Final answer:
The myth that drinking coffee will sober you up is false because caffeine in coffee does not accelerate the metabolism of alcohol in the liver. Only time allows for alcohol to be metabolized, and drinking coffee, despite its alerting effects, does not affect this process.
Step-by-step explanation:
The myth that drinking coffee will sober you up is untrue because coffee does not speed up the metabolism of alcohol in the body. While caffeine is a psychoactive drug that can make you more alert and improve concentration by stimulating the central nervous system, it has no effect on the liver's ability to metabolize alcohol. The process of becoming sober after alcohol consumption is only affected by the time it takes your liver to process the alcohol out of your system.
Alcohol metabolism is a biological process that cannot be hastened by caffeine or other stimulants. It takes approximately one hour for the liver to metabolize one standard drink. Therefore, if you are legally intoxicated with a blood alcohol concentration (BAC) of 0.08, it will take at least five hours to reach sobriety, regardless of how much coffee you consume.
Furthermore, the consumption of coffee itself may be connected with certain lifestyle choices, and while moderate coffee drinking has been found to potentially have some health benefits, it does not alter the fact that only time will reduce blood alcohol levels to safe limits.