With summer finally upon us, hydration is more important than ever. If you are not taking in enough fluid to produce adequate sweat on a hot day, you may be more vulnerable to heat stroke. Dehydration can be caused by extreme heat, but it can also exacerbate other heat-related conditions such as heat cramps.
Taking in liquids is crucial, but hydration can go beyond simply drinking water. The popular belief that we all need to be drinking eight glasses a day to be truly hydrated persists, though it has been debunked again and again.
“There’s really no data behind the eight glasses of water a day thing,” says Dr Dan Negoianu, a nephrologist (someone who specialises in diagnosing and treating kidney problems and diseases) at the University of Pennsylvania. For example, “just because your urine is dark, that doesn’t prove that you’re dehydrated”.
Being hydrated simply means consuming enough fluids to the point where you are not thirsty, Dr Negoianu says, and that amount varies for everyone.
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There are plenty of things besides plain water that will keep you hydrated, experts say: These include the foods and drinks that appeal to you, the things that will keep you consistently reaching for them. Here are a few suggestions.
Look to your favourite fruits, veggies and drinks
“We think that we need to drink a lot of water all the time because we hear that all the time,” says Tamara Hew-Butler, a sports medicine scientist, who specialises in fluid balance. “You gotta drink your eight glasses – hydrate, hydrate, hydrate.” But any food or drink that has fluid content will be hydrating, she says. “Your body doesn’t care where hydration comes from, it just needs fluid.”
Fresh fruits and vegetables are ideal sources because not only do they tend to hold high water content, but they also have fibre, which provides other benefits for your diet and health. Melons, such as watermelon, honeydew or cantaloupe, are especially juicy. Strawberries, oranges, grapes, cucumbers and celery are also packed with water.
Beverages of all sorts can be hydrating. Juice, milk, tea and coffee each contain fluids that your body can use. Drinks with high sugar content might not be the best nutritional choice, but research shows that sugar-sweetened beverages are just as good as water at delivering fluids to your system. In the heat of summer, of course, frozen desserts such as ice pops and sorbets are handy vessels for liquid consumption.
“You can achieve, and exceed, your daily fluid requirements through the ingestion of beverages and high moisture foods without drinking a single glass of plain water,” Hew-Butler says.
Caffeinated drinks can be hydrating, too. Though caffeine is often deemed a diuretic, or dehydrating substance, research shows that consuming coffee or other caffeinated beverages has about the same hydrating or dehydrating effects as if you just drank water – especially if you are a regular caffeine consumer.
If you are having a significant amount of caffeine after a long period without it, you might experience a small blip of dehydration, says Kelly Hyndman, a researcher at the University of Alabama at Birmingham who studies kidney function and fluid retention. But otherwise, caffeine will not cause dehydration, she adds – at least not at the levels people typically consume it.
Don’t be afraid of savoury foods
You have probably heard that salty foods are dehydrating, but that is not strictly true, Hyndman says.
Our bodies are constantly looking to maintain a salt-to-water balance, which they do with the help of a number of hormones. One of the most prominent of these is the antidiuretic hormone, or ADH.
When we consume a lot of salty foods at once, our brains will secrete ADH, which in turn tells our kidneys to hold on to water, preventing us from peeing out excess fluid. At the same time, the brain secretes another hormone, vasopressin, which is linked to feelings of thirst. Together, all these hormones signal that you need more fluids. Consuming too many salty foods is an issue only if you are also ignoring your thirst cues, Hew-Butler says.
If you are looking for savoury foods that are hydrating, olives and pickles are acceptable choices, though it is rare that people consume those in large quantities. Soup, especially with water-based broths, can also help you get your fill of water.
But what is actually dehydrating is alcohol. “Alcohol suppresses ADH,” Hyndman says. So when you consume it, “you don’t have this hormone telling your kidney to reabsorb water” and any fluids you consume will go straight through you.
Make sure kids, elderly and others get their fill
“Most of us who say we’re dehydrated probably aren’t,” Hyndman says. While there are probably some people who are walking around a little dehydrated, she adds, the majority of folks are adequately hydrated or even a little overhydrated. If you have complained of having a small bladder, or you are just peeing more often than you would like, maybe you do not need to be consuming so much fluid – it is just flowing through you.
Those who need to be most diligent about actively hydrating are children, older adults and people with underlying medical conditions, Hyndman says.
The rest of us simply need to have a drink or eat foods full of fluids when we are thirsty, Hew-Butler says, and trust our instincts. “We don’t need to overthink it,” she says.
“I think the ‘drink when you’re thirsty rule’ is one that’s hard to argue against,” Negoianu says, barring medical conditions or ultra-harsh environments that might cause abnormal water loss. “When it comes to the amount of water you need, it’s like Goldilocks and the Three Bears.”
Just as Goldilocks had to decide for herself which porridge was just right, every person has to find the hydration level that is just right for them and their situation. — This article originally appeared in the New York Times