Marathon runners can avoid becoming ill after a match if they ingest 326 mg gallic acid analogues daily. This must consist of 47 mg catechin, 8 mg epicatechin, 33 mg procyanidin B-3, 5 mg other proanthocyanidins, 15 mg vanillic acid, 42 mg syringa acid, 15 mg p-cumar acid, 52 mg ferulic acid, 4 mg sinapinic acid, 9 mg other hydroxycinnamic acids, 39 mg isoxanthohumol en 55 mg other flavonols. Too complicated? You can also just drink a litre of non-alcoholic beer each day.
This was the conclusion reached by sports scientists at the Technicsche Universitaet Muenchen in a study in which they had 63 marathon runners drink 1 to 1.5 litres of Erdinger Alkoholfrei every day for a week. The study was paid for by the brewer of the beer, Werner Brombach GmbH.
There are indications that phenols protect endurance athletes against illness. In some trials, quercetin does that, for example [Med Sci Sports Exerc. 2007 Sep;39(9):1561-9.] Because beer is a source of phenols – 1 litre contains 350 to 800 mg phenols – the researchers wondered if a supplement of non-alcoholic beer would help the immune system of endurance athletes when they were active.
The supplement began 3 weeks before a marathon and continued for 2 weeks after the marathon had ended. A control group of 58 marathon runners drank a product with the same nutritional value as the beer but without phenols.
And indeed. Es hat geklappt! The subjects who drank a litre of non-alcoholic beer each day were less bothered by a tickling cough, a runny nose or other symptoms of upper respiratory tract illness. Both before and after the marathon, the researchers also found fewer immune cells in the blood of the runners who had drunk non-alcoholic beer.
Eccentric exercise reduces the creation of toll-like receptors [TLR's] 2 and 4 in immune cells. [Eur J Appl Physiol. 2010 May;109(2):251-7.] With these toll-like receptors, the immune cells of the immune system can recognise pathogens. You can read more about this here.
The researchers suspect that phenols curb the breakdown of TLRS during physical exertion, a theory they propose to test in further studies.
If the researchers are right, food products or supplements based on red grapes, berries or cherries could have the same effect since they contain phenols that are somewhat similar to the phenols in beer.
Med Sci Sports Exerc. 2012 Jan;44(1):18-26.