Final answer:
The liver metabolizes alcohol primarily through alcohol dehydrogenase, turning ethanol into acetaldehyde and later into less toxic substances. Metabolism rates vary based on individual factors, and the only way to reduce BAC effectively is by giving the liver time. Caffeine, contrary to popular belief, does not speed up alcohol metabolism.
Step-by-step explanation:
When alcoholic beverages are consumed, the ethanol is rapidly absorbed into the bloodstream. The liver is the primary site for alcohol metabolism, handling 85% to 98% of the body's ethanol. This process occurs mainly through the action of the enzyme alcohol dehydrogenase, which converts ethanol to acetaldehyde. Subsequent reactions lead to acetaldehyde being further metabolized to less harmful substances that can be eliminated from the body.
The rate at which alcohol is eliminated from the bloodstream is relatively constant per individual and is mostly dependent on the amount of metabolic enzymes present in the liver, rather than the absolute amount of alcohol consumed. Women tend to metabolize alcohol more slowly than men. An average 70 kg person requires roughly 2.5 hours to oxidize 15 mL of ethanol. Caffeine and showers do not accelerate this metabolism; only time can effectively reduce blood alcohol concentration (BAC).
Additionally, the microsomal ethanol oxidizing system (MEOS) becomes more involved during heavy drinking, as it can handle the excess ethanol ingested. Genetic factors, body size, and the amount of alcohol dehydrogenase in the liver greatly affect individual rates of alcohol metabolism which can vary by 25-30%. For legal and safety reasons, understanding BAC in relation to driving under the influence (DUI) regulations is important.