The immune system is largely based on the healthy functioning of the intestine and its microbiome. The intestinal barrier with its selective permeability plays an important role in this. This allows nutrients to be absorbed and pathogenic bacteria to be fended off at the same time [1]. The intestinal barrier is influenced by both physical activity and nutrient intake. For example, the body comes under stress during extreme exertion such as marathons or ultra runs, which increases intestinal permeability. Bacterial toxins such as lipopolysaccharides of the bacterial membrane (LPS) pass through the intestinal wall and enter the bloodstream, where they cause inflammation. The same effect has been observed with a diet high in fat and fructose.
At the same time, sugary drinks are considered to promote regeneration after heavy physical exertion, so the consumption of sports drinks containing carbohydrates is actually recommended. According to an intervention study conducted by the German Sport University Cologne, Leibnitz University Hanover and the University of Vienna, fruit juices and fruit juice spritzers are a better alternative, especially naturally cloudy apple juice, which is rich in polyphenols, which are secondary plant substances. The study investigated the extent to which naturally cloudy apple juice contributes to regeneration and has an effect on intestinal permeability. In the first part of the study, young, healthy test subjects received either naturally cloudy apple juice or a polyphenol-free placebo drink in their everyday lives. In the second part of the study, the effect of the drinks was tested after extreme physical exertion (ultramarathon). The concentration of bacterial toxins (LPS) in the serum was measured in each case. The diet was standardized during the study period [2].
The concentration of LPS increased after both moderate (everyday) and extreme (ultramarathon) exercise. It was found that the concentration of LPS decreased more quickly after drinking the naturally cloudy apple juice compared to the placebo drink. The reason for this is thought to be polyphenols, which occur naturally in naturally cloudy apple juice. The intake of polyphenols therefore appears to counteract a chronic stress situation of the intestinal barrier. The study concludes that polyphenol-rich fruit juices or spritzers are best suited as a drink for regeneration after physical exertion and also in everyday life. Against this background, sweetened drinks or soft drinks cannot be recommended.
Biodynamically and organically produced fruit juices differ significantly from conventional fruit juices in the way the fruit is cultivated and the additives permitted. The orchards are cultivated sustainably and without the use of synthetic chemical fertilizers. Only a few pesticides are permitted, and they are strictly limited. Some associations, such as Demeter, for example, only allow direct juice for fruit juice. This means that no juice may be reconstituted from concentrate and no added sugar may be used. The use of clarifying and filtering agents is also strictly regulated.
The study shows that naturally cloudy fruit juices positively support the intestines and the entire organism. It is an example of how minimally processed, natural products are healthy, and their effect can be proven right down to the intestines.
Bibliography
[1] Forschungskreis der Ernährungsindustrie e.V. (2024): "Untersuchungen zu protektiven Effekten von Apfelsaft auf die Darmbarriere" Forschungskreis der Ernährungsindustrie e.V. (FEI) www.fei-bonn.de/gefoerderte-projekte/projektdatenbank/21925-n.projekt retrieved on 21.06.2024
[2] Saltner R, Bergheim I, Esatbeyoglu T, Köpsel M, Kostov T, Valder S, Diel P (2024): "Untersuchungen zu protektiven Effekten von Apfelsaft auf die Darmbarriere: Effekte in Ruhe und nach moderater und extremer körperlicher Belastung (Ultra-Marathon)" Proceedings of the German Nutrition Society, Vol 30, 9
