The next time you’re thirsty, you may want to reconsider reaching for a glass of water.
According to a new study out of St. Andrews University in Scotland, there might be better options for quickly hydrating your body — namely, beverages with more sugar, fat or protein.
For example, the study found milk to be more hydrating than water. Milk contains sugar lactose, protein and fat, and researchers believe these help to slow the emptying of fluid from the stomach, which allows hydration to happen over a longer period of time.
Out of the 13 “common beverages” tested by researchers, still water was ranked the 10th most hydrating beverage over a four-hour period.
The most hydrating drink was skim milk, followed by “oral rehydration solutions” (like Pedialyte) and full-fat milk. Orange juice and cola were next on the list.
Sparkling water was ranked 11th, directly behind still water.
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While these findings are interesting, registered dietitian Stephanie Hnatiuk doesn’t recommend you stop drinking water altogether. In fact, it’s still the “recommended beverage of choice for keeping us hydrated throughout the day,” she said.
“We get other nutrients (like fats, sugars, proteins and electrolytes) from the foods we eat so there’s generally no need to choose beverages specifically for their hydration abilities if we’re eating regular meals.”
However, a dehydrated state — which can come on after a long endurance exercise or working outside on a very hot day, for example — occurs when water and electrolytes are lost in sweat.
“In this case, it is true that choosing a beverage with some electrolyte-replacement qualities (such as the ones used in the study) can be a good idea,” Hnatiuk said.
However, Hnatiuk warns that some of these results should be taken with a grain of salt. Specifically, she doesn’t recommend replacing water with drinks high in sugar.
“We should absolutely still be limiting the added sugars we get from beverages, and while milk is a great, nutritious option for providing us with protein, vitamins and minerals, we don’t need to drink more milk throughout the day than water,” she said.
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Ultimately, Hnatiuk said this information applies more to athletes than it does to the general population.
“These findings would be more suited to an athletic population who are participating in regular, prolonged bouts of exercise (typically longer than 90 minutes),” she said.
Symptoms of dehydration
Staying hydrated is important because it “helps the heart pump more blood through the blood vessels to the muscles and it helps the muscles work efficiently,” said Ingrid Fan, registered dietitian at Loblaws Markham in Ontario.
Dehydration is caused by “not drinking enough fluid or by losing more fluid than you consume,” Fan said. This can happen through sweating, tears, vomit, urination or upset gastrointestinal issues like diarrhea.
“The severity of dehydration can depend on several factors, such as climate, level of physical activity and diet,” said Fan.
Symptoms of dehydration can include increased thirst, dry mouth, fatigue, decreased urine output, urine that is more yellow than normal, headache, dry skin and dizziness, according to Fan.
Fan agrees with Hnatiuk’s assessment of the study, adding: “That’s not to say we should all switch from drinking water to drinking milk, but depending on one’s food intake, physical activity level as well as variety of foods in the diet, one can consider milk to be a source for hydration in addition to water intake.”
“The study confirmed what we already know: beverages that contain electrolytes like sodium and potassium can contribute to better hydration,” Fan said. This is because the sodium in those beverages “act like sponges” that hold onto the water in our bodies, resulting in less urine in the body.
Water: sparkling or still?
Fan still recommends drinking water on a daily basis.
“Our body is 60 to 70 per cent water. We need water to help us digest food, carry nutrients, remove waste, cushion organs and maintain fluid and electrolyte balance,” she said.
However, there’s been some debate about whether carbonated water packs the same punch when it comes to hydration.
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“There is no evidence that carbonated or sparkling water is bad for us,” Stephanie Dang, registered dietitian and co-founder of Vancouver Dietitians, previously told Global News.
“But you should always read the label to watch out for added sugar and salt. A common mistake people make is thinking that tonic water and soda water are the same.”
In fact, tonic water has 43 grams of sugar and 58 milligrams of sodium per 16-ounce bottle. Considering the average daily intake of sugar should be 37.5 grams for men and 25 grams for women, you could exceed your daily sugar allowance with just one bottle of tonic water.
With regards to hydration, “the only difference is the added carbonation,” Dang said.
— With files from Global News