Iced tea is a refreshing thirst quencher with several health benefits to boot. But whether or not it can replace water for hydration depends on several factors.
Brewed iced tea has health benefits that make it a good substitute for water for some of your hydration needs. But don't overdo it — watch out for caffeine, oxalic acid, sodium and added sweeteners or artificial flavors.
Is Iced Tea Hydrating?
Iced tea can be a refreshing way to rehydrate on a hot summer day — as long as you choose brewed iced tea without any added sugar or other high-calorie additives.
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Unsweetened iced tea has zero calories and a small amount of minerals, such as sodium and calcium, depending on the water used to brew the tea. You can even dress it up with a sprig of mint and a spritz of lemon for an enticing alternative to water.
"Iced tea can be seen as a source of hydration as the amount of caffeine is not excessive and tea is made with water," says Lisa Andrews, MEd, RD, owner of Sound Bites Nutrition. In addition to providing hydration, iced tea also has some health perks.
Black, green and white tea (all from the Camellia Sinensis plant) are high in polyphenols, which are antioxidants that protect the body from oxidative stress, according to a June 2012 article in Current pharmaceutical design. These plant compounds have been studied for their protective effects against inflammation, cancer and heart disease.
Does Sweet Tea Dehydrate You?
While unsweetened tea is hydrating, sweet tea could have the opposite effect.
"When you drink or eat something sugary, sugar travels from your stomach to your bloodstream, which raises your blood sugar," says Andrews. "Water will move from cellular tissue to the bloodstream to help reduce blood sugar, which can lead to dehydration." That's why you might feel thirsty after eating or drinking something sweet.
Does the Caffeine in Tea Dehydrate You?
Drinking a glass of fresh-brewed iced tea can replace some of the water in your diet. But, unless you're drinking decaf, you're also getting a small amount of caffeine.
Caffeine per 8 oz.
Caffeine is often blamed for dehydration as it causes you to pee more, but it hasn't actually been proven to cause dehydration, Andrews says.
A study of 50 habitual coffee drinkers found that total body water (which is a sign of hydration) stayed consistent whether the participants had coffee or replaced their coffee with an equal amount of water, per January 2014 research in PLOS One.
Bottled Tea vs. Brewed Tea
Buying bottled or canned iced tea may not have the same benefits as the iced tea you brew from tea bags.
Bottled teas provide the same amount of water that brewed tea does, but they can also contain hidden additives like sugars, artificial sweeteners, flavorings or dyes and extra sodium.
Bottled sweet tea can have more than 20 grams of added sugar per cup — that's almost as much as the same amount of soda. Many bottled teas also contain artificial flavors and colors. If you want your iced tea on the go, check the label and try to avoid options with added sugars.
Your best bet is to brew tea at home and drink it without any sweeteners. Steep a tea bag in a cup of hot water for 5 minutes to get the most antioxidants — you'll get more than 600 milligrams of polyphenols, per Consumer Reports.
Oxalic Acid in Tea
In one case, a man went to a health care center with weakness, fatigue and body aches. Turns out it was because he was drinking about a gallon of iced tea a day, according to the University of Utah Health. Drinking so much tea caused his kidneys to fail.
Black tea is rich in oxalic acid, which occurs naturally in many foods. Too much oxalic acid can build up in your kidneys, leading to stones that prevent your kidneys from removing waste from your blood, per a September 2020 article in Nutrients.
Drinking iced tea in moderation is safe, but if you're prone to kidney stones, you may want to discuss a low-oxalate diet with your doctor.
So Should You Drink Iced Tea Instead of Water?
People assigned female at birth need around 11.5 cups of fluid per day while people assigned male at birth need 15.5 cups, according to the Mayo Clinic. While unsweetened iced tea can help you meet those goals, you'll also want to drink plain water along with it.
Tea contains beneficial antioxidants, but it also has oxalic acid, and an excess amount can contribute to kidney stones.
The bottom line: Unsweetened iced tea is a great way to stay hydrated and can help you meet your daily hydration needs when you're bored of water, but don't make it your primary source of fluids throughout the day.
A sensible way to gauge your own fluid needs is to drink when you feel thirsty, per the Mayo Clinic. Water, milk, herbal teas (which typically don't contain caffeine) and iced tea all count towards your daily fluid intake.
- University of Utah Health: "Not Sweet: Too Much Iced Tea Causes Kidney Failure"
- Mayo Clinic: "Caffeine Content for Coffee, Tea, Soda and More"
- Mayo Clinic: "Nutrition and Healthy Eating Expert Answers"
- Mayo Clinic: "Water: How Much Should You Drink Every Day"
- Biomedicine and Pharmacotherapy: "Pharmacological Values and Therapeutic Properties of Black Tea (Camellia sinensis): A Comprehensive Overview"
- Consumer Reports: "The Health Benefits of Tea"
- Consumer Reports: "Is Iced Tea Good for You?"
- USDA: "Unsweetened Iced Tea"
- Current Pharmaceutical Design: "Tea and Health: Studies in Humans"
- USDA: "black tea"
- USDA: "Green Tea"
- USDA: "Coffee"
- PLoS One: "No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population"
- USDA: "Sweet Tea"
- USDA: "Coca Cola"
- Nutrients: "Dietary Oxalate Intake and Kidney Outcomes"