Bourbon carries 37 times the congeners of vodka, and hangovers notice
Nobody fully understands why a night of drinking produces the next morning's misery. Symptoms peak as blood alcohol falls back to almost zero, and suspects range from a toxic breakdown product to hidden methanol. No folk cure has convincing evidence behind it; only drinking less, or not at all, reliably prevents one.
The body first turns ethanol into acetaldehyde, a compound estimated at 10 to 30 times more toxic than alcohol, which can stay elevated for hours. Genetics shapes how much builds up. Many East Asians carry an enzyme variant that makes acetaldehyde unusually fast, and about half of East Asians clear it slowly, producing the facial flushing known as the alcohol flush reaction. Because that reaction is so unpleasant, people with the variant are less likely to become alcoholics. The next product, acetate, may add to headaches: rats given sodium acetate showed pain behaviour, which disappeared when they received caffeine, a blocker of the brain chemical adenosine.
Congeners, the extra compounds formed during fermentation and ageing, seem to make matters worse. Darker drinks carry more of them, and all four studies comparing drink types found darker liquors produced worse hangovers. One ranking ran from diluted pure ethanol and beer at the mild end to red wine and brandy at the harsh end. A 2006 study found it took about 14 standard beers to trigger a hangover but only seven or eight servings of wine or spirits. Methanol, one potent congener, is a leading candidate for delayed symptoms: ethanol blocks its breakdown, so it lingers until the alcohol is gone and only then becomes formaldehyde and formic acid. That may explain why a morning drink seems to postpone the pain.
Dehydration gets much of the popular blame, yet studies suggest electrolyte shifts play only a small part, and water is unlikely to cut a hangover's severity much. Other contributors include immune signalling changes, lower blood sugar, disrupted sleep, stomach acid stimulated by alcohol, and lost B and C vitamins and minerals. Drowsiness and muddled thinking are the dominant features, and about 12 per cent of drinkers report the anxious state nicknamed hangxiety.
The costs reach beyond the individual: missed work, weaker job and exam performance, and impaired driving or machine operation the following day.
Source: Hangover
