The experiment answers a useful question: does theanine have a strong, acute anti-stress effect on the experimenter?
Effect size is the key element of this question. If the substance was alprazolam (Xanax) instead of theanine, we would almost certainly see a strong effect here. The same would be true for heroin, ethanol, or cocaine.
It's not trying to test whether there might be a strong effect for most people or whether there are any side effects. Other experiments have been done with theanine seeking to answer those questions; the answers appear to be no and no.
Effect size is the key element of this question. If the substance was alprazolam (Xanax) instead of theanine, we would almost certainly see a strong effect here. The same would be true for heroin, ethanol, or cocaine.
It's not trying to test whether there might be a strong effect for most people or whether there are any side effects. Other experiments have been done with theanine seeking to answer those questions; the answers appear to be no and no.