This
brochure is promoted as a public service by the Digestive Health Foundation.
The leaflet cannot be completely comprehensive and is intended as a guide
only. The information given here is current at the time of printing, but may
change in the future. If you have any further questions you should raise
them with your own doctor.Introduction
The purpose of this booklet is to provide a guide for patients (both adults
and children), their families and professionals about diet and Crohn's
disease and ulcerative colitis.
The role of diet in the development of ulcerative colitis and Crohn's
disease is an area of great interest, but to date there is no evidence that
dietary factors cause Inflammatory Bowel Disease (IBD). Although a very
small number of people can have symptoms in response to certain foods, there
is no evidence that either disease is due to allergic reactions to specific
foods such as milk, wheat or gluten. Once IBD is diagnosed however,
attention to diet can help reduce symptoms and improve nutrition. This can
enhance healing and response to medications.
What is Inflammatory Bowel Disease?
IBD is a term used to describe two diseases which cause inflammation of the
small and/or large bowel. These diseases are:
ULCERATIVE COLITIS:
Inflammation of the lining of the colon (large bowel) and rectum (lower part
of the large bowel). When only the rectum is involved it is sometimes called
ulcerative proctitis.
CROHN'S DISEASE:
Inflammation of the full thickness of the bowel which may involve any part
of the gastrointestinal (digestive) tract, from mouth to the anus (back
passage). It most frequently affects the lower part of the small bowel, or
terminal ileum (ileitis), the large bowel (Crohn's colitis), or both small
and large bowel (ileo-colitis).
Is
there a special diet for IBD?
In general there is no special diet for people with IBD. There is NO
evidence that strict restrictive diets are an effective treatment for IBD.
All individuals with IBD should take a normal diet, adequate in all
nutrients. In children with IBD, adequate nutrition is particularly
important for normal growth and nutritional supplements are more commonly
required.
A small minority of individuals with IBD may require long term
modifications to their diet to reduce symptoms caused by their disease or
surgery. Some individuals with more severe forms of IBD are at risk of
malnutrition so it is important to identify and treat nutritional
deficiencies early. Individuals with active disease may find a bland, low
fibre diet more tolerable as it can minimise cramps and diarrhoea. Some
people find specific foods may worsen symptoms.
What are the components of our diet?
Food is made up of a mixture of nutrients and different foods have different
proportions of each nutrient. The most important nutrients are:
PROTEIN
Proteins are the most important component of muscle and most other body
tissues. Dietary protein is needed for growth, repair and maintenance of
body tissues, but is usually not used as a source of energy. High protein
foods include meat (beef, lamb, pork, and poultry), fish, seafood, eggs,
dairy products (milk, cheese, and yoghurt), nuts and legumes (dried beans
and lentils).
CARBOHYDRATE
Carbohydrate is the most important source of energy (kilojoules or calories)
for the body. It is found in foods such as bread, cereals, rice, pasta,
legumes, milk, yoghurt, fruit, potato and sugar containing products such as
soft drink. Carbohydrate stores are depleted within 24 hours if energy
intake is stopped.
FAT
Fat is a very concentrated form of energy which is stored by the body for
use when food intake is insufficient for any reason. High fat foods include
pastries, chips, cakes, biscuits, chocolate, fried and many takeaway foods.
Many food additives, including butter, margarine, oil, cream and salad
dressings, also have a high fat content.
The amount of carbohydrate, fat and protein in the diet make up the
total energy (kilojoules or calories) consumption. Ideally, protein
should not be a major source of energy as it is required for growth and
tissue repair. Optimal energy balance is achieved when enough food is
eaten and absorbed to meet the demands of the body's energy expenditure
(which can be increased in some people with active IBD). Adults experience
weight loss and muscle wasting if energy expenditure exceeds energy intake;
in children this leads to impaired growth.
VITAMINS
Vitamins are essential nutrients, which are necessary for normal body
function. They are present in small quantities in various foods and include
the water soluble vitamins: B group (thiamine, niacin and riboflavin),
vitamin C, vitamin B6 (pyridoxine), folate, vitamin B12 and the fat soluble
vitamins: A, D, E and K.
Vitamin B12: is required for healthy blood and nervous tissue.
Deficiency of vitamin B12 leads to anaemia. Vitamin B12 is found only in
animal foods such as beef, lamb, pork, fish, chicken, eggs and milk
products. Extensive Crohn's disease of the Ileum or its surgical removal can
interfere with vitamin B12 absorption.
Folate (folic acid): Is required for the formation of new cells,
including blood cells, and is particularly important prior to and during
pregnancy. The best sources include green leafy vegetables, wholegrain
breads and cereals, nuts, oranges, liver and yeast extracts (e.g. Vegemite).
Sulphasalazine, a drug which is commonly used to prevent relapses of
ulcerative colitis may on rare occasions interfere with its absorption.
MINERALS
Minerals are essential nutrients which are present in small quantities in
food and are necessary for normal bodily function. They include iron,
calcium, sodium, potassium, magnesium, copper and zinc. Iron deficiency is
relatively common in IBD patients. Calcium malabsorption can occur in
patients with extensive Crohn's disease of the small bowel.
Iron: is required to the formation of red blood cells. Good
sources are meat, (including liver and kidney), nuts, wholegrain bread and
cereals. Blood loss from the bowel is the commonest cause of iron deficiency
in IBD patients.
Calcium: is important for strong bones and teeth. The best sources
are milk, cheese and yoghurt.
DIETARY FIBRE (ROUGHAGE)
Fibre is the indigestible part of plant foods which assist the movement of
faeces (stool or bowel motion) through the large bowel. High fibre foods
include wholegrain breads and cereals, nuts legumes and fresh fruit and
vegetables, especially the skins and seeds.
WATER
Water is the most essential of all the nutrients. It occurs in varying
proportions in different foods. An intake of 6-8 cups of fluid per day is
recommended for adults.
What is digestion?
Digestion is the process by which protein, fat and carbohydrate are broken
down to a form which can be absorbed into the body. Vitamins, minerals and
water are absorbed without digestion.
How is food digested?
Digestion begins in the mouth where food is chewed and mixed with saliva.
Swallowed food passes through the oesophagus (gullet) into the stomach,
which acts as a reservoir. In the stomach food is mixed with acid and
digestive enzymes (chemicals which break down food). Small quantities of
food are released into the small bowel at frequent intervals. In the small
bowel digestive enzymes from the pancreas gland and bile released from the
gallbladder break down proteins, carbohydrates and fats so they can be
absorbed into the body. Bile salts, a component of bile, are essential for
fat absorption. After dietary fat is absorbed bile salts are reabsorbed from
the bowel and re-used.
Where is food absorbed?
Most nutrients are absorbed in the small bowel. The small bowel has three
parts:
| |
Duodenum |
about 20 to 30 centimetres |
| |
Jejunum |
about 80 to 120 centimetres |
| |
Ileum |
about 120 to 180 centimetres |
Products of digestion of protein, fat and carbohydrate, some water, and
most vitamins and minerals, are absorbed in the jejunum. Water, vitamin B12
and bile salts are absorbed in the ileum. If the jejunum is affected by
disease or surgery the ileum and large bowel can often compensate. However,
the jejunum is never able to take over absorption of vitamin B12 or bile
salts.
Small bowel contents are still liquid when they leave the ileum and as
these contents move through the large bowel, water is reabsorbed, resulting
in a solid bowel motion.
How
does IBD affect digestion and absorption?
Ulcerative Colitis: Ulcerative colitis only affects the
large bowel and therefore does not affect the digestion or absorption of
most nutrients. However, it can interfere with water absorption, leading to
diarrhoea. Blood and protein can also be lost from the inflamed lining of
the bowel.
Crohn's Disease: If the ileum is affected there may be decreased
absorption of Vitamin B12 and bile salts. Lack of bile salts may impair
absorption of fat. If the entire small bowel is affected (or if a large
amount of small bowel has been removed) absorption of most nutrients will be
compromised. In some patients the disease causes narrowing of the small
bowel resulting in pain and discomfort after eating. If Crohn's disease
involves the large bowel water absorption is affected, resulting in
diarrhoea.
Why do nutritional problems occur in IBD?
Poor Food Intake
Poor food intake is the commonest cause of inadequate nutrition in IBD and
may be due to poor appetite, restrictive diets or reducing food intake to
avoid symptoms such as nausea, pain or diarrhoea.
Reduced Absorption of Nutrients
Disease in, or surgical removal of, a portion of the small bowel, can
interfere with absorption.
Fever and Inflammation
Fever and inflammation increase the body's nutritional needs and interfere
with its ability to utilise food.
Loss of Protein, Blood and Fluid
Inflammation and ulceration of the bowel wall can cause significant losses
of protein, blood and water.
Medications
Side effects from medications can include nausea, abdominal pain, poor
appetite and impaired absorption of nutrients. Sulphasalazine may cause
abdominal pain or poor appetite and can sometimes interfere with absorption
of folic acid. Steroids have complex effects on nutrition and growth.
What nutritional problems can occur?
Weight Loss
Weight loss is more common in Crohn's disease than ulcerative colitis.
Unintentional weight loss of more than 10% of your usual body weight may
indicate malnutrition. Any weight loss in children is a sign of inadequate
nutrition.
Impaired Growth
Uncontrolled disease, especially when combined with a poor food intake,
leads to growth failure in children and adolescents.
Dehydration
If there is diarrhoea, vomiting or a leak from the bowel, fluid losses may
be large and cause dehydration. Extra fluid is required in warm weather when
additional water and salt is lost through perspiration.
Anaemia
The most important cause of anaemia in IBD is blood loss. A low dietary
intake of iron, folate or vitamin B12 may also contribute. Depending on the
cause of anaemia, iron tablets, folic acid supplements or vitamin B12
injections may be prescribed. A blood transfusion may sometimes by
necessary.
Reduced Protein Levels
Routine blood tests sometimes detect reduced protein levels in the blood of
patients with IBD. There are a number of causes including increased needs
because of fever, inflammation or surgery; steroid use; and, losses from
inflamed bowel - especially when dietary protein intake is poor.
Poor Fat Absorption
Fat absorption is reduced in some patients with Crohn's disease because of
extensive small bowel disease or loss of bile salts. These individuals
develop bowel actions containing fatty diarrhoea (steatorrhoea) which is
pale in colour, smells offensive and may be difficult to flush away.
Lactose Intolerance
Lactose is a natural carbohydrate found in milk which cannot be absorbed
without digestion by the enzyme "lactase", which is usually found in the
wall of the small bowel. Lactase may be destroyed by active Crohn's disease.
Lactose intolerance causes cramp, wind, diarrhoea and abdominal bloating. It
also occurs in may individuals who do not have IBD.
Dietary management of IBD
Aims:
1. Maintain good nutritional status
2. Promote adequate growth in children
3. Control symptoms
Treatment: Remember that in general there is no special diet to
treat IBD. Most individuals with IBD should eat a varied, interesting diet
which maintains weight and contains all essential nutrients. It is best to
avoid any food which seems to worsen symptoms.
Recommended minimum daily intake
Breads and Cereals
At least 4-5 serves daily. Provides carbohydrate, B group vitamins and some
minerals. Wholemeal and wholegrain varieties provide dietary fibre.
|
1 serve
|
=
|
1 slice bread |
| |
or
|
1 cup cooked rice or pasta |
| |
or
|
1 cup breakfast cereal |
Fruit and Vegetables
At least 5 serves daily. Choose from fresh, frozen or canned. Provide
carbohydrate, folate, beta-carotene (Vitamin A), Vitamin C and minerals.
They also provide dietary fibre (especially skins and seeds)
|
1 serve
|
=
|
1 medium sized piece of fruit |
| |
or
|
1 cup vegetables or salad |
| |
or
|
1 glass fruit juice |
Meat and Meat Alternatives
Eat 1-2 serves daily. Excellent source of protein, Vitamin B12, niacin,
iron and zinc. Legumes are high in dietary fibre.
|
1 serve
|
=
|
90-150g meat, fish or chicken |
| |
or
|
2 eggs |
| |
or
|
1 cup cooked legumes |
Milk and Dairy Foods
Eat 3-4 serves daily. Important for calcium, protein, Vitamins A and D and
minerals.
|
1 serve
|
=
|
250ml (1 cup) milk |
| |
or
|
35g cheese |
| |
or
|
200g tub yoghurt |
Fats and Oils
4-6 teaspoons daily is all that is needed by most people. They are an
important source of fat soluble vitamins. They are very high in energy so
may be useful if weight gain is required, however, should be used sparingly
by individuals who are overweight and by those with poor fat absorption.
Fluids
Drink at least 6 cups of fluid daily, particularly if you have diarrhoea.
High energy drinks such as soft drinks, cordial, fruit juice and milk drinks
may be useful if you are underweight.
When is a special diet required?
If modifications to diet are required it is best to consult with a dietician
to ensure a nutritionally adequate diet.
| |
1 |
Low Fibre Diet
A low fibre diet is sometimes helpful to control diarrhoea. Reduced
fibre may also be recommended to prevent pain and nausea after eating
for individuals with Crohn's disease with narrowing of the small bowel.
Avoid seeds, nuts, legumes (dried beans and lentils) and dried fruit.
Limit fruit and vegetables, especially sweet corn and don't eat skins
and seeds. Choose white bread and refined breakfast cereals instead of
wholegrain and wholemeal varieties.
|
| |
2 |
Low Fat Diet
A low fat diet may be recommended for Crohn's disease patients with
fatty diarrhoea (steatorrhoea). Low fat diets are generally not
recommended for children because fat is an important source of the
energy needed for normal growth and development.
Avoid adding fat (ie oil, lard, dripping, margarine, cereal, mayonnaise,
butter) to foods and minimise use in cooking. Limit intake of high fat
foods such as chips, chocolate, pastries, fried foods, cakes and
biscuits. Choose low fat dairy products and lean meats; it is important
not to cut these foods out of the diet as they are good sources of
protein. |
| |
3 |
Low Lactose Diet
A lactose free diet may be required if lactose
intolerance is present.
Milk and milk products (e.g. cheese, yoghurt) are the only sources of
lactose. However, they are important sources of protein and calcium.
Your dietitian will advise you how to overcome this problem.
|
Are Vitamin or Mineral Supplements Necessary?
Vitamin and mineral deficiencies can occur in IBD, particularly if the diet
is restricted. However most individuals with IBD do not require supplements.
A small number of IBD patients require additional iron, folic acid, calcium
or vitamin D, which are usually given a s tablets. Injections of vitamin B12
every 3 months may be necessary if the ileum is diseased or has been
removed. Nutritional supplements are more likely to be recommended for
children with IBD to maintain normal growth and development.
Are
Nutritional Supplements Necessary?
A small number of people with IBD are unable to maintain weight. Several
liquid supplements are available which provide additional nutrients to
supplement food intake. If you require nutritional supplement you will be
advised by your dietician.
What about Alcohol?
There is no evidence that alcohol taken in moderation causes or worsens IBD.
Alcohol may increase the effect of medications that are taken to relieve
anxiety, depression or insomnia. Metronidazole (Flagyl) can interact with
alcohol and it is usually best to avoid having alcohol while taking this
drug.
What If I Am too Sick to Eat Enough?
A small number of patients with IBD are too unwell to eat enough to maintain
weight, even if supplements are used. Liquid supplements can then be given
via a small tube that passes through the nose to the stomach (nasogastric
tube). This is called "enteral nutrition". This type of feeding is usually
only performed in hospital, although it can be continued at home if
necessary. There is some evidence that the enteral feeding may have some
effect as a treatment for Crohn's disease, particularly in children. Rarely,
patients with severe IBD need to be fed via a needle placed into a vein in
the upper chest. This is called "parenteral nutrition" and is always
commenced in hospital. It is rarely used at home.
What happens after Surgery?
If the large bowel is totally removed (colectomy) the small bowel slowly
takes over its function. Initially bowel actions are liquid but slowly
become less fluid as the small bowel absorbs more water.
Removal of part of the ileum is a common operation for Crohn's disease.
If a large amount of ileum is removed absorption of bile salts and vitamin
B12 may be impaired. If Vitamin B12 supplements are required, they must be
given by injection, usually once every three months. Failure to absorb bile
salts can cause fatty diarrhoea (steatorrhoea) or diarrhoea. Individuals
with steatorrhoea may require a low fat diet. Diarrhoea is due to irritation
of the large bowel by bile acids and can be controlled by a drug called
cholestyramine (Questran).
Children/Adolescents and Nutrition
Children with IBD need a normal diet of good wholesome food, to allow normal
growth and development. Simply getting the child or adolescent to eat
anything he/she feels like eating is the first step. At times this it not as
easy as it sounds.
Sometimes IBD impairs the child's ability to digest certain foods and
some dietary modification is needed. For example, a low lactose diet may be
necessary if milk is causing abdominal bloating, cramps, excessive gas and
diarrhoea. Any dietary restrictions need to be discussed with your child's
doctor and dietician. Some children need specialised dietary treatment,
usually for a limited time (a few weeks or months), because they cannot
tolerate normal food or are too ill to eat. This may involve liquid
nutritional supplements or, very rarely, enteral or parenteral nutrition.
Conclusion
Nutrition is an important part of the management of ulcerative colitis and
Crohn's disease. A normal healthy diet is best for most IBD patients.
However, a small number require dietary supplements or special diets. You
should never commence any dietary treatment until you have discussed it with
your doctor or dietician.
AUSTRALIAN GASTROENTEROLOGY INSTITUTE 