Why is Nutrition Important in Cystic Fibrosis?

What is Cystic Fibrosis?

CF is genetic disorder that is inherited in an autosomal recessive manner. It is caused by the presence of mutations in both copies of the gene for the cystic fibrosis transmembrane conductance regulator (CFTR) protein.

Those with a single functional copy of the gene are carriers and are otherwise mostly normal. CFTR is involved in production of sweat, digestive fluids in the GI tract and mucus in the respiratory tract. When CFTR is not functional, secretions in the lungs and GI tract, which are usually thin, becomes thick and sticky.

The condition is diagnosed by a sweat test and genetic testing. Screening of infants at birth takes place in some areas of the world.

What are some Cystic Fibrosis Symptoms?

Chronic coughing, frequent lung infection, failure to thrive in infant and children, malnutrition in adults, steatorrhea (fatty stool).

Cystic Fibrosis and Nutrition

“Pass the Butter, Please” is probably a very common phrase whispered at the dinner table of families with CF.

We all know people with CF needs a lot of calories in forms of fats and butter, they also need a lot of salt and other nutrients.

Research suggested that nutrition is linked to CF survival. The research shows that the CF population in Toronto, Canada had a significantly better survival rate compared to the CF population in Boston, MA. The only difference found between the groups was that the CF patients in Canada weighed more.

Study also shows that nutrition is linked to lung function. A study of about 3,300 CF patients over the age of 2, shows that CF patients who have normal body weight (regardless of infection status) maintain better FEV1% predicted and have less lung function decline over years compared to CF patients who are malnourished.

CF Foundation Guidelines

Data collected by the Cystic Fibrosis Foundation over the years also suggest a link between nutrition and lung function. Based on these data, the CF Foundation put out guidelines for children to achieve a BMI of 50%ile or above, and the BMI recommendation for adults are 23 for men and 22 for female.

Malnutrition may affect lung muscles that are needed for breathing. Malnutrition may also affect tissue repair mechanism in people with CF. Malnutrition also affects the immune system and increase susceptibility to infection.

How Does CF Affect Digestion?

The absence or malfunction of the Cystic fibrosis transmembrane conductance regulator (CFTR) prevents the movement of Cl- ion into and out of cells, causing buildup of thickened mucous in the airway.

This defective CFTR is also present in the GI tract affecting proper digestion and absorption of nutrients.

The organ most affected is the pancreas, resulting in exocrine pancreatic insufficiency.

The exocrine pancreas normally produced digestive enzymes, such as amylase, protease and lipase to digest carbohydrates, protein, and fats respectively.

In exocrine pancreatic insufficiency, the production of these enzymes is halted by the buildup of thickened mucus just like in the lungs.

The nutritional consequences of exocrine pancreatic insufficiency is steatorrhea (or fatty stool), fat-soluble vitamins (A, D, E, and K) deficiency and minerals (calcium and zinc) from fat malabsorption.

CF and Inflammation

Another less frequently noticed reason why nutrition is important is that nutrition can affect inflammation.

CF is an inflammatory disease. The abnormal CFTR causes thickened mucous in the lungs, which results in obstruction, then infection, and inflammation. This process goes on and on, damaging lung tissue along the way.

Patients with CF has lower levels of glutathione, which is an important immune modulator to help reduce inflammation. CF patients also have a defective fatty acid metabolism, which results in low levels of linoleic acid and DHA, which are anti-infammatory, and increased level of arachidonic acid, which is pro-inflammatory. The current diet for CF in high in saturated fats, trans fats and omega-6 fatty acids, all of which are increase inflammatory.

We know there are food that can cause inflammation and there are food that can reduce inflammation.

An anti-inflammatory diet can help reduce the inflammation and slow down the progress of CF lung degeneration.

The anti-inflammatory diet is rich in omega-3 fatty acids (DHA & EPA) and polyphenols. It replaces unhealthy pro-inflammatory fats with healthy fats, such as extra virgin olive oil, organic grass-fed butter, fish oil, etc.

Research suggested that supplementation with DHA & EPA may reverse the defective fatty acid mechanism in CFTR.

The anti-inflammatory diet is also rich in antioxidants from fresh fruits, vegetables, herbs, and spices.

Read Anti-inflammatory Diet for Cystic Fibrosis