The physiology of alcohol is well understood, which makes the persistence of the myths notable.
Absorption
Through the stomach and small intestine into the bloodstream.
Which food slows rather than prevents.
Metabolism
Processed by the liver at a roughly fixed rate.
Which nothing meaningfully accelerates.
What does not work
Coffee, cold showers and food after drinking.
Which affect alertness rather than blood alcohol.
Individual variation
Body composition, sex and genetics affecting response.
Why the folk remedies do not work
The liver processes alcohol at a roughly constant rate that is not affected by coffee, food eaten afterwards, exercise or cold water.
Which means those things change how alert someone feels without changing how impaired they are.
That gap between feeling alert and being impaired is precisely what makes the remedies dangerous rather than merely ineffective.
Food before drinking
Slowing absorption and lowering peak levels.
Which does genuinely help, unlike food afterwards.
Hydration
Alcohol acting as a diuretic.
Which contributes to hangover symptoms.
Sleep
Alcohol disrupting sleep architecture.
Which is why sleep after drinking is less restorative.
A general note
This is general physiology and not medical advice.
What actually reduces the effects
Drinking less, drinking more slowly, eating beforehand, and alternating with water.
Which are the only interventions with any real basis, and none of them makes drinking more safe rather than less unpleasant.
The rate of metabolism is essentially fixed, so time is the only thing that lowers blood alcohol, and it takes considerably longer than most people assume.
Hangovers
Multiple mechanisms including dehydration, inflammation and sleep disruption.
Which is why no single remedy works.
Interactions with medication
Serious in several common cases.
Which pharmacists will advise on.
Long-term effects
Liver, cardiovascular and cancer risks documented.
A general note
Health services provide free confidential advice and support.
Why the production side is worth knowing
Drinks are among the most heavily marketed products there are, and a great deal of what is said about them is designed to justify a price rather than to explain a process. Heritage, craft, tradition and small batch are all words doing commercial work.
The processes underneath are genuinely interesting and largely documented. Fermentation, distillation, ageing and blending are technical disciplines with real constraints, and understanding them makes it considerably easier to tell the difference between a product that reflects a genuine method and one that reflects a design brief.
It also makes the money easier to place. Knowing that duty is a large share of a cheap bottle, that ageing costs a producer volume every year, and that appellation rules constrain method rather than guarantee quality explains most of what price actually reflects.
A note on drinking
Nothing here is intended to encourage drinking, and the health evidence on alcohol has moved in one direction over recent years. Guidance in several countries has been revised downwards, and no health body now describes alcohol as beneficial.
Anyone concerned about their own drinking, or someone else’s, can get free and confidential help from national health services and from support organisations in almost every country. That help is available regardless of how much someone drinks and does not require anyone to have reached a crisis first.
A general note
Production rules, labelling requirements, duty structures, licensing and health guidance all differ substantially between countries and change. National regulators, tax authorities and health services publish the applicable rules and are the authoritative source.
A closing thought on the subject
Drinks are one of the oldest manufactured products there are, and almost every technique in current use was arrived at empirically long before anyone could explain why it worked. The science came afterwards and mostly confirmed what producers had already established by trial and error over centuries.
That history is worth holding onto when a product is marketed as an innovation. Most of what is genuinely new in this industry is in measurement, consistency and scale rather than in method, and there is no shame in that: reliably making the same good thing every time is a harder achievement than it sounds.
Where to read further
Trade bodies, production institutes and regulators publish technical material on all of this, most of it written for producers rather than for consumers and consequently much clearer about what actually happens. Brewing and distilling institutes, oenology departments and national food standards agencies are the obvious starting points, and almost all of their introductory material is freely accessible.
A final note on the industry
Drinks production is one of the few sectors where genuine craft, industrial scale and heavy marketing sit side by side under the same category names, and telling them apart from a label alone is frequently impossible.
Knowing the processes is the most reliable way to read past that, because the constraints of fermentation, distillation and ageing are real and expensive and cannot be shortcut by branding. Everything else on a label is a claim; the process is a fact.