Restrictive Diets Are to Be Avoided

The Malabsorption of Commonly Occurring Mono- and Disaccharides: Levels of Investigation and Differential Diagnoses by Prof. Dr. med. Martin Raithel, Dr. med. Michael Weidenhiller, Dr. med. Alexander Hagel, Urban Hetterich, Prof. Dr. med. Markus F. Neurath, Prof. Dr. med. Peter C. Konturek in volume 46/2013

The prevalence of 30–40% reported in the article cannot be concluded from the references (1). This rate corresponds roughly to the rate of self-reported food intolerances or the results of laboratory based chemical diagnostic evaluation (for example, H₂ breath test, lactase polymorphism).

Since diagnostic gold standards and non-selected patient cohorts are lacking, robust data on the prevalence rates of carbohydrate intolerance are not available.

In view of the physiological variance, unnecessary dietary restrictions on the basis of pathologically rated tolerance levels should be avoided (2). Even in 0% lactase activity, the ingestion of >12 g lactose (≈240 mL milk) may remain non-symptomatic; only a third of individuals who are symptomatic in the lactose stress test avoid milk in their daily diets.

Phylogenetically related restrictions of lactose and fructose intake are of teleological importance (for example, protection from obesity, metabolic syndrome) (3).

The non-negligible proportion of psychosomatic (functional) factors cannot be identified without using double-blinded, placebo controlled food stress testing. During such tests, the full clinical symptoms of carbohydrate malabsorption (meteorism, stomach pain, diarrhea) should be present, and the sustainability of the therapeutic effect must be monitored. (Physiological) “adult hypolactasia” can be excluded by molecular genetic testing.

In contrast to immunological (protein related) food intolerances (allergies, celiac disease), the extent of fructose and lactose restriction can be titrated at the individual level. When they are given, a sufficient intake of calcium (vitamin D, vitamins, minerals, and dietary fiber) should be ensured (4).

The aim remains to allow patients a wide range of natural foods (to prepare for themselves), rather than limiting them to restrictive diets and the associated consumption of industrially produced ready meals.

DOI: 10.3238/arztebl.2014.0148b

Janna Riechmann
Dr. med. Jan de Laffolie
Prof. Dr. med. Klaus-Peter Zimmer
Klinik für Kinder- und Jugendmedizin,
Kindergastroenterologie
Universitätsklinikum Gießen

Conflict of interest statement
The authors declare that no conflict of interest exists.

References

1. Raithel M, Weidenhiller M, Hagel AFK, Hetterich U, Neurath MFK, Konturek PC: The malabsorption of commonly occurring mono- and disaccharides—levels of investigation and differential diagnosis. Dtsch Aerztebl Int 2013; 110(46): 775–82

2. Gibson PR, Newnham E, Barrett JS, Shepherd SJ, Muir JG: Review article: fructose malabsorption and the bigger picture. Alimentary pharmacology & therapeutics 2007; 25: 349–63

3. Disse SC, Buelow A, Boedeker RH, et al.: Reduced prevalence of obesity in children with primary fructose malabsorption: a multicentre, retrospective cohort study. Pediatric obesity 2013; 8: 255–8

4. Zimmer KP: Laktose- und Fruktosemalabsorption. Monatsschr Kinderheilkd 2007; 155: 565–76