Notes and references
Echinacea
– one systematic review concluding possibly tiny benefit https://pubmed.ncbi.nlm.nih.gov/31126553/ and older Cochrane review similar https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000530.pub3/full
but studies were overall variable, selectively reported, poorly completed and not clinically significant
theoretical reasons as to why *might* work https://www.sciencedirect.com/science/article/pii/S2589936821000396
“Our review presents evidence that echinacea might have a preventative effect on the incidence of upper respiratory tract infections but whether this effect is clinically meaningful is debatable.”
but no real world impressive benefits, so it’s a no from me
Vit D
– gov recommend that people take it https://www.gov.uk/government/publications/vitamin-d-supplementation-during-winter-phe-and-nice-statement/statement-from-phe-and-nice-on-vitamin-d-supplementation-during-winter
however that recommendation has been controversial for years ….
low vitamin d levels -> associated with more URTIs esp in people with asthma/COPD https://pubmed.ncbi.nlm.nih.gov/19237723/ (2019)
supplementing with vitamin d-> small decrease in URTIs https://www.bmj.com/content/356/bmj.i6583.long however 33 people need to take vitamin D to prevent one RTI and much more effective in people who were very deficient in vitamin D (BMJ 2017)
that was then followed by 2 rapid reviews by NICE and SACN which concluded no evidence benefit to population in taking vit D to prevent RTIs
https://assets.publishing.service.gov.uk/media/5fd7a2cbe90e076630958ede/SACN_June2020_VitaminD_AcuteRespiratoryTractInfections.pdf; they pointed out that the ” systematic review by Vuichard Gysin et (2016) included only healthy populations and reported that vitamin D supplementation did not reduce the risk of ARTIs”, however the Martineau group are sticking by their conclusions in 2021 https://www.thelancet.com/journals/landia/article/PIIS2213-8587(21)00051-6/fulltext
SACN concluded that the evidence on vitamin D supplementation and infection risk (ARTIs and tuberculosis) was inconsistent and generally did not show a beneficial effect of vitamin D supplementation on infectious disease risk.
bottom line: *may* have a small protective effect, probably most in the most deficient people, but is it worth the trouble?
Multivitamins
No; and Vitamin C https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD000980.pub4/full review doesn’t justify big claims.
Turmeric
some theoretical reasons why – some antimicrobial properties –https://pmc.ncbi.nlm.nih.gov/articles/PMC7693600/ – but where is the evidence for real world human benefit? very little, eg https://www.tandfonline.com/doi/full/10.1080/19390211.2023.2185723#abstract
Ginger shots
again some molecular theory as to why it might work https://pmc.ncbi.nlm.nih.gov/articles/PMC7644455/ but absence of advantage in ‘immunity’ /preventing or treating URTI. some evidence for nausea/vomiting pregnancy/post op nausea . But not on immunity https://pubmed.ncbi.nlm.nih.gov/38903613/
First Defence
claim “Vicks First Defence is a medical device, here to help you in the fight against common cold viruses. You can use it at first signs of a cold to help reduce the risk of developing a full blown cold or you can even start using it when exposed to cold viruses….If you are still in the first 36 hours of the cold, Vicks First Defence will help inactivate the cold virus. After 36 hours, the virus has probably developed into a full blown cold.”
https://www.vicks.co.uk/products/early-cold-treatments/vicks-first-defence-nasal-spray
Yes ! but also no.
Large well done RCT published in Lancet https://www.thelancet.com/journals/lanres/article/PIIS2213-2600(24)00140-1/fulltext
adults with at least one risk factor for adverse outcomes of URTI (eg obese, asthma, COPD, diabetes)
randomised to either vicks spray (polymer+buffer)/ saline spray/ behavioural intervention (physical activity/stress management)
told to use spray up to 6 times a day at first sign cold and 2 days after symptoms gone, after potential exposure to infection, or in contact with someone else with symptoms. Self reporting:
over 6 months: usual care 8.2 days illness, saline 6.4 days, gel 6.5 days, behavioural 7.4 days.
if reported an illness, usual care 15.1, saline 11.8, gel 12, behavioural 14.2 days.
“We have not been able to confirm the superiority of gel-based spray compared with saline spray. In our study, both sprays had almost identical impact:“
also generated a reduction in antibiotic use.
Fermented foods / the role of the gut microbiome
many claims, reasonable theory https://pmc.ncbi.nlm.nih.gov/articles/PMC8147091/ but where is the actual evidence ?
https://www.sciencedirect.com/science/article/pii/S2772753X23002034
massive hype on this for several years but where is the data?
Exercise
nice overview
https://pmc.ncbi.nlm.nih.gov/articles/PMC7127736
For adults, regular exercise may reduce the overall severity of acute respiratory tract infections and the number of days with symptoms, but there is no evidence that exercise reduces the overall occurrence or duration of these infections.1 (Strength of Recommendation: B, based on inconsistent or limited-quality patient-oriented evidence.)
Exercise did not reduce the number of ARI episodes, proportion of participants experiencing at least one ARI during the study, or the number of symptom days per episode of illness. …
Regular exercise has been reported to enhance immune cell activation https://www.sciencedirect.com/science/article/pii/S2666337624000040#sec4
https://www.sciencedirect.com/science/article/pii/S2666337624000040#sec4
Conclusions and Relevance In this cohort study of adults aged 45 years or older, those who adhered to PA guidelines before the pandemic had lower odds of developing or being hospitalized for COVID-19. Thus, higher prepandemic PA levels may be associated with reduced odds of SARS-CoV-2 infection and hospitalization for COVID-19
but cohort – can’t tell cause or effect
https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2814993
and
moderate-intensity cardiovascular exercise executed three times per week for 4 months, prior to viral exposure, improved influenza vaccination responses, with extended duration of antibody levels in older adults
cardiovascular exercise resulted in a significant increase in seroprotection 24 weeks after vaccination (30–100% dependent on vaccine variant), whereas flexibility training did not
Although weekly performed aerobic workouts may have a more pronounced impact on the adaptive immune system than low-impact exercises, both still affect immune regulation in healthy individuals.
Comments are closed.