Gastrointestinal distress is known to impair performance and regeneration in sports. In addition to exercise, this may be due to dietary factors as food intolerances. Lactose intolerance (LI) is one of the most common intolerances. Up to 20% of the population of North Eastern Europe suffer from a genetic loss of the digestive enzyme lactase, which causes undigested lactose being metabolized by intestinal bacteria. These fermentation processes lead to digestive disorders e.g. abdominal pain. A reliable diagnosis is made by DNA-Seq, which is complex and expensive. Therefore, aim of the current study is to 1. asses the prevalence of LI in German elite athletes and 2. compare the genetic testing with a questionnaire about symptoms as a potential simplified diagnostic tool. For the BISp-project (AZ: 070108/19-20) 122 hockey players from the national squad and football players from the 2. Bundesliga (male: 76; female: 46; age: 19?±?4 years; height: 178?±?9 cm; weight: 71?±?10 kg) completed a questionnaire for symptoms related to LI, as well as the tolerability of various foods (also included but not mentioned: celiac disease, histamine intolerance, fructose malabsorption). Furthermore, a venous blood sample was taken to determine LCT-Genotype (GT) C-13910T. 27% (n=33) of all athletes showed T/T-GT that indicates no genetical LI. C/T-GT was confirmed in 44% (n=54) referring to a decreased lactase activity but no genetical LI. In total 29% (n=35) showed C/C-GT and therefore own the genetic disposition of LI. 40% (n=14/35) athletes with T/T-GT indicated post-meal complaints compared with 48% (n=26/54) with C/T-GT and 49% (n=16/33) with C/C-GT. Furthermore, 26% (n=9/35) with T/T-GT declared that they do not tolerate dairy products or not sure whether they tolerate, compared with 43% (n=23/54) with C/T-GT and 39% (n=13/33) with C/C-GT. Blood analysis showed similar prevalence for LCT-GT distribution in athletes compared with general population, although a few more athletes showed a genetic disposition for LI. Nevertheless, complaints are equally distributed in all GTs, that could also be caused by other intolerances, because of unspecific symptoms. Furthermore, athletes` declarations on the tolerance of dairy products are not related to GT that may be due to different lactase activity independently from genetic disposition.
© Copyright 2020 International Journal of Sport Nutrition and Exercise Metabolism. Human Kinetics. Alle Rechte vorbehalten.