and vitamin D. People with long-standing Crohn's disease are also likely to have low levels of ironAn element present in haemoglobin in the red cells. and of fatOne of the three main food constituents (with carbohydrate and protein), and the main form in which energy is stored in the body.-soluble vitamins, including vitamin K.

As well as regulating calciumAn element that forms the structure of bones and teeth and is essential to many of the body's functions. absorption, vitamin D may also reduce immune responses linked with IBDAn abbreviation for inflammatory bowel disease, a group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis., which means it is important to make sure you don't become deficient in this important nutrient.

Lack of the B vitamin folate (folic acid) has also been linked with an increased risk of developing colorectal cancerAbnormal, uncontrolled cell division resulting in a malignant tumour that may invade surrounding tissues or spread to distant parts of the body. in people with ulcerative colitis.

It is therefore advisable to obtain individual nutritional advice from a dietician or doctor to help reduce your risk of future health problems such as ironAn element present in haemoglobin in the red cells. -deficiency anaemiaA reduced level of haemoglobin, which carries oxygen in the blood. Anaemia causes tiredness, breathlessness and abnormally pale skin. and osteoporosis A condition resulting in brittle bones due to loss of bony tissue.(brittle bones). It may be wise to take a multivitamin and mineral supplement.

Glucosamine

Inflammatory bowel disease has been linked with reduced activity of an enzymeA protein that speeds up chemical reactions in the body without being used up itself., glucosamine synthetase, which is involved in bowel wall repair.

A pilot study in which children with chronicA disease of long duration generally involving slow changes. inflammatory bowel diseaseA group of inflammatory conditions of the intestine. The two major forms are Crohn’s disease and ulcerative colitis. took N-acetyl glucosamine supplements showed promise as a safe, inexpensive treatment, with 8 out of 12 children clearly having benefitted in terms of their symptoms and in the appearance of their bowel wall.

This is by no means proven, however, as large trials are needed to confirm this finding in both children and adults.

Tip: If you do decide to take a glucosamine supplement, it is important to look for one marked 'N-acetyl glucosamine', not 'glucosamine sulphate' (the more common form available)