Have you heard of lettuce water? If not, check your feed. It's the newest trend on TikTok, and it promises to help you fall asleep faster. We had to get to the bottom of this. Here's what to know about lettuce water, which has 27 million views and counting.

First of all, when did TikTok become everyone's favorite source for so-called health trends? Recently, chlorophyll was garnering millions of views, so tried adding the green droplets to our water, hoping to see benefits of clear skin and better gut health. Then we checked out the newer craze of drinking "proffee" (protein powder in their coffee) in the morning. After that, we were somewhat horrified to watch people try "Dry scooping," or throwing back a scoop of pre-workout powder like a shot of tequila. (One woman reported that it triggered a heart attack.)

Now, we're checking out the newest health trend that's reached more than 27 million views,  "lettuce water," which is supposed to help people get to sleep faster. To make lettuce water, you simply pour boiling water over romaine lettuce leaves and sip it slowly. The taste has been described as "disgusting" and some people even hold their noses as they sip. Whether or not it's the latest craze on social media,  we took a scientific look at lettuce water, to find out if it's worth drinking, or a big waste of time (and perfectly good salad greens). Here's what we discovered.

Here's Why Lettuce Water Became so Popular

Lettuce water first came into view after a study published by the National Library of Medicine in 2017 that proved lettuce has sleep-inducing effects on mice. This study is referred to and credited in a majority of the lettuce water TikTok videos. However, nutritionists and doctors make it clear that there is no evidence that tells us this works on humans, and some are even going out of their way to tape their own videos, explaining that this drink won't help you sleep faster because it's not "factual."

The study authors wrote that there seems to be a benefit, at least for mice: "The results of this study show that lettuce, especially romaine lettuce, is an interesting and cheap source of sleep-potentiating material and antioxidant polyphenols. The seed and leaf extracts derived from romaine lettuce potentiates the pentobarbital-induced sleeping behavior in mice. Romaine lettuce could provide extracts with sleep-potentiating activity. In addition, the antioxidant polyphenols being used as natural antioxidants of the brain against the oxidative damage could be obtained from these extracts."

Doctors and RDs Debunk the Lettuce Water for Sleep Theory

Plastic Surgeon Dr. Ricky Brown produced a video and said: This stuff won't make you sleep faster, unless your mice," to his 6.7 million followers on TikTok. Dr. Karl also produced his own video and called it, Lettuce Water: Fact or Fiction? and debunked the entire myth. He pointed out that the 2017 study is not accurate for many reasons. In the video, he says: "One they gave mice purified chemical extracts of lettuce, not the actual leaves. Two, they never indicated how long it actually took for the mice to fall asleep, instead, they gave them a drug called pentobarbital which already provides sleep-inducing effects. Third, researchers excluded mice that took too long to fall asleep which skewed the results."

However, there is nothing harmful about drinking warn lettuce water and in fact, there are health benefits, whether or not you add the lettuce. Drinking plain warm water impacts the body differently than drinking room temperature or cold water and has proven science-backed health benefits. And, if you're going to add anything to your warm water, you may want to consider adding a lemon. Or just try plain old water. But drink it warm, not cold.

4 Health Benefits of Drinking Hot and Warm Water. Hold the Lettuce!

When searching whether lettuce water held any magical properties what we found was simply that drinking water (with or without the lettuce or other infusions) was a benefit, especially when trying to lose weight, stay warm, or when you're fighting something off.

1. Drinking 16 ounces of Room Temperature Water Will Boost Metabolism

Everyone wants to speed up their metabolism, and it turns out that water can help here as well. In a study of 14 healthy, normal-weight participants (seven men and seven women), results found that the subjects who drank 500 ml (or 16 ounces) of water increased their metabolic rate by 30 percent within just 10 minutes of drinking, and reached its highest rate of energy production 30 to 40 minutes after drinking. For men, blood "lipids mainly fueled the increase in metabolic rate," and for women, "carbohydrates were mainly used as the energy source." If you're looking to lose weight, that means that drinking a tall glass of water appears to mobilize carbs or fat, depending on your gender, but either way, burning fuel is a benefit.

2. Hot water may help treat cold and or flu symptoms, relieve nasal congestion

If you have a sniffle or stuffed up nose, sore throat, or cold, the mist from a steamy cup of hot water plays a big role in clearing sinuses and treating cold or flu-like symptoms.

In one study, 30 subjects suffering from the common cold or flu were separated into two groups. One group was given hot liquid and the other group was given room temperate liquid. Results suggested that the hot drink provided "immediate and sustained relief from symptoms of runny rose, cough, sneezing, sore throat, chilliness, and tiredness, whereas the same drink at room temperature only provided relief from symptoms of runny nose, cough, and sneezing."

In another study done by doctors in Miami, researchers compared and contrasted the effects of drinking hot water, cold water, and chicken soup on the best way to treat a stuffed-up nose. Results showed that drinking hot water increased how quickly someone could clear their congested nasal passages, "through the nasal inhalation of water vapor," suggesting that hot water is superior to cold water to clear out your nasal passages and get over a cold faster.

3. Drinking Hot Warm Reduces Shivering, Helpful for Spending Time Outdoors

Feeling cold (camping or doing other activity at altitude) to the point where your teeth are chattering or your muscles shivering means your body temperature has dropped from 98.6 to a few degrees below. Shivering is the body's automatic way of producing heat. Whether you're hiking, camping, swimming or just spending time outdoors in the cold, drinking adequate water is extremely important to help your body not lose more heat than it can produce, which results in hypothermia, when the body core temperature drops to 95 degrees or lower and you can suffer organ failure.

When you start to lose heat faster than you can produce it, your nervous system, heart, and other organs can't function properly and this can happen even if your temperature drops just a few degrees. One study suggests that drinking hot water at 126 degrees Fahrenheit helped participants get their body temperature heat up and spend less energy maintaining a healthy, functional state.

4. Warm Water Aids Digestion in Post-Operative Recovery

Drinking warm water helped aid digestion for patients who had undergone laparoscopic surgery to remove their gallbladder. In a study, 60 patients were separated into two groups: The experimental (drinking warm water) and the control group. Results found that patients who drank the warm water after surgery recovered faster and experienced a "favorable impact on intestinal movements." This has implications for anyone undergoing surgery or anesthesia since generally the post-operative norm is to not leave the hospital until you've had a bowel movement, so mothers who have had a C-section and even those patients who have had their appendix out could benefit from drinking in order to move things along.

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