Fifty male coffee drinkers drank either four cups of coffee or four cups of water daily for three consecutive days. After taking 10 days to wash out their systems, they switched and drank the other beverage four times a day for three days. Researchers tested their blood, urine, and total body water after both trials. The results? The men were equally as hydrated when they drank the coffee as when they drank the water. As it turns out, when you drink coffee often enough, the body adapts to the regular caffeine intake and “becomes tolerant” to the potential diuretic effects that coffee may have, says Sophie Killer, lead researcher and doctoral candidate at the University of Birmingham. “Your body becomes more able to regulate the fluid intake and is less susceptible to any increases in urine output that somebody who’s caffeine-naïve might experience,” Killer says. Drinking coffee regularly thus contributes to the overall fluid intake that the body needs on a daily basis to keep hydrated, Killer explains. In essence, coffee hydrates a java junkie just as much as water does. More from Prevention: How Coffee Cuts Your Diabetes Risk
