You can't put a price on health, and the same goes for your morning cup of coffee. Many people regularly drink coffee in the morning before they head off to work or school. The benefits of drinking coffee are many and varied—including staying alert, having more energy, and concentrating. However, most people can't seem to agree on coffee and hydration.
Does a cup of coffee hydrate or dehydrate you? Let’s talk about the reality of coffee and hydration.
Does coffee dehydrate you?
According to the NCBI, coffee is among the most consumed dietary ingredients globally. 62% of Americans drink coffee daily, with some consumers having more than three cups a day. If you spend more time drinking coffee than water, it's natural to ask yourself if it harms your hydration.
Some studies show coffee's diuretic effect on the kidneys, especially in high doses. Diuretics are substances that cause you to make more urine than usual, and caffeine increases blood flow to your kidneys, forcing them to release more water through urine.
As a result, compounds like caffeine with diuretic properties can affect your hydration.
Types of Coffee and Caffeine Content
Different types of coffee have varying caffeine content. Since caffeine impacts your hydration, different coffees may have contrasting results.
Made from freeze-or spray-dried coffee beans, instant coffee is easy to brew. The simple instruction on making this type of coffee is to mix 1 to 2 teaspoons of the beverage with hot water. Instant coffee has a significantly lower caffeine content than regular coffee with 30 to 80 mg per 8-ounce (240ml) cup.
Brewed coffee is the most popular type of coffee in the United States. It's made by pouring boiling water over ground coffee beans and completed by a French press, filter, or percolator. An 8-ounce cup of brewed coffee has 70 to 140 mg of caffeine or 100mg on average.
Espresso is brewed by pouring a small amount of water through finely-ground coffee beans. Whether it's smaller in volume than brewed coffee, it's very high in caffeine. One shot of espresso (1.75 ounces or around 40ml) contains approximately 63 mg of caffeine.
Decaffeinated coffee, or decaf, is made from coffee beans, with at least 97% of their caffeine removed. However, the name can be deceiving. Decaf coffee is not entirely caffeine-free. One 8-ounce cup of decaf can have up to 7 mg of caffeine or 3 mg on average.
Coffee is Unlikely to Dehydrate You
Although the caffeine in most coffees will have a diuretic effect, it's not likely to dehydrate you, at least not in small amounts. Studies show that you need to consume more than 500 mg a day for caffeine to experience substantial diuretic effects; this is the equivalent of five brewed coffees.
Researchers observed that drinking higher caffeine coffee had short-term diuretic effects, while regular and low caffeine coffees had a hydrating impact. More studies showed that moderate coffee consumption is as hydrating as drinking water.
A study of 50 heavy coffee drinkers revealed that drinking 25 ounces of coffee every day for three days was equally as hydrating as drinking the same amount of water. In addition, an analysis of 16 studies revealed that drinking three cups of brewed coffee in a single sitting increased the production of urine by only 3.7 ounces, compared to other non-caffeinated drinks.
Therefore, even though coffee makes you urinate more, it doesn't dehydrate you.
To Sum Up
Coffee contains caffeine, a substance with diuretic effects. However, you need to drink up to five cups of coffee at once before the caffeine can significantly affect your hydration. And even then, you'll still not be dehydrated because the fluid you consume is more than you'll lose.
Drinking a cup of coffee does not negatively affect your hydration and can help you reach your daily fluid needs. So, drink in moderation, and you can go about your day with your usual water intake.