Does anything hydrate better than water? The surprising truth about superior fluids

October 2, 2025 •

4 min read

According to a study from Scotland's University of St. Andrews, some beverages actually hydrate the body more effectively than plain water. This surprising finding delves into the nutritional science behind whether anything can truly hydrate better than water under certain conditions.

Quick Summary

Certain beverages and foods can provide superior hydration compared to water in specific situations. Drinks containing a strategic balance of electrolytes, carbohydrates, and protein can improve the body's fluid absorption and retention, especially during illness or intense exercise.

Key Points

Nutrient Composition: Beverages containing electrolytes (like sodium and potassium), carbohydrates, and protein can slow stomach emptying and improve the body's ability to retain fluids.
Milk is a Surprise Winner: Studies have shown that both skim and whole milk can be more hydrating than plain water due to their content of lactose, protein, fat, and electrolytes.
ORS for Severe Dehydration: Oral Rehydration Solutions (ORS) are specifically formulated with glucose and electrolytes to treat dehydration caused by illness like diarrhea and vomiting, making them more effective than water in these cases.
Sports Drinks for High-Intensity Exercise: For workouts lasting over an hour or in hot conditions, sports drinks can be more effective than water because they replenish both fluids and lost electrolytes and provide energy.
High-Water Content Foods: Foods like watermelon, cucumber, and lettuce significantly contribute to daily fluid intake and provide additional nutrients, supplementing liquid hydration.
For Most Cases, Water is Fine: For daily life and moderate activities, water remains the best, calorie-free option for staying hydrated and supporting bodily functions.

The Gold Standard vs. The Power-Ups

Water is the universal standard for daily hydration, and for good reason. It is calorie-free, readily available, and necessary for nearly every bodily function, from regulating temperature to delivering nutrients to cells. For most sedentary or moderately active individuals, drinking water regularly is all that is needed to maintain fluid balance. However, the efficiency of hydration depends not just on the volume of fluid consumed, but also on its composition. Under specific circumstances, like periods of intense fluid loss, water alone might not be the most effective choice. This is where the concept of a 'Beverage Hydration Index' comes into play, measuring a drink's ability to retain fluid in the body over time. Beverages containing a blend of electrolytes, carbs, and protein can be absorbed more slowly, leading to prolonged hydration.

Milk: A Surprisingly Potent Hydrator

Research has shown that milk, particularly skim milk, can be more hydrating than water for a sustained period. The effectiveness of milk is attributed to its unique nutritional profile:

Natural sugars (lactose): Slows the rate at which the fluid is emptied from the stomach.
Protein and fat: Also contribute to slower gastric emptying, prolonging hydration.
Electrolytes (sodium and potassium): Act like a 'sponge' to hold onto water in the body and reduce the amount of urine produced.

This makes milk an excellent option for rehydration after a workout, as it not only replaces fluids but also provides nutrients that aid in muscle recovery. However, it may not be the best choice for those with lactose intolerance or for rehydrating during episodes of severe diarrhea, as lactose can worsen symptoms.

Oral Rehydration Solutions (ORS): The Medical-Grade Fix

For cases of dehydration caused by illness, such as severe diarrhea or vomiting, Oral Rehydration Solutions (ORS) are scientifically formulated to be more effective than water. ORS consists of a precise blend of water, glucose, and essential electrolytes like sodium and potassium. The key to its effectiveness is how the glucose helps the intestines absorb water and sodium more efficiently. This rapid and targeted rehydration mechanism is why ORS is endorsed by organizations like the World Health Organization for treating dehydration. For milder dehydration, clear broths with added electrolytes can also be very beneficial. You can even make a simple version at home by mixing salt, sugar, and water.

Sports Drinks: When is the 'Boost' Worth It?

Sports drinks are engineered for high-intensity or prolonged exercise lasting more than 60 minutes, especially in hot conditions. They provide a crucial combination of carbohydrates for energy and electrolytes (mainly sodium and potassium) to replenish what is lost through sweat. The electrolytes help increase fluid absorption and retention, making them more effective than plain water in these specific scenarios. However, for light exercise or everyday hydration, the high sugar content and calories in many sports drinks are unnecessary and can be counterproductive to health goals. For moderate activity, water is still the better choice, or a lower-sugar electrolyte supplement.

Hydrating Foods: Don't Forget to Eat Your Water

Approximately 20% of our daily fluid intake comes from foods. Incorporating water-rich fruits and vegetables into your diet is an easy and effective way to boost hydration. Some of the most hydrating options include:

Cucumbers (96% water)
Iceberg Lettuce (95.6% water)
Celery (95.4% water)
Tomatoes (94.5% water)
Watermelon (91.4% water)
Strawberries (90.9% water)
Cantaloupe (90.1% water)

Consuming a mix of water-rich foods and beverages ensures a comprehensive approach to maintaining optimal fluid balance throughout the day.

Comparative Hydration Index of Common Beverages


Beverage	Primary Hydration Mechanism	Key Nutrients	Best Used For	Notes
Water	Simple fluid replacement	None	Daily hydration, light exercise	The calorie-free standard.
Milk	Slowed gastric emptying, electrolytes	Lactose, protein, fat, sodium, potassium	Post-exercise recovery, prolonged hydration	Contains more calories; not ideal for illness.
Oral Rehydration Solution (ORS)	Optimized fluid and electrolyte absorption	Glucose, sodium, potassium	Treating dehydration from vomiting/diarrhea	Most effective for illness-induced dehydration.
Sports Drink	Replenishes fluids, electrolytes, and carbs	Sugar, sodium, potassium	Intense or prolonged exercise (>1 hour)	High in sugar; unnecessary for light activity.
Coconut Water	Natural electrolytes	Potassium, sodium, manganese	Replenishing after lighter workouts	Less sodium than sports drinks; may cause bloating.
Herbal Tea	Pure fluid absorption, antioxidants	None (plain), antioxidants	Everyday hydration, warm comfort	Moderate amounts of caffeinated teas also contribute.

Choosing the Right Drink for the Right Situation

The best hydration strategy depends on the specific circumstances. For day-to-day needs, nothing beats the simplicity and effectiveness of plain water. However, for an athlete pushing their limits, a sports drink can provide the necessary fuel and electrolytes to maintain performance. For someone recovering from an illness, an ORS is the most medically sound choice for rapid rehydration. And for an easy, nutritious hydration boost, incorporating milk or water-rich foods is a great option. Knowing when to reach for which fluid is the key to optimizing your body's performance and recovery.

Remember, listening to your body is important. Thirst is a sign that you are already mildly dehydrated. Paying attention to urine color—aiming for a pale yellow—is a reliable indicator of proper hydration. Always prioritize replacing the fluids and electrolytes lost, but be mindful of excess sugars and calories in sweetened beverages. A balanced approach to nutrition and hydration will support your overall health and well-being.

Conclusion

While water is a universally excellent choice for hydration, scientific evidence shows that other beverages can, under certain conditions, hydrate the body more effectively. Drinks containing electrolytes, carbohydrates, and protein—like milk, Oral Rehydration Solutions (ORS), and sports drinks—can slow fluid passage through the stomach and improve fluid retention. Ultimately, the superior hydrating beverage is contextual. For routine hydration, water is unparalleled. For post-workout recovery or illness-induced dehydration, specialized drinks offer targeted benefits. By understanding the science behind different fluids, individuals can make smarter choices to meet their specific hydration needs. You can find more detailed information on hydration from credible sources like the Mayo Clinic.

Frequently Asked Questions

Milk is more hydrating than water for longer periods because it contains protein, fat, lactose, and electrolytes like sodium and potassium. These components slow down the rate at which fluid leaves your stomach, allowing your body to retain it more effectively.

You should choose an Oral Rehydration Solution (ORS) over water when you are experiencing dehydration due to illness, such as severe vomiting or diarrhea. ORS is formulated to rapidly replace lost electrolytes and fluid, which water alone cannot do.

No, sports drinks are not better than water for all exercise. For low to moderate activity lasting less than an hour, water is sufficient. Sports drinks are most beneficial for high-intensity, prolonged exercise (over 60 minutes) or in hot weather, as they replace both fluids and lost electrolytes.

No, high-sugar drinks are not effective for hydration and can be detrimental. Due to a process called osmosis, their high sugar concentration can pull water from your body into the intestine to dilute the sugar, which can be less hydrating than plain water.

A simple way to check your hydration status is by observing your urine color. A pale yellow or clear color indicates good hydration, while a dark yellow color suggests you need to increase your fluid intake.

Yes, foods with a high water content, such as fruits and vegetables like watermelon, cucumbers, and lettuce, contribute significantly to your daily fluid intake. Approximately 20% of your total fluid intake comes from food.

Coconut water is a good option for post-workout rehydration after lighter exercise, as it contains natural electrolytes like potassium. However, it contains less sodium than sports drinks, which is a key electrolyte for endurance athletes.

Yes, in moderation, coffee and tea can contribute to your daily fluid intake. Research indicates that the mild diuretic effect of caffeine doesn't outweigh the hydrating effect of the water content, unless consumed in very large quantities.