My friend, aged 29, gets drunk with just a few rounds of beer. The most he can tolerate is four bottles of small-size (300ml) bottle. Last time he passed out just after five bottles. It makes it difficult for us to hang out with him, yet we often have to. Can alcohol tolerance be manipulated?
As described by you, your friend is able to tolerate only small amounts of alcohol. Tolerance to alcohol, that is, where one can drink without being intoxicated or passing out is variable among individuals. Those with a higher body mass are able to tolerate more alcohol as compared to thinner persons. The tolerance also varies as per the amount of alcohol dehydrogenase (group of enzymes that metabolise alcohol in the body) present in the body. This is also variable among populations across the world. High level of tolerance to alcohol in Europe is said to be probably due to centuries of drinking. In liver diseases, the tolerance to alcohol is reduced, because it is unable to detoxify the alcohol consumed. The amount and type of alcohol consumed, nutritional status, are other factors that influence tolerance to alcohol.
If one increases the amount of alcohol consumed gradually over few days, he can tolerate it well. But this also increases the risk of addiction where one is compelled to drink it regularly. Regular alcohol consumption leads to many chronic health related problems including liver diseases. As liver gets diseased even small amounts can cause one to become inebriated. Thus, a vicious circle is set up. In the best interest of your friend it is advised that do not encourage him to improve tolerance to alcohol, but motivate him to reduce and stop alcohol consumption if possible.