Saliva in cystic fibrosis

Question

Hello,

For quite some time I am interested to learn why the saliva in CF isn’t more viscous than in healthy persons? Is its composition, amount and viscosity normal compared to the saliva of healthy persons or are there differences?
According to Wikipedia the saliva contains the digestive enzyme alpha-Amylase ptyalin which has hardly time to be effective until it is inactivated in the stomach by gastric acid. If there is ptyalin in the saliva – despite CF – does it make sense to chew the food for a long time?

Many thanks,
S. K. (2x dF508, 48 years)

Answer

Dear Mr K.,

In fact, the composition of the saliva and thus the viscosity in CF individuals is different (increased level of sodium, calcium, phosphate, urea, uric acid, fats and prostaglandin E2). However, the viscosity and the amount – like in healthy persons – mainly depend on fluid intake. By drinking enough fluids the body will produce sufficient amounts of saliva. The literature does not report an increased incidence of ptyaloliths (salivary stones) in CF. Rather dental calculus is said to occur more frequently. According to the current status of existing studies there isn’t any difference to healthy persons in terms of sense of taste.

Referring to your question about ptyalin:
Generally speaking food should be chewed properly (“well begun is half done”), however recommending an overly extensive chewing of food would go too far. Please try it yourself: Take a piece of white bread and chew it until you notice a sweet taste which results from the hydrolysis of the starch in the bread, yielding i.e. glucose. This can take several minutes for each mouthful. Please note that satiation is completed 10 – 30 minutes after having started the meal. In the context of a high calorie diet long chewing would be rather counterproductive. More effective digestive enzymes come from the pancreas. In case of exocrine pancreatic insufficiency pancreas-enzyme preparations are available and fully sufficient.

I hope to have answered your question in a satisfactory way.

Best regards,
Suzanne van Dullemen

09.07.2013