Coders and designers are known for their inveterate caffeine addictions. Fearful for our cardiovascular systems, most of us (at least, those of us who've already graduated from college and come to value our longevity) eschew daily Red Bulls and Monster drinks, sticking with simpler, safer, cheaper alternatives like coffee and tea. But there's always been that nagging downside to coffee: It will dehydrate you. Won't it?
Funded by the Institute for Scientific Information on Coffee (ISIC), the study looked at 52 healthy non-smoking males aged 18–46. (Women were excluded from the study due to "possible disruptions to fluid balance by the menstrual cycle." Go figure.)
For a period of three days, the men drank four mugs of black coffee a day, (Nescafé Original) and then endured a 10-day "wash-out" period. Following the wash-out, the coffee-drinkers were asked to drink water for three days, while the non-coffee drinkers drank coffee for three days.
The resulting data suggested that moderate consumption of coffee (4mg/kg of caffeine daily) did not result in dehydration. Actually, the study indicated that "coffee, when consumed in moderation by caffeine habituated males contributes to daily fluid requirement and does not pose a detrimental effect to fluid balance." So, coffee doesn't dehydrate your system but can in fact hydrate you, adding to your suggested daily liquid intake.
Other advantages to coffee abound, including: "a reduction in the risk of developing Type 2 diabetes, basal cell carcinoma (the most common skin cancer), prostate cancer, oral cancer and breast cancer recurrence," according to the New York Times. Back in 2008, the Times theorized a similar notion to that of the new ISIC study, but there was not enough data then to support coffee's hydrating powers.
While this is the first study of its kind, it does promote the perception that drinking coffee is good for you. So whether you're drinking probiotic coffee or a tall latte from your local Starbucks made of shipping containers, don't let those naysayers tell you it's bad for your health.