Library.

“Coffee consumption stunts human growth (reduces height growth).”

Available evidence does not support the idea that drinking coffee reduces human height growth. Clinical guidance from major pediatric and medical sources treats this as a debunked myth, and studies in adolescents have not shown lower height growth from caffeine intake. Caffeine can still be a problem for children and teens because it can disrupt sleep and cause other health effects, but that is different from stunting height.

“Consuming caffeine via energy drinks is worse for health than consuming an equivalent amount of caffeine via coffee.”

The evidence indicates that energy drinks generally cause more adverse acute cardiovascular effects than the same amount of caffeine from coffee. Randomized trials show larger changes in blood pressure and electrical heart measures after energy drinks, including one direct caffeine-matched coffee comparison. But the claim is broader than the evidence: most studies are short-term, use surrogate markers, and do not prove worse overall or long-term health outcomes in every circumstance.

“Daily coffee consumption, when the coffee is consumed at least 8 hours before bedtime, is bad for health.”

The evidence does not support the claim. High-quality reviews generally find moderate daily coffee consumption is associated with neutral or favorable health outcomes, not broad harm. The main bedtime-caffeine studies examined 0, 3, and 6 hours before sleep, so they do not establish that coffee consumed at least 8 hours before bed is harmful overall.

“People need to drink extra water to compensate for dehydration caused by drinking coffee.”

The evidence does not support the idea that coffee generally dehydrates people enough to require extra water. In typical amounts, coffee contributes to daily fluid intake and does not cause meaningful net dehydration in most adults. A mild diuretic effect can occur at high caffeine doses, but that does not justify a blanket rule that people must compensate with extra water after drinking coffee.

“Consuming caffeine while cortisol levels are elevated reduces the stimulant effect of caffeine compared to when cortisol levels are not elevated.”

The available evidence does not support this claim as stated. Studies show that habitual caffeine use can blunt caffeine's ability to further raise cortisol levels — but this is a different outcome from caffeine's stimulant effect on alertness, which is primarily mediated through adenosine receptor blockade. No source in the evidence pool directly measures whether pre-existing elevated cortisol reduces caffeine's wakefulness or alertness properties. The claim conflates two distinct physiological pathways, creating a materially misleading impression.

“Taking caffeine before a period of sleep deprivation can fully restore social memory function that would otherwise be impaired.”

A 2026 peer-reviewed study did show caffeine reversed social memory deficits in male mice via a specific hippocampal CA2 mechanism. However, the claim's unqualified language — "fully restore social memory function" — overgeneralizes from a single animal model and one narrow social-recognition assay. No human evidence confirms this effect. Broader research shows caffeine often only partially rescues cognition under sleep deprivation and can disrupt recovery sleep. The core finding is real but the claim's framing is misleading.

“Drinking coffee causes dehydration in humans.”

This claim is false. The scientific consensus, supported by peer-reviewed meta-analyses and major health authorities like the NHS, is clear: moderate coffee consumption does not cause dehydration in healthy adults. Coffee's mild diuretic effect is transient and far outweighed by the water content of the beverage itself. The only studies showing negative fluid balance used extreme caffeine doses in caffeine-deprived subjects—conditions irrelevant to normal coffee drinking. Regular consumers develop tolerance to caffeine's diuretic effects.