Evidence Based Symptomatic Relief of Cold and Flu

As the warmth of autumn wanes into winter, individuals steer their attention towards natural medicine interventions to deliver relief from cold and flu symptoms. Evidence-based natural medicines not only promote the resolution of symptoms, but also improve immune resilience and surveillance. Several herbal extracts and nutrients reinforce immune function, offering support to individuals at a higher risk of colds and flu; reducing time lost to fighting infection. As integrative practitioners you are subsequently well positioned to provide comprehensive care for your patients this cold and flu season.

Recognising the window of intervention
Early intervention is critical in buffering the symptoms and severity of infection. As such, it is important to educate patients on the early indicators. Prodromal symptoms including the onset of coughing, sore throat, swollen lymph glands and/or nasal congestion indicate an acute immune response against pathogen exposure. Given the necessity of promptly actioning clinical care, the onset of prodromal symptoms represents an acute window for Practitioners to provide relief for vulnerable patients. Moreover, targeting the initial presentation of cold and flu reinforces immune resilience against circulating pathogens (Figure 1). Indeed, scientific evidence supports a number of specific herbs and nutrients for the management of cold and flu symptoms, offering patients effective strategies against virulent pathogens.

Figure 1: Symptom progression of the common cold and flu.

Symptomatic management of cold and flu
Clinical studies validate the use of natural interventions to provide effective cold and flu symptom relief. A 2017 systematic review of potent immune enhancer, Andrographis paniculata (andrographis), found it significantly relieved the symptoms of acute respiratory tract infection in 33 independent clinical trials.[i] Outcomes of the study included marked improvements in sore throat and cough symptoms, in addition to reducing the amount of sick leave in both adults and children.[ii] Similarly, zinc has been shown to reduce symptoms of respiratory infection. Research conducted by the Cochrane review of 13 clinical trials demonstrates zinc administration within 24 hours of symptom onset reduces the severity and duration of symptoms; with supplementation over five months reducing infection incidence, abseentism and antibiotic prescription.[iii]

Symptomatic management of cold and flu symptoms has also been demonstrated in a randomised clinical trial involving 272 adults supplemented with 500 million colony forming units (CFU) of Lactobacillus plantarum HEAL 9 and Lactobacillus paracasei 8700:2, respectively. These probiotic strains significantly reduced sore throat and duration of symptoms, in addition to reducing the risk of acquiring the common cold.[iv]  Moreover, one billion CFU of Lactobacillus rhamnosus GG (LGG^®) has been shown to reduce the number of upper respiratory tract infections, and lessen the chance of infections lasting longer than three days.[v]  Such data supports the use of strain specific probiotics HEAL9, 8700:2 and LGG^® to increase immune activity as part of a broader protocol to relieve symptoms and offset the symptom severity of seasonal infection.

Defending against infection

While herbal medicines support primary clinical outcomes of symptomatic relief, evidence also supports their use to counter pathogen survival. Sambucus nigra (elderberry) exerts antimicrobial activity against bacterial and viral pathogens, including virulent strains of influenza A and influenza B.[vi] In addition, in vitro research has demonstrated elderberry effectively blocks the DNA replication of infectious bronchitis virus (IBV)[vii] and H9N2 human influenza virus; validating the use of elderberry in reducing the transmissible nature of viral pathogens.[viii] Herbal medicine interventions therefore help to manage the trajectory of cold and flu symptoms, providing patients support against seasonal infectious pathogens.

Improving immune resilience  
Defending against infection can be further enhanced by increasing immune surveillance. Strategies that promote dendritic cell (DC) production up-regulate the detection of viral RNA patterns, and can critically influence the activity of the innate and adaptive immune system within mucosal surfaces.[ix] Research reveals Ganoderma lucidum (reishi mushroom),[x] LGG^®_,[xi] and zinc[xii] all promote anti-infective activity through stimulation and maturation of DCs, resulting in enhanced T cell capacity and secretion of antiviral cytokines. In a clinical trial of 53 nursing home residents, daily supplementation of 30 mg of elemental zinc was shown to enhance T cell number and function.[xiii]  This dose of zinc enhanced serum zinc concentrations, enabling appropriate immune resilience. Ensuring your patients have adequate immune surveillance is an ideal strategy to bolster an effective immune response, helping them defend against viral invasion.

Supporting patients with cold and flu symptoms this winter
Specific immune enhancing agents not only improve immune resilience and surveillance, but also deliver strong, effective relief of cold and flu symptoms. By encouraging proactive symptom management, health providers can prevent the development of acute infections and lessen the impact of evolving viral pathogens. Together, Practitioners and patients can work together to establish a treatment strategy to minimise the risk of infection, reduce the number of days of absenteeism and manage any symptoms that do arise this cold and flu season.

[i] Hu XY, Wu RH, Logue M, Blondel C, Lai LYW, Stuart B, et al. Andrographis paniculata (Chuān Xīn Lián) for symptomatic relief of acute respiratory tract infections in adults and children: A systematic review and meta-analysis. PLoS One. 2017 Aug 4;12(8):e0181780. doi: 10.1371/journal.pone.0181780.

[ii] Hu XY, Wu RH, Logue M, Blondel C, Lai LYW, Stuart B, et al. Andrographis paniculata (Chuān Xīn Lián) for symptomatic relief of acute respiratory tract infections in adults and children: A systematic review and meta-analysis. PLoS One. 2017 Aug 4;12(8):e0181780. doi: 10.1371/journal.pone.0181780.

[iii] Singh M, Das RR. Zinc for the common cold. Cochrane Database Syst Rev. 2011 Feb 16;(2):CD001364. doi: 10.1002/14651858.CD001364.pub3. Review.

[iv] Berggren A, Lazou Ahrén I, Larsson N, Önning G. Randomised, double-blind and placebo-controlled study using new probiotic lactobacilli for strengthening the body immune defence against viral infections. Eur J Nutr. 2011 Apr;50(3):203-10.  doi: 10.1007/s00394-010-0127-6.

[v] Hojsak I, Snovak N, Abdović S, Szajewska H, Misak Z, Kolacek S. Lactobacillus  GG in the prevention of gastrointestinal and respiratory tract infections in children who attend day care centers: a randomized, double-blind, placebo-controlled trial. Clin Nutr. 2010 Jun;29(3):312-6. doi: 10.1016/j.clnu.2009.09.008.

[vi] Krawitz C, Mraheil MA, Stein M, Imirzalioglu C, Domann E, Pleschka S, et al. Inhibitory activity of a standardized elderberry liquid extract against clinically-relevant human respiratory bacterial pathogens and influenza A and B viruses. BMC Complement Altern Med. 2011 Feb 25;11:16. doi: 10.1186/1472-6882-11-16.

[vii] Chen C, Zuckerman DM, Brantley S, Sharpe M, Childress K, Hoiczyk E, et al. Sambucus nigra extracts inhibit infectious bronchitis virus at an early point during replication. BMC Vet Res. 2014 Jan 16;10:24. doi: 10.1186/1746-6148-10-24.

[viii] Shahsavandi S, Ebrahimi MM, Hasaninejad Farahani A. Interfering With lipid raft association: A mechanism to control influenza virus infection by Sambucus nigra. Iran J Pharm Res. 2017 Summer;16(3):1147-1154.

[ix] Ascough S, Paterson S, Chiu C. Induction and subversion of human protective immunity: Contrasting influenza and respiratory syncytial virus. Front Immunol. 2018 Mar 2;9:323. doi: 10.3389/fimmu.2018.00323.

[x] Lin YL, Liang YC, Lee SS, Chiang BL. Polysaccharide purified from Ganoderma lucidum induced activation and maturation of human monocyte-derived dendritic cells by the NF-kappaB and p38 mitogen-activated protein kinase pathways. J Leukoc Biol. 2005 Aug;78(2):533-43.

[xi] Jiang Y, Ye L, Cui Y, Yang G, Yang W, Wang J, et al. Effects of Lactobacillus rhamnosus GG on the maturation and differentiation of dendritic cells in rotavirus-infected mice. Benef Microbes. 2017 Aug 24;8(4):645-656. doi: 10.3920/BM2016.0157.

[xii] Barnett JB, Dao MC, Hamer DH, Kandel R, Brandeis G, Wu D, et al. Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly: a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2016 Mar;103(3):942-51.doi: 10.3945/ajcn.115.115188.

[xiii] Barnett JB, Dao MC, Hamer DH, Kandel R, Brandeis G, Wu D, et al. Effect of zinc supplementation on serum zinc concentration and T cell proliferation in nursing home elderly: a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2016 Mar;103(3):942-51.doi: 10.3945/ajcn.115.115188.