>A healthy liver can deal with quite a lot of alcohol and acetaldehyde with not much issue. But in evolutionary terms, this is not true at all. Humans today ar

>A healthy liver can deal with quite a lot of alcohol and acetaldehyde with not much issue. But in evolutionary terms, this is not true at all. Humans today are consuming way more alcohol than the metabolic pathway can handle. Alcoholic spirits are a recent invention, they were first created ~4000 years ago, which is far to little time for a metabolic pathway to adapt. If you read the wikipedia article, it says humans typically consume 3g of ethanol per day, as it is naturally produced in (fermented) food. Fruit, for example, is typically 0.6% ethanol by weight, higher if let ferment. The ability to metabolize ethanol is an important evolutionary adaption, as it allowed our ancestors to eat rotten/fermented food, especially advantageous when there was no other food to eat. However, when modern humans consume 2-3 drinks of alcohol, they are loading their body with 30-50 grams of ethanol, far more than the metabolic pathway can handle. This is a whole week's worth of ethanol, which is now being consumed in one hour. This leads to toxic amounts of ethanol and acetaldehyde accumulating in the bloodstream. Humans were never meant to consume this much alcohol. If you are wondering why humans started consuming alcoholic spirits in the first place, I am quite favorable towards the frugivory by-product hypothesis.