Hot or cold—no matter your choice, coffee is a beloved beverage that people enjoy. Most people drink coffee for the instant boost of energy and several other reasons, including improved concentration and mood. Thanks to the caffeine content in coffee, it stimulates the central nervous system to improve alertness and reduce fatigue. Coffee is also rich in antioxidants and offers several other health benefits, such as lowering the risk of heart disease and diabetes. However, it is often linked to dehydration. Let us find out if coffee causes dehydration or if it is merely a myth.

Coffee is a diuretic

For the unversed, diuretics promote the release of excess water, salts, poisons, and accumulated metabolic products, such as urea from the body. Although people enjoy coffee for its caffeine content, little do they know that it has a diuretic effect on the kidneys. This is particularly true when consumed in large quantities, according to a study published in the Urology Annals Journal. Coffee acts as a natural diuretic and increases the production and excretion of urine. This effect is primarily due to caffeine, which stimulates the kidneys to release more sodium and water into the urine.

Excessive coffee consumption may cause dehydration! Image courtesy: Adobe Stock

As a result, you might find yourself urinating more often after drinking coffee. While diuretics are used medically to manage conditions like high blood pressure and fluid retention by helping to balance bodily fluids, improper use or excessive consumption can impact hydration levels.

Can coffee dehydrate you?

"Coffee itself is not likely to dehydrate you. So, the concern mainly arises from consuming too much caffeine. It has a diuretic effect, which increases urine production and can lead to water loss. This is why some people worry that caffeinated drinks like coffee might cause dehydration," explains dietitian and nutritionist Deepika Jayaswal.

While this diuretic effect can lead to temporary fluid loss, moderate consumption of coffee does not typically result in significant dehydration. In fact, coffee is made of more than 98 percent water and if you drink it regularly, your body will build up a tolerance to caffeine over time and you will be less likely to experience the diuretic effects. However, remember one thing that drinking excessive amounts of coffee or other caffeinated beverages can increase the risk of dehydration.

What does science say?

According to a 2014 review published in the Journal of Science and Medicine in Sport, caffeine does not cause dehydration in healthy adults, even during exercise. The review analysed studies where participants consumed a typical amount of caffeine, about 300 mg from coffee or other sources, and found no effect on hydration levels.

Additionally, a 2014 study in the Public Library of Science One observed 50 regular coffee drinkers over three days. Participants were divided into two groups—one drinking only water, the other drinking both water and coffee. The study found no significant difference in total body water between the two groups, indicating that moderate coffee consumption does not lead to dehydration.

How much coffee is safe to consume?

For many of us, a cup of coffee is all we need to kickstart the day. While coffee offers several benefits, such as helping us stay alert and focused, it is important to consider its caffeine content.

Avoid drinking too much coffee a day! Image courtesy: Adobe Stock

The US Food and Drug Administration (FDA) recommends that adults limit their caffeine intake to no more than 400 milligrams per day. This amount is roughly equal to four cups of brewed coffee, 10 cans of cola, or two energy drinks. Consuming more than this recommended limit can increase the risk of dehydration, especially if your daily fluid intake primarily comes from caffeinated beverages or if you are not drinking enough water.

How to tell if you are dehydrated?

Dehydration occurs when the body loses more fluids than it takes in, leading to an insufficient amount of water to carry out essential functions. This imbalance can result from inadequate fluid intake and excessive fluid loss through sweating, vomiting, and diarrhoea. Dehydration can be life-threatening, especially for babies, children, and older adults. Symptoms of dehydration include:

• Excessive thirst
• Dry mouth
• Reduced urine output
• Dark-coloured urine
• Fatigue
• Dizziness
• Confusion
• Headache

Severe dehydration can cause rapid heartbeat, low blood pressure, sunken eyes, and make you faint. To prevent dehydration, it is crucial to drink fluids regularly, especially in hot weather or if you are ill. Read more on dehydration signs here.

Headache is common if you are dehydrated. Image courtesy: Freepik

7 tips to deal with dehydration

• Aim for at least 8 glasses of water daily (around 2 liters) to keep yourself well hydrated.
• Eat fruits and vegetables with high water content, like cucumbers, oranges, and watermelon, to boost fluid intake naturally.
• Keep a check on the urine colour. It should be light yellow. Dark urine can be a sign of dehydration.
• Carry a water bottle with you to sip on throughout the day.
• Use apps or alarms to remind yourself to drink water from time to time.
• Limit caffeine and alcohol consumption, as they can increase fluid loss.
• Drink water before, during, and after physical activity to replace lost fluids.

To enjoy the benefits of coffee, keep yourself hydrated!

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