Onion water seems to be all the rage these days. Advocates claim that it is a natural cold and flu remedy that can help the body heal faster and kick symptoms like coughing and congestion. And many consumers who feel threatened by flu, COVID, and various respiratory infections believe them.

But what on earth is onion water? It is precisely what it sounds like: onion immersed in water. Preparation starts with cutting up raw red or yellow onions, placing them into a bowl, and adding water. The fresh onion and water mixture should then soak for about 12 hours. After that, the onion water is ready for consumption.

Besides being a recipe for bad breath, can onion water actually relieve any symptoms, or help the body heal from infections?

A review of the evidence concluded that “effect of onion and its constituents on oxidative stress, inflammatory and immune system were shown indicating their therapeutic value in treatment of various diseases associated with oxidative stress, inflammation, and immune-dysregulation.”

This may sound encouraging but the review was based mostly on pre-clinical evidence, and the question, therefore, remains: are there any good trial data?

Another recent review included clinical trials (where available) and concluded that “possible bronchodilatory and preventive effects of onion and Qt on asthma and other obstructive respiratory diseases. The effects of the plant and its constituents on lung cancer, lung infections, and allergic disorders were also reported both in experimental and clinical studies. However, before preparing drugs based on A. cepa and its constituents for clinical practice, further standard clinical trials are needed to be performed.”

In other words, compelling trial evidence that preparations from onion are effective against viral infections does not exist.

And what about homeopathy?

Homeopaths frequently use potentised onion as a remedy for conditions that cause eyes to water (because ‘like cures like’). Is there any sound evidence that homeopathic onion remedies are better than a placebo? You probably guessed: the answer is NO!

So, no good evidence for onion, potentised onion, onion water, or any other preparations of onion. My advice, therefore, is to continue using your onions in the kitchen rather than in the medicine cabinet.

13 Responses to Onion water for viral infections? (Or just for bad breath?)

  • Perhaps the idea is that no one will come close enough to infect you. Maybe durian fruit would be even more effective.

  • OK, keep it real folks, onion water is unlikely to seriously harm anyone is it? This forum delights in ‘exposing’ anything that’s outside of medical school training. As James Bond famously said in the movie ‘Spectre’ – “Well, it’s all a matter of perspective.”
    To give you one of many examples of medical negligence, here below is the latest stunning report of incompetence and cover up in the medical ‘profession’.

    • “onion water is unlikely to seriously harm anyone is it?

      “Well, it’s all a matter of perspective”

      Perhaps you think about those gullible people [like yourself?] who believe in this nonsense and thus fail to treat a serious infection adequately.

      • Edzard, with the greatest respect, you have no knowledge of what I do or don’t include – in my diet. If you have EVIDENCE and I’m quoting you:
        “Please remember, if you make a CLAIM in a comment, support it with evidence”.
        Your assertion that I am ‘gullible’ is incorrect, ignorant and cannot be backed up by you or anyone else that has no hard evidence of my diet and lifestyle choices. As they say in the movies: “move on, nothing to see here”.
        p.s. – Interesting that you chose not to comment on the example – one of many in recent times – of serious medical misconduct and cover-up which have nothing to do with so called alternative medicine.

    • @Mike Grant
      Your whataboutism is of course stupid, off-topic and irrelevant, but now that you bring it up:
      – Yes, real doctors sometimes make mistakes. And in some cases, doctors even refuse to admit that they did anything wrong, preferring to have everything swept under the rug. This is Not Good.
      – However, mistakes like this are the exception, not the rule – especially the cover-ups. Also, continuous efforts are made to prevent mistakes, AND to have them reported, investigated and corrected in case they do happen after all. Also, changes are often made to prevent mistakes from happening again.
      – The quackery business that you seem so eager to defend OTOH, is built on 100% mistakes. Virtually all of their diagnoses are wrong, and, by inference, so are their treatments. And what’s worse: those quacks will never admit to being wrong, nor will they chastise or oust their peers, not even the ones who really mess things up and kill patients. In all their wilful ignorance, hubris and arrogance, they will ignore all and any evidence that what they are doing is useless at best, and quite harmful at worst.
      – And because the quackery business that you seem so eager to defend will never admit to doing anything wrong, they will also not learn from those wrongdoings, let alone change their modus operandi. They will stubbornly keep on doing things as they have always done, misdiagnosing patients and selling useless treatments, only to be saved by the fact that there is nothing much wrong with 90% of their clientele, and most problems they encounter resolve spontaneously.

      But you were saying?

      • @Richard Rasker

        C’mon Richard…. 90% ? I call BS.

        If that is true, then it’s true for those that visit MD’s also…. no ?
        And if it’s true that 90% have no real medical issues, then how could they be harmed by NOT getting attention from an MD ? … as is so argued so many times here.

        You can’t spin it both ways….lol

        • if a responsible clinician is consulted by a patient who has ‘no real medical issues’ he/she explains this fact to the patient and thus reassures him/her. this ‘attention from an MD’ may be hugely important. Not receiving it can be hugely harmful.

          GOT IT?

          • No Edzard

            Who is consulting any clinician (or MD) that does not have an issue ? The vast majority of the patients have better things to do than spend time and money on imagined physical issues.
            Sure, the physical/mental problem may resolve itself in time…. we know that. But that doesn’t mean it’s not real at the moment.
            Again and again, I will repeat. Patients seek out alternative medicine because they have ALREADY sought out and MD with no resolve, or because they have lost their faith in science-based medicine due to previous failures.

            I do agree that not receiving the care from an MD COULD be harmful, but RR is arguing that at the maximum, it would be only 10% of the cases. Inferring that 90% of cases will resolve themselves in time. Not so for many if not most chronic illnesses.

          • “Patients seek out alternative medicine because they have ALREADY sought out and MD with no resolve, or because they have lost their faith in science-based medicine due to previous failures.”
            I know you don’t understand and don’t care about evidence. In case I am wrong, here is some:

        • @RG

          C’mon Richard…. 90% ? … If that is true, then it’s true for those that visit MD’s also…. no ?

          Yes and no: many people who consult a real doctor also have no serious health problems. I can’t be bothered to dig up the statistics, but IIRC, at least half of all GP consultations involve minor, self-limiting problems.

          However, this percentage will be rather lower than 90% – simply because most people, even those who believe in quackery, are still smart enough to consult a real doctor when they suspect that there might be a serious problem with their health. E.g. people who think that they might have a heart condition will hardly ever turn to a homeopath or the likes as a first course of action (and those with an actual heart condition who do, usually die pretty quickly).
          Most people who consult quacks have vague complaints that aren’t alarming but merely annoying. Quite often, these people consulted real doctors first, who concluded that there isn’t much wrong – or that there is something wrong, but that they don’t have an effective treatment to offer, and that simply ‘wait and see’ is the advice.

          And of course those quacks themselves too much prefer to have customers with whom nothing much is wrong. They just have to patiently listen to these people’s stories (ka-ching), take lots of time expressing their empathy (ka-ching), make up some plausible-sounding ‘diagnosis’ and sell an appropriate ‘treatment’ (ka-ching). And a couple weeks or months and as many consultations later (ka-ching … ka-ching … ka-ching), the problems have resolved on their own – at which point the quack will claim success, and the customer is happy. Usually without realizing that they have been scammed for many hundreds or sometimes even thousands of dollars.

      • You are mis-informed Richard. I have never defended the so called ‘quackery business’ – this silly expression has no legal, scientific or medical definition.
        In fact, many of my colleagues are highly qualified ‘conventional’ physicians including general practitioners, immunologists, virologists and other specialists with qualifications that even you might recognise. If you want to meet or communicate with any of them, then you are welcome to visit our office in Harley Street. Your rant says a lot about you.

    • Mike Grant: As James Bond famously said in the movie ‘Spectre’ – “Well, it’s all a matter of perspective.”

      But Mike, wasn’t it James Beard who said, “I can easily make a whole meal of onion sandwiches?”


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