The study was done by Dr Margaret Rayman, Fiona Angus and Heidi Goenaga Infante from the School of Biomedical and Molecular Sciences with the help of 52 paid healthy volunteers.
Each volunteer attended Leatherhead Food International daily to consume either soup A (containing 200 micrograms of selenium) or soup B (placebo soup). Blood samples were taken after 7 and within 1-3 days of completing the trial.
The levels of Selenium in the participants blood was pushed up to just above 100 micrograms per litre. This is a level of selenium which is above the RDA but is high enough to have a positive effect on our health.
In addition, the taste of the mushrooms was entirely unaffected.