Nutrition in cystic fibrosis

We are pleased to have an overview on the nutrition needed for children with cystic fibrosis from Elizabeth (Betsy) Britt, a RD who is a member of the Cystic Fibrosis Care Team at Children's Healthcare of Atlanta.  Dr. Stan

Cystic fibrosis (CF) is an inherited disease. Both parents must give their child a gene that interferes with the amount of salt in many of the fluids the body produces. As a result, children with CF taste salty when you kiss them and thick mucus builds up in their lungs, digestive tract, and other areas of the body. The buildup in the lungs causes coughing and wheezing making it difficult to breathe. The mucus also blocks the ducts in the pancreas, preventing the enzymes that normally digest fat, sugars and protein from working effectively—causing bulky, foul bowel movements. Together these two main features use enormous amounts of energy and waste the calories being eaten.    

Fortunately, treatments are now available that helps those with CF live longer and have productive lives. As a result, more focus has been placed on better nutrition, because it improves lung function and is essential in increasing the growth and quality of life for children with CF. 

Healthy Nutrition

In those with CF, a healthy body weight is associated with good lung function, according to the Cystic Fibrosis Foundation. As a result, it is recommended that children with CF over the age of 2 years have a weight-for-length (or when they're older, a BMI) that is at least at the 50^th percentile for their size and age.  

It can be difficult to meet growth goals due to increased calorie and protein expenditure in this population. A high calorie, high protein diet without fat restriction is usually recommended—1.5 – 2 times what an otherwise healthy child would require. Many children with CF utilize nutrition supplements like Pediasure, Ensure, and Scandishake to meet these recommendations. Appetite stimulants and tube feedings can also be utilized in children who have difficulty with weight gain. 

Children with CF also lose extra salt in their sweat. So eating a high salt diet is recommended for all patients with CF. Older children and adults are encouraged to add extra salt to their foods. For babies, parents should add 1/8 teaspoon salt to 32 ounces of formula, since babies also need more salt . 

Vitamins

Children with CF are at risk for nutrient deficiencies, particularly of fat soluble vitamins A, D, E, and K. This is because thick mucus blocks the digestive enzymes from doing their job to break down fats so they can be absorbed. As a result, children with CF should take an additional CF specific multivitamin daily. 

Special CF multivitamins have enough A, D, E and K to meet what those with CF need. Some that are easily absorbed (because they are more water soluble and don't depend on fat absorption as much) include: AquADEK, Vitamax, and Libertas. 

Bottom line

Good nutrition is a necessary part of CF care. Recommendations include:

• A high-calorie, high-protein diet 
• Maintaining a weight-for-length or BMI that is greater than or equal to the 50th% for age  
• Extra salt intake 
• PERT for those who have pancreatic insufficiency
• Vitamins A, D, E, and K 
• Careful monitoring  

Resources

Leonard, A., & Schindler, T. (July 2014). Cystic Fibrosis Nutrition 101: Getting Started. 6th edition. 

Cystic Fibrosis Foundation – Patient Registry Annual Data Report 2013. (2014).