If you haven’t already seen the onion water trend on TikTok, it’s only a matter of time. Across multiple posts, this trend has already accrued well over 200 million views. From speeding recovery from respiratory syncytial virus (RSV), sinus infections, colds, and coughs to helping improve asthma, gut health, and blood pressure, there are many health claims associated with this humble liquid.
Let’s see what the evidence tells us about this trend and hear what some health experts have to say.
Understanding the onion water trend
Onions are so prevalent on TikTok right now that it’s making eyes water. Some are placing halved onions in the corners of their rooms as a natural air purifier, others are stuffing them in their socks overnight when they’re sick, and (of course) others are making them into onion water as a natural immune booster or illness cure-all.
This trend stems from the Dominican tradition of onion tea as a natural remedy. Depending on which TikToker you follow, onion water can be made by cutting up red or yellow onion (never white), mixing it with filtered water, and letting it sit overnight before drinking. Others will boil chopped onion and water together to make their version.
We spoke with two dietitians from different backgrounds on their thoughts regarding this trend. When asked about first impressions of the trend, Bianca Tamburello, RDN at FRESH Communications, shares, “my initial thought was that an onion water concoction is probably not pleasant to the taste buds.” Uh, same.
Brianna Wieser, RDN, LDN, a Mayo Clinic-trained dietitian and Lifestyle Medicine Subject Matter Expert at MOBE, echoes this. “To be honest, the thought of drinking onion water sounds pretty off-putting,” she says. “That being said, the health benefits of onions are well-established in scientific literature, and cultures have used onions for centuries for various therapeutic purposes.”
Health benefits of onions
Interestingly, the onion is one of the most ancient food sources known to historians, with their culinary and medicinal use being traced back to over 5,000 years ago. This member of the allium family has been used as a flavor booster and addition to a healthy diet ever since, and for good reason.
While the green vegetables get all the attention, white vegetables, like onions, have their own unique nutritional benefits. Onions are packed with nutrients like vitamins, minerals, antioxidants, and other plant compounds.
“They offer up vitamin C, a nutrient well known to support a healthy immune system which is important when fighting off a virus or infection,” says Tamburello. Onions are also high in potassium, a mineral and electrolyte that helps to balance fluid in the body, maintain muscle health, and regulate heart rhythms. Plus, onions provide impressive amounts of B vitamins folate and B6, both of which are important for cell growth, energy levels, and optimal metabolism.
One of the most unique nutritional aspects about onions is that they are full of organic plant compounds including antioxidants and flavonoids like quercetin, kaempferol, and organosulfur compounds. In fact, researchers have found that onions contain 25 different flavonoids, making them one of the highest sources in the diet. These plant compounds are super effective in fighting harmful bacteria, reducing inflammation, and eradicating free radicals in the body—bolstering onion’s immune supporting superpowers. Quercetin is also a potent antihypertensive, meaning that it can help reduce and regulate blood pressure in those with hypertension or chronically high blood pressure. It has also been shown to protect the brain to help prevent Alzheimer’s and other neurodegenerative disorders.
The nutrition onions possess translates to improved health outcomes from many different angles. The plant compounds in onions that fight free radicals in the body don’t discriminate, and will actually inhibit osteoclasts (the cells that break down bone tissue) in an extremely beneficial way. One study found that in a study group of women over the age of 50, those who ate onions everyday had five percent greater bone density than those who ate them once a month or less and frequent onion consumption could reduce risk of hip fracture by up to 20 percent.
Other impressive research on onions include:
Onions can even help your gut health (seriously, what can’t they do?). As Wieser explains, “Onions contain prebiotic properties which support a diverse gut microbiome, known to [positively] impact nearly every system of our body.” These prebiotic properties come from the soluble fiber that onions contain, also aiding in healthy digestion.
Should you start drinking onion water?
So, do all these health benefits mean that you should halt whatever you’re doing and whip up some onion water immediately?
One important thing to know is that when it comes to nutrients and plant compounds, some are water soluble while others are fat soluble. This means that these nutrients dissolve into either a water-based or fat-based solution to eventually be absorbed by the body. So for example, if you ate a salad full of healthy fat-soluble vitamins with a fat-free salad dressing and no other source of fat, your body would be missing out on those powerful nutrients.
When it comes to onions, all flavonoids are water soluble, as are B vitamins, vitamin C, and all minerals including potassium. This means that onion water is at the very least on track in that regard, so when onions are in water, they will leach these nutrients into the water to create a nutrient-rich beverage that may have a positive impact on your health.
However, it’s vital to look at the whole picture. “Despite the health benefits of the onion, our body’s ability to heal and recover from illness has far more to do with our daily lifestyle habits like overall nutrition, physical activity, sleep, and stress management than drinking a glass of onion water when we are feeling sick,” Wieser says.
When looking at the trend from a safety perspective, Tamburello shares, “Drinking onion water poses little to no risk for those who are curious to test it out, however, it’s important to see a doctor when you’re not feeling well to ensure your health needs are fully addressed with research-based treatment.”
So while onion water certainly won’t hurt your health, there isn’t “any research that supports the effectiveness of onion water in speeding recovery from RSV, sinus infections, or colds,” says Tamburello. It’s also important to note that TikTok has been a hub for health misinformation in the past, so as with every health claim you see on social media, be sure to do your research.