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.
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.
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.