The amount of different so-called alternative medicines (SCAMs) that are being tried or promoted against COVID-19 is legion. Anything really from vitamins to herbal remedies, homeopathics to chiropractic. In fact, it is hard these days to find a SCAM that is not touted for COVID-19.

This study aimed to evaluate if a dietary supplement of quercetin (a polyphenol contained in many fruit and vegetables), vitamin C and bromelain (a proteolytic enzyme contained in pineapple) could be protective against coronavirus infections.

In the verum group, a supplement containing

  • 500mg of quercetin,
  • 500mg of vitamin C,
  • 50mg of  bromelain (QCB)

was administered daily in 2 divided doses for 71 healthcare workers working in areas with high risk of COVID-19, whereas 42 were the control group who received no supplements. The maximum period of follow-up was 120 days. Termination of QCB use prematurely or having a coronavirus infection was the end of a volunteer’s study participation. A rapid diagnostic test was used to detect immunoglobulin positivity.

Graphic demonstrated survival without COVID-19 during follow up time between groups

Graphic demonstrated survival without COVID-19 during follow up time between groups

A total of 113 persons were included. No significant difference were detected between groups at baseline. Mean age of QCB group was 39.0 ± 8.8 years and control group was 32.9 ± 8.7. Average follow-up period for the QCB group was 113 days, and for the control group, 118 days. During the follow-up period, 1 healthcare worker in the QCB group and 9 out in 42 in control group contracted COVID-19. One case was asymptomatic, while others were not. Transmission risk hazard ratio of participants who did not receive QCB was 12.04 (95% Confidence interval= 1.26-115.06, P = 0.031). No significant effect of gender, smoking, antihypertensive medication exposure and having chronic disease on rate of transmission. The authors concluded that this study revealed that QCB was protective for healthcare workers.

The sudy is so poorly written and reported that I had trouble making sense of it. In fact, I first thought it was a fake. Then I saw this note:

Preprints with The Lancet is part of SSRN´s First Look, a place where journals identify content of interest prior to publication. Authors have opted in at submission to The Lancet family of journals to post their preprints on Preprints with The Lancet. The usual SSRN checks and a Lancet-specific check for appropriateness and transparency have been applied. Preprints available here are not Lancet publications or necessarily under review with a Lancet journal. These preprints are early stage research papers that have not been peer-reviewed. The findings should not be used for clinical or public health decision making and should not be presented to a lay audience without highlighting that they are preliminary and have not been peer-reviewed.

If the results are for real (because of the small sample size, the lack of a placebo-control, dozens of potential confounders, etc., the findings could easily false-positive), they would merit urgent replication in a larger, more rigorous trial.

And meanwhile?

Meanwhile I would be very sceptical about the validity of the results. The paper (it really is just a submission for publication in the Lancet; I am not even sure that it will be officially published and I don’t quite see why it is being made available to the public in this way) is too flimsy for words. Despite these warnings, it is likely that many consumers will fall for the claim that QCB was protective for healthcare workers. 

9 Responses to Does a dietary supplement (quercetin, vitamin C, bromelain) reduce the risk of COVID-19 infections?

  • The authors appear to have no grasp whatsoever of mathematics. They report the mean age rather than the median, and give a range without specifying what they mean by that. Then they talk about average follow-up period, average being a non-technical term which is understood differently by different people. When they are talking about hazard ratios they report a confidence interval to five significant figures, a ludicrous and unjustifiable degree of precision. It is quite clear that they don’t understand any of these basic concepts.

    It is also not clear whether the treatment allocation was randomised – since they don’t mention randomisation we have to assume that it wasn’t. The sample sizes were also fairly small.

    The only conclusion that I can draw from this study is that the authors urgently require training in how to conduct medical studies.

    The use of the term average in this context puts me in mind of the BBC quiz show University Challenge (which I always enjoy, though I am no longer quick-witted enough to answer the questions that require rapid calculations). The “average” age of each team is given, which appears to be the mean, alhough that doesn’t really describe the players very well, as an average age of 24 could mean that they are all post-graduate students, or that they are all undergraduates and one of them is a mature student. Mind you, the quizmaster, Jeremy Paxman, while entertaining is clearly only half-educated, as he appears to be scientifically illiterate.

    • There are countless studies that don’t measure up to the high standards that some health professionals and academics require. This one just happens to be looking at the potential to counter the covid-19 virus. So I find it strange this flawed study even appears on this illustrious forum, what’s the point? …..
      Ahh, just realised why, as Edzard commented :
      “In fact, it is hard these days to find a SCAM that is not touted for COVID-19”.

      So why are you wasting your valuable time Edzard seeking out these so called SCAM type studies? How about being more positive and featuring well designed studies of groups of covid patients that demonstrate significant benefits when using certain nutrients compared to baseline. Are you really saying that Vitamin D, C, Zinc, Selenium, Magnesium and many other NON-SYNTHETIC naturally derived compounds have no value or provide no useful support for the immune system?

      • “So why are you wasting your valuable time Edzard seeking out these so called SCAM type studies?”
        It’s called informing the public, and I happen to believe that, in the realm of SCAM, this is important.
        “How about being more positive and featuring well designed studies of groups of covid patients that demonstrate significant benefits when using certain nutrients compared to baseline.”
        I’d do this with pleasure! Do you know of any?

  • There are good reasons to research further on quercitin/zinc as an antiviral therapy. Of the hundreds of papers on the various topics those below are a quick selection:

    Zinc Antiviral Activity:

    The Role of Zinc in Antiviral Immunity

    Zinc Deficiency:

    Globally, 17.3% of the population is at risk for zinc deficiency due to dietary inadequacy; up to 30% of people are at risk in some regions of the world

    Zinc Ionophores:

    Zinc Ionophore Activity of Quercetin and Epigallocatechin-gallate: From Hepa 1-6 Cells to a Liposome Model

    Zinc-COVID-10 Perspective:

    The Potential Impact of Zinc Supplementation on COVID-19 Pathogenesis

    • There certainly do seem to be good reasons to build on these in-vitro and animal studies to investigate a potential therapeutic role here in humans. Sadly the trial that Edzard was looking at was so badly designed that it has been unable to contribute anything much of value here.

      History has taught us the dangers of extrapolating from non-human investigations to clinical practice and overlooking this vital step.

  • As a non medical person , but somebody that can read medical papers there are lots of cheap natural substances that could potentially be of use in combating COVID-19 but although lots of them have been suggested for investigations and trials it seems to me that hospitals and the people running them are so in the pockets of large pharmaceutical companies that none of these substances are being tested . There are lots of trials of expensive experimental drugs some with severe side effects from pharmaceutical companies financed by them going on in our hospitals , but not as you say quercitin, bromelain,Artemisinin, Curcumin, etc etc and so these are being dismissed as quackery by the very medical institutions (WHO) being financed by these pharmaceutical giants its one big racket.

    • There is nothing extraordinary happening in the industry, really. The issue with “cheap substances that could be potentially of use” is that they are not of use, really. The reason that funding primarily goes to stuff that are truly “of use”, like monoclonal antibodies, is that they are provably effective. It is this proof of efficacy that costs huge amounts of money and vitamin c does not really have a record of use for almost anything else than, well, not dying from deficiency.

      Mapping the pathways and interactions involved in the pathogenesis of a disease is an enormous task and people that do it are literally lab ghosts, sweating over centrifuges, triple-checking numbers and results, over months to years. Progress is done in, literally, baby steps. Almost each paragraph regarding some random disease in a medical textbook has necessitated multiple years of research before becoming “common” medical knowledge. Then, decades after standing on the shoulders of underpaid giants, what we have is no less than an actual map, and we can then identify where we may want to attack. Then, exploiting another pile of accumulated mountains of evidence and methods, we can synthesize targeted “biological factors” to interfere with a single location in this map.

      What you are suggesting is that the “powers that be”, with their thirsty financial motives, spending billions to trillions in research, would not really be so smart or capable, as to take something like Vitamin C and charge it 100£ per bottle, for example, to make money from something that they can produce much cheaper and easier. It is a piece of cake for them, but they don’t, because money is not the primary motivation, nor has it ever been. It is a game of power, where the main manifestation of vanity is excellence. You have to be the best. You want to be known as Pfizer, “the company that saved the world from mass destruction” (and Moderna, Johnson & Johnson and others, this post is not about sides obviously).

      In order to be the best, they invest on knowledge and science, the sure-fire way! They don’t invest in Vitamin C research because they know from past analyses that there is virtually no plausible interaction that could help in treating COVID-19. On the contrary, remember monoclonal antibodies, I mentioned above? Take a look at this official source for high-risk COVID-19 positive patients. Read to the end, it has insightful information if you want to know more about MABs. Let me also copy from the source:

      There is no cost to anyone for the antibodies themselves, but there may be treatment fees. If you do not have insurance, ask the facility if there will be a charge.

      Right… after you finish reading up on it, try to take a look at how much this type of medication normally costs. From what I read here, it’s about 2,400$ per dose. That is a lot of money not to make from your primary target group, isn’t it? Which brings us to another difference between conventional medicine and SCAM modalities. SCAM typically targets the individuals themselves for its income instead.

    • @Joe Public

      You are very brave and willing to talk about cheap alternatives to big-pharma drugs that big-pharma doesn’t want us to know. You are right in that everyone is in the pockets of bigpharma, except for non-medical people like you and me. I do my research by watching YT videos and reading medical journals and there is a lot of knowledge out there that bigpharma doesn’t want you to know.

      You’d be surprised to know that a cheap alternative to experimental COVID cures that bigpharma wants us to pay big bucks for is literally bullshit. You don’t believe me? Well then how did this guy: cure his terminal cancer with cowpathy? A therapy that involves ingesting all kinds of bovine by products including bullshit. This is exactly what bigpharma doesn’t want you to know Joe. Cowpathy is complete safe and natural and has been used for centuries in India to cure various diseases, here is a video that you should watch:

      I have been researching cowpathy on my own and came up with an immunization protocol for COVID and I have been using it for a year now and I never caught covid, I don’t wear a mask and never got vaccinated. The protocol is very simple, it involves smearing one’s body from head to toe with fresh steaming pile of bullshit first thing in the morning. Then one would go about their business and wash it all off in the evening. Sure, you may smell bad but who cares? You have got a cheap and natural way to ward of disease and it is not manufactured by bigpharma. You might say quercitin, bromelain, artemisinin, Curcumin etc. etc. are also natural. But Joe, those supplements are manufactured in a lab or factory where the naturally existing chemicals are extracted using various chemical processes and are not as pure as the bullshit that is harvested directly from the rear-end of a cow.

      I have a business called Bullshit Cures LLC and I will ship you a fresh steaming pile of bullshit everyday no matter where you are in the world. I am willing to ship you a 5-day supply for free, just pay shipping and handling. I also sell bullshit pills and suppositories, that are guaranteed to feed your ego from both ends and you will be full of shit in no time. Would you like to find out the wonders of natural bullshit that has been used for centuries as medicine? Or would you like to keep paying bigpharma loads of money for their so-called pharmaceuticals that are designed to be addictive? What’s it gonna be Joe Pubic?

  • “there are lots of cheap natural substances that could potentially be of use in combating COVID-19”

    List them. Make sure you describe the prior plausibility and relevant evidence for each.

    Also, don’t forget: cotton masks are cheap and natural. Vaccines are cheap and natural†. And both of those already have robust evidence behind them. So perhaps you can also explain why the “cheap and natural” crowd take such vociferous objection to those cheap and natural—and also effective—products. Might it be because they don’t profit for them, whereas they make a mint selling fancy little bottles of your “cheap and natural” (and frequently useless) substances at swanky boutique prices?

    † Vaccines train the immune system, which is natural, by exposing it to a harmless fragment of the disease, which is also natural. The only bit that isn’t entirely natural is the manufacturing, but the same is just as true as bottles of vitamin pills; and the vaccines end up being a lot cheaper too.

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