Not what you thought: The best drink for staying hydrated in summer

Beat the heat with milk! The Israeli summer challenges us, but a study finds water isn't the most efficient drink for hydration.

  (photo credit: INGIMAGE)
(photo credit: INGIMAGE)

The Israeli summer is a challenging time for all of us, as evident from Prime Minister Benjamin Netanyahu's recent hospitalization due to dehydration. Many have stressed the importance of drinking plenty of water during this season.

However, one study conducted in 2019 at the University of St. Andrews in Scotland challenges this notion, suggesting that even if he had consumed enough water, it might not have been the most effective solution.

Surprisingly, the research found that water is not the most effective drink for keeping the body hydrated and protected from dehydration. It does rehydrate the body quickly, but other drinks with higher sugar, fat, or protein content perform even better at maintaining hydration over time.

Dehydrated? Drink milk

Interestingly, milk emerged as a more effective hydrating option than plain water. Milk contains sugar lactose, a little protein, and fat, which slow down the emptying of liquids from the stomach. This keeps you hydrated for longer.  Additionally, milk contains sodium, acting like a sponge to retain water in the body and reduce urine production.

Oral rehydration solutions used to treat diarrhea were also found to be effective due to their sugar, sodium, and potassium content, which promote water retention.

Milk (credit: MARTIN VOREL)
Milk (credit: MARTIN VOREL)

Melissa Majumdar, spokeswoman for the Academy of Nutrition and Dietetics who was not involved in this study, told CNN: “This study tells us much of what we already knew: Electrolytes — like sodium and potassium — contribute to better hydration, while calories in beverages result in slower gastric emptying and therefore slower release of urination.” 

However, the researchers caution against drinks with high sugar concentrations, such as fruit juices and soft drinks, as they may not hydrate the body effectively. These drinks stay in the stomach longer and empty more slowly than plain water, the high sugar concentration in the small intestine gets diluted through a process called osmosis, drawing water from the body, increasing the risk of dehydration.

The researchers emphasize that fruit juices and carbonated drinks are not only less effective at hydrating but also contain unnecessary sugars and calories, lacking the satiety of solid food. Thus, when choosing between soft drinks and water for hydration, water is always the better option.

Water plays a vital role in the body, supporting organs like the kidneys and liver in eliminating toxins and keeping the skin supple. It also lubricates joints, helps prevent infections, and delivers nutrients to cells. Moreover, water is the most cost-effective drink.

But this isn't important for most people. It is important for athletes and people who work long hours without breaks.

And this is especially true in Israel, where, in the blazing summer, proper hydration is key to thriving.