World Naturopathic Federation (WNF) - Rapid Reviews of herbs & nutrients and their benefit in upper respiratory tract infections (URTI)
Naturopathic researchers associated with WNF have produced 'Rapid Reviews' on a range of nutrients and herbs in regards to their effect in URTIs published in "Advances in Integrative Medicine" which can be found on Science Direct (the world's leading source for scientific, technical, and medical research). Commentary on these reviews can be found below:
World Naturopathic Federation (WNF) Commentary: Rapid Reviews
By Dr. Iva Lloyd, ND and Dr. Amie Steel, ND, PhD
At the time of writing this commentary, knowledge on the pathogenesis of SARS-CoV-2 and how to effectively treat it is lacking. The role of naturopathic treatment approaches or those from the realm of Traditional and Complementary Medicine (T&CM) have received limited attention with respect to their potential role in this pandemic.
Based on contemporary research evidence, traditional knowledge and the extensive training and experience of naturopathic doctors (NDs) in pharmacognosy, herbal medicine and clinical nutrition there is reason to believe that naturopathic approaches warrant consideration among the span of possible aids to the global response to COVID-19. Hence, the naturopathic profession undertook the task of conducting rapid reviews to assess the role of specific recommendations in the prevention or treatment of upper respiratory tract infections (URTIs) inclusive of, but not limited to, COVID-19. The focus of all rapid reviews was limited to human studies specific to URTIs either as original research or systematic reviews.
With the support of nine naturopathic educational institutions which included a team of over 40 naturopathic researchers, practitioners and content experts from seven countries and five WHO world regions, in two short months the profession has produced ten rapid reviews related to the role of natural health products in treating acute respiratory tract infections, with a further two reviews in draft.[i] These rapid reviews will be published individually and as a dedicated issue of the scientific journal Advances in Integrative Medicine (Elsevier publication). They will be made open-access – meaning they will be free for download. The Task Force was chaired by WNF President Dr Iva Lloyd, ND with Dr Amie Steel, ND PhD and Professor Jon Wardle, ND,MPH, LLM, PhD as research leads.
The following is a brief overview of the findings from the completed reviews:
Research Focus: Brief Overview of Findings
Vitamin C [ii]
Oral vitamin C may assist with the symptoms of acute respiratory viral infections (ARI) and common cold-induced asthma, but no studies have been identified justifying oral vitamin C for the prevention or treatment of coronavirus infections including COVID-19. When taken at onset of ARI, oral vitamin C may reduce the duration of symptoms including fever, chest pain, chills and bodily aches and pains. It may also reduce the incidence of hospital admission and duration of hospital stays. For individuals admitted to hospital with community-acquired pneumonia, vitamin C may improve respiratory function in more severe cases. No major adverse events nor interactions were reported by either method of administration. However, there is an absence of high quality, contemporary clinical research examining this topic. Current evidence suggests further studies are needed to better understand the value of both oral and IV vitamin C for ARI, including COVID-19.
Vitamin D [iii]
Experimental evidence and observations in large cohorts are generally consistent that deficiency and insufficiency of vitamin D is associated with increased risk of ARTI, and supplementation for those with deficiency/insufficiency may lead to clinically meaningful reductions in the incidence of ARTI. Based on significant heterogeneity in published clinical trials there is however, insufficient evidence to draw conclusions regarding the impact of vitamin D supplementation on the severity or duration of ARTI, nor on outcomes related to lung injury or hospitalization from ARTI.
Based on the available evidence, multivitamin supplementation does not appear to reduce the incidence of ARTI or mortality (both ARTI-related and all-cause). The effect of multivitamins taken before infection on the duration of ARTI is unclear due to conflicting results across studies. Multivitamins may, however, reduce the symptoms associated with ARTI such as headache, conjunctivitis, and activity restriction but not the overall symptom scores.
Zinc may potentially reduce the risk of SARS-CoV-2 infections and shorten the duration and severity of illness, including recovery from stroke, through several mechanisms. Indirect evidence from systematic reviews have found zinc supplementation is effective for the prevention of acute respiratory infections in young children and zinc lozenges may reduce the duration of the common cold in adults. Safety concerns associated with high doses or prolonged intake of zinc include anosmia (loss of smell) and copper deficiency.
Current evidence on the efficacy of quercetin supplementation in the treatment and prevention of COVID-19 is insufficient for its clinical recommendation at this time. Quercetin exhibits both immunomodulatory and antimicrobial effects in preclinical studies; however, only three human clinical trials, each with a low risk of bias rating, were identified in this rapid review. One study reported a decrease in incidence of upper respiratory tract infections following a competitive athletic event. A larger community clinical trial reported a benefit in older, athletic adults only.
Current evidence suggests that N-Acetyl Cysteine (NAC) administration may help improve outcomes in people with acute respiratory distress syndrome (ARDS) and acute lung injury (ALI) – conditions that closely resemble the signs and symptoms of COVID-19. In this rapid review, NAC was predominately administered intravenously to patients with ARDS or ALI, who were at risk of or requiring mechanical ventilation, and were admitted to a hospital intensive care unit. Findings indicated that NAC administration may assist in improving markers of inflammation or oxidation, systemic oxygenation, the need for / duration of ventilation, rate of patient recovery and clinical improvement score. The effects of NAC on patient length of stay, CT/x-ray images, mortality rate and pulmonary complications were inconclusive.
Essential Oils [viii]
Clinical evidence from published clinical trials identified in this rapid review suggests that oral administration of blends of certain essential oils (EO) can reduce symptoms of acute respiratory infections of viral origin in humans, namely acute sinusitis and acute bronchitis.
Sambucus nigra (Elderberry) [ix]
Collectively the evidence obtained from across five clinical studies involving 996 adults indicate that mono-herbal preparations of Sambucus nigra L. berry (S.nigra), when taken within 48 hours of onset of acute respiratory viral infection, may reduce the duration and severity of common cold and influenza symptoms in adults. There is currently no evidence to support the use of S.nigra berry for the treatment or prevention of COVID-19. Given the body of evidence from preclinical studies demonstrating the antiviral effects of S.nigra berry, alongside the results from clinical studies included in this review, further pre-clinical research exploring the potential role of S.nigra berry for the prevention and/or treatment of COVID-19 infection is encouraged.
Echinacea spp. (Echinacea) [x]
Echinacea supplementation may assist with the symptoms of acute respiratory infections (ARI) and the common cold, particularly when administered at the first sign of infection; however, no studies using Echinacea in the prevention or treatment of conditions similar to COVID-19 have been identified. Previous studies have reported that Echinacea may decrease the severity and/or duration of ARI when taken at the onset of symptoms. The studies reporting benefit used E. purpurea or a combination of E. purpurea and E. angustifolia containing standardized amounts of active constituents.
Hedera helix (Ivy Leaf) [xi]
Based on the evidence identified in this rapid review, Hedera helix preparations and herbal complex preparations including H. helix may be a therapeutic option for treating early symptoms of respiratory tract infections. The best effectiveness for H. helix preparations has been proven for coughing, as an expectorant and to reduce the frequency and intensity of cough. Only weak evidence was found for all other researched symptoms. Both adults and children tolerate H. helix well. Currently, there is insufficient evidence to recommend the use of this supplement in the treatment or prevention of COVID-19. However, the current evidence justifies further research to better understand its applicability in coronavirus infections.
Table 1: Brief Overview of Findings from Rapid Review of Evidence Reported in Advances in Integrative Medicine Volume 7, Issue 3 (Elsevier).
These rapid reviews demonstrate the naturopathic profession’s dedication to evidence-informed decision making and their commitment to being part of the solution to this global pandemic.
[i] World Naturopathic Federation, Rapid Reviews: http://worldnaturopathicfederation.org/wnf-covid-19-task-force/ Accessed July 20th, 2020
[ii] Rapid review of Systematic reviews on the efficacy and safety of Vitamin C in the management of Acute Respiratory Infection and Disease. Authors: Janet Schloss, Romy Lauche, Joanne Harnett, Nicole Hannan, Danielle Brown, Tom Greenfield, Amie Steel.
[iii] The effects of Vitamin D on acute viral respiratory infections: a rapid review. Authors: Ryan Bradley, Janet Schloss, Danielle Brown, Deisy Celis, John Finnel5, Rita Hedo, Vladyslav Honcharov, Traci Pantuso, Hilda Pena, Romy Lauche, Amie Steel
[iv] Multivitamins for acute respiratory tract infections: a rapid review. Authors: Holger Cramer, Nicole Hannan, Janet Schloss, Matthew Leach, Iva Lloyd, Amie Steel
[v] Clinical significance summary: preliminary results of a rapid review of zinc for the prevention and treatment of SARS-CoV-2 and other acute viral respiratory infections. Authors: Susan Arentz, Guoyan Yang, Dr Joshua Goldenberg, Jennifer Beardsley, Stephen P Myers, Dominik Mertz, Stephen Leeder, Jennifer Hunter
[vi] The effect of quercetin on the prevention or treatment of COVID-19 and other respiratory tract infections in humans: a rapid review. Authors: Monique Aucoin, Kieran Cooley, Paul Richard Saunders, Valentina Cardozo, Daniella Remy, Holger Cramer, Carlos Neyre Abad, Nicole Hannan
[vii] The effects of N-Acetyl Cysteine on acute viral respiratory infections in humans: a rapid review. Authors
Janet Schloss, Matthew Leach, Danielle Brown, Nicole Hannan, Penny Kendall-Reed, Amie Steel
[viii] Effects of essential oils on symptoms and course (duration and severity) of viral respiratory infections in humans: A rapid review. Authors: Sebastian Prall, E. Joy Bowles, Kathleen Benett, Carolyn Giselle Cooke, Tamara Agnew, Amie Steel, Tina Hausser
[ix] The effects of Sambuccus nigra berry on acute respiratory viral infections: a rapid review of clinical studies. Authors: Joanna Harnett, Kerrie Oakes, Jenny Carè, Matthew Leach, Danielle Brown, Holger Cramer, Tobey-Ann Pinder, Amie Steel, Dennis Anheyer.
[x] The effect of Echinaceaspp. on the prevention or treatment of COVID-19 and other respiratory tract infections in humans: a rapid review. Authors: Monique Aucoin, Kieran Cooley, Paul Richard Saunders, Jenny Carè, Dennis Anheye, Daen N. Medina, Valentina Cardozo, Daniella Remy, Nicole Hannan, Anna Garber
[xi] The effects of Hedera helix on viral respiratory infections in humans: a rapid review. Authors: Larisa AJ Barnes, Matthew Leach, Dennis Anheyer, Danielle Brown, Jenny Carè, Romy Lauche, Daen N Medina, Tobey-Ann Pinder, Andrea Bugarcic, Amie Steel.