Updated 07 November 2014

Cystic fibrosis and your diet

Cystic fibrosis is a relatively common hereditary or genetic disease, which can have a devastating effect on health.


Cystic fibrosis is a relatively common hereditary or genetic disease, which can have a devastating effect on health.

Nowadays survival of this previously lethal genetic disorder has improved greatly thanks to early detection and the use of intensive treatments, including nutrition interventions.

Symptoms of cystic fibrosis
According to a report by the Nutrition Information Centre of the University of Stellenbosch (NCIUS), cystic fibrosis is characterised by some, or all of the following symptoms:

  • Excessive mucus production by the cells that line the lungs, the intestine, the sweat glands, the pancreas (the gland which produces insulin), the liver and the reproductive tract.
  • The thick, sticky mucous produced by patients suffering from cystic fibrosis can block any one of the ducts in the above mentioned systems, for example it may clog the lungs to such an extent that the patient cannot breathe properly, while the mucus can also damage lung cells. This can lead to constant coughs, wheezing and lung infections (acute and chronic bronchitis, pneumonia) and other respiratory complications.
  • The mucous secretions can also block the ducts that transport digestive enzymes from the pancreas to the intestines, thus hampering digestion of food and absorption of nutrients. Patients, therefore, have an increased appetite, but fail to gain weight or to grow normally. They usually also produce smelly stools caused by malabsorption of fat, a condition called steatorrhoea.
  • Patients often have salty tasting sweat, while their fingers may have clubbed ends and look slightly blue. These patients are also sensitive to heat exhaustion and dehydration. In some cases cystic fibrosis leads to sterility in male patients. Diabetes and liver complications are also common.
  • Problems with digestion caused by a lack of digestive enzymes can lead to poor absorption of fat, abdominal pain, and even intestinal obstruction. Patients may also suffer from reflux and heartburn, vomiting caused by excessive coughing, loss of appetite, constipation and bloating.
  • Diseases of the digestive tract such as Crohn’s disease and coeliac disease (serious sensitivity to all products that contain gluten) are also more common in patients with cystic fibrosis.
  • Cystic fibrosis sufferers may be more susceptible to diabetes and glucose intolerance is common.
  • Constant infections of the lungs can also increase the patient’s needs for energy, but if the patient has a poor appetite and is already suffering from weight loss, trying to supply the energy needs of such patients is very challenging.

Treatment of cystic fibrosis
Medical treatment
Patients with cystic fibrosis need to be under the management of a medical team that usually includes a physician, a physiotherapist and a dietician.

Medical treatment may include all of the following:

  • Antibiotics(oral and inhaled) to treat respiratory and other infections
  • Inhalants to assist with breathing
  • Physiotherapy to help patients move mucous out of the lungs and other organs
  • Additional feeds by mouth or tube, particularly when the patient has to be hospitalised
  • Supplementation of digestive enzymes

Diet therapy
Diet therapy in cystic fibrosis is one of the most important aspects of treatment to ensure normal growth and development. If you, or any member of your family, is affected by this genetic disease, then it is important to consult a clinical dietician to assist you with the correct diet for various stages of the patient’s life, for example to meet the increased requirement for energy and protective nutrients during childhood and the teenage years, and in adulthood to boost resistance to infections and supply enough energy for the patient’s needs despite poor digestion and absorption.

Vital dietary needs
Each one of the following nutrients may be affected by cystic fibrosis:

Due to problems associated with blocked pancreas and liver ducts, patients do not have sufficient enzymes and/or bile salts in the small intestine to absorb enough energy from foods for their daily needs. Chronic undernutrition is one of the most common features of this disease and diet therapy must aim to boost energy intake.

Most patients need to ingest up to 50% more energy than normal. Thus a child of seven to 10 years who would generally only require 2 000 kcal (8 400 kJ) per day, would need to ingest 3 000 kcal (12 600 kJ) a day to provide sufficient energy for his needs. An adult woman of 25 who would usually require 2 200 kcal (9 2000 kJ) per day, would need to boost her energy intake with an additional 1 100 kcal (about 4 600 kJ) every day.

If the patient has no appetite, is underweight and experiences a host of symptoms that interfere with eating, caregivers are faced with a seemingly insurmountable problem.

However, there are ways of ensuring that cystic fibrosis patients have an adequate energy intake. One  solution is to increase the fat content of the diet. In contrast to most people who need to cut down on fat intake, cystic fibrosis sufferers should be encouraged to add cream or butter to foods such as cereals, potatoes, desserts and fruit. They should also use full-cream milk and dairy products instead of the fat-free varieties.

High-energy snacks between meals can also assist to increase the so-called ‘energy-density’ of the diet, for example full-cream yoghurt, cream cheese or ice cream, bread with butter, jam and peanut butter, milk shakes made with full cream milk, pureed fruit and honey, or cheese with wholewheat crackers.

(Written by Dr IV van Heerden, DietDoc)

(Health24, updated August 2011)


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