Infections are part of the human condition and have coexisted with us since the dawn of time. The positive side of this equation is their essential role in the development of our immune system; the negative side is that they can make us very ill and at times be life-threatening.

How we respond to infection (how ill we become) depends on how virulent the organism is; the strength of our immune systems and the portal of entry of the organism (for example, the skin, the nose or the mouth) and how effective the barrier mechanisms are at these sites; and how effective are the various components of our blood-borne immunity.

If the organism is particularly virulent, the immune system can be overwhelmed but, if the immune system is healthy, the person may suffer only mild symptoms (if any) while at the same time developing antibodies to — and, therefore, future protection from — that particular organism.

Flu epidemics usually occur about every three years and are commonly caused by influenza A.

Colds and influenza have adversely affected humans since antiquity. Even the ancient Egyptians had a specific hieroglyph for the disease and Hippocrates the Greek physician described the disease in the 5th century BC. The term cold probably derived from the ancient physicians who described “cold” conditions and “warm” conditions. Despite all our medical knowledge today, treatments have barely advanced since ancient times and today respiratory infections are the leading causes of death for children under the age of five and complications from them are a significant cause of death in the elderly.

The cold is the commonest infectious disease that humans contract and it is today an economic as well as health nightmare. Respiratory disease results in significant losses to the economy in lost workdays and school attendance and the medical costs are huge. In Australia, costs to business were calculated from January to September in 2017 (with the flu season not yet over for the year) at $114.6 million in lost productivity.

Colds and flu are the leading cause of doctor visits in Australia annually and influenza infections are the leading cause of morbidity and mortality: 13,500 hospitalisations and more than 3000 deaths per year among Australians over 50 years of age, which is double the number of deaths from motor vehicle accidents.

Colds and influenza: similar but different

While there is a significant overlap in the diagnosis and symptoms of colds and flu, both are caused by viral infections — albeit different viruses. The most common initial symptoms of a cold are headache, sneezing, chilliness and sore throat, followed later by nasal discharge and/or obstruction, sinus pain, coughs (if the infection spreads to the lungs or a secondary infection develops because of the lowered immunity) and general malaise.

The severity of symptoms increases quickly over two to three days after the initial infection, lasting about seven to 10 days with some symptoms persisting for more than three weeks. A lingering cough is the largest single cause of medical consultations.

At least one third of the annual visits to a medical doctor to treat colds and flu result in a prescription for antibiotics even though they have no effect on viral infections and can lead to the development of antibiotic resistance.

Viral infections

Cold

The common cold — or acute viral nasopharyngitis — is usually a mild self-limiting infectious disease that can be caused by more than 100 different viruses, rhinoviruses (50 per cent) and coronaviruses (20 per cent) being the most common causes and influenza viruses and adenoviruses accounting for the rest. Influenza viruses account for 5–15 per cent of colds.

Rhinoviruses are small non-enveloped single-stranded RNA viruses that are largely responsible for “head colds” and proliferate in cooler parts of the body (the lungs and gut are warmer and therefore do not support rhinoviruses). They spread by person-to-person contact, inhalation and contact with contaminated surfaces. The virus expresses in bodily fluids including sweat.

Infected cells release inflammatory molecules, which increase vasodilation and permeability, leading to nasal congestion, rhinitis and sneezing. Stress and allergic conditions (these are inflammatory) affecting the nose and throat increase susceptibility to these infections.

Influenza

Influenza is generally more severe than the common cold and is an acute respiratory illness caused primarily by the influenza viruses A and B and occasionally C. It occurs worldwide and is responsible for significant morbidity and mortality, particularly in epidemics — the first of which ever recorded was in 1173–74, so they are not a new phenomenon.

Epidemics usually occur during the winter months and in epidemic years up to 10 per cent of the population can be affected. The elderly, young children under two years old and people with immune disorders experience the highest rates of serious illness and death. Flu epidemics usually occur about every three years and are commonly caused by influenza A. The last epidemic — the swine flu called H1N1 virus — was in 2009.

Plant medicines act more as a broad-spectrum antimicrobial/antiviral treatment as they stimulate the immune system to respond to the specific organism naturally.

The influenza A virus was first isolated from humans in 1933 and subsequent studies have shown that it mutates rapidly, creating problems for medical treatments. Of the two types, infection from influenza A occurs more frequently and is more dangerous to humans. Influenza B usually produces milder symptoms and does not mutate as readily. A third type, the respiratory syncytial virus, also causes an influenza-like illness.

Influenza is most likely to manifest as a sudden-onset fever with headaches, cough, sore throat, myalgia (muscle pain), weakness and loss of appetite. It is potentially a serious illness and can be life threatening.

The influenza virus mutates annually, which is why it is so difficult to prevent and/or treat medically. The advantages of herbal medicines and nutrients are that they have different actions from pharmaceuticals in the human body. They do not directly kill the pathogen but instead stimulate the body’s defence mechanisms (natural killer cells, T cells etc), so the immune system strengthens to deal with the challenge.

This activity is not dependent on determining the exact pathogen because plant medicines act more as a broad-spectrum antimicrobial/antiviral treatment, as they stimulate the immune system to respond to the specific organism naturally and then program itself for the future protection of the individual, generating antibodies to prevent subsequent infections by the specific organism.

However, even with plant medicines, the immune system cannot predict the ability of the virus to mutate, so annual treatments are recommended.

Bacterial infections

Viral infections can enhance susceptibility to bacterial infection by impairing the innate immune defence mechanisms of the respiratory tract through various pathways. Bacterial infections are therefore more likely to be secondary infections and more a complication of the immune challenge rather than the initial infection. Pneumonia, for example, is a life- threatening illness and is commonly a secondary infection to the flu.

Signs and symptoms

The symptoms of colds and influenza are variable, influenced by the nature of the infecting virus but modulated by age, stress levels and the host’s immune status. Depending on these factors, most commonly the disease may occur with no obvious symptoms as an acute self-limiting illness or, in severe cases, may even kill the host. It is the immune response of the body to infection that generates the symptoms.

Psychological effects

The mood changes associated with colds and flu are thought to be triggered by the effects of inflammation on the central nervous system. Colds and flu lead to a reduction in alertness, depression, anxiety, irritability, lack of motivation, impaired concentration, sleep alterations, anorexia and confused states. These can continue for a few weeks afterwards.

Anorexia is interesting. The folklore advice to “feed a cold and starve a fever” has some basis in physiology. Evidence indicates that acute anorexia (lack of appetite) in response to infection is beneficial and an important behavioural response to overcome the infection. Fasting may assist in eliminating infection by saving energy that would otherwise be used in food gathering and preparation, reducing nutrients such as iron that are essential for the growth of pathogens, and enhancing the immune system by increasing macrophage activity.

Cough

Coughing is a spontaneous physiological defence mechanism against irritants that stimulate respiratory mucosa. It is a protective reflex that prevents aspiration of food and fluid into the airway but also assists in the expulsion of mucus and in forcing objects up from the lower airway to be expelled.

A productive cough should be not suppressed; instead, mucus-dissolving agents are recommended. Coughing with a cold or flu occurs later in the disease progression, related to the inflammation spreading to the lower airways, which triggers mucus production as a protective measure.

The mood changes associated with colds and flu are thought to be triggered by the effects of inflammation on the central nervous system.

Common-cold viruses do not cause any substantial damage to the lining of the airways but the influenza virus may cause cellular damage to this epithelium, resulting in mucus production. This is possibly why a severe cough is more associated with the flu, whereas a cold is more often considered a “head cold” with few cough symptoms. Secondary lung infections usually manifest as a persistent cough.

Respiratory herbs (and other cough medicines) fall into two major groups: expectorants and antitussives. The expectorants thin and dissolve mucus and help the body expel it. These do not necessarily stop the coughing as the cough reflex itself is needed to expel the mucus. Antitussives are herbs that soothe the dry, tickly, unproductive coughs that are commonly caused by an inflammatory/hyperactivity response in the upper airways. These groups are not mutually exclusive, however, and some cough medicines can both help expel mucus and reduce the episodes of uncontrolled coughing.

Mucus

Mucus is a slippery aqueous secretion produced by cells in various glands and covering the mucous membranes. It assists in the protection of the internal body surfaces. During infection or inflammation, greater volumes of mucus are produced.

The colour of the mucus is a useful indicator of the type of infection. The mucus the body produces from viral infections is generally clear or whitish, whereas the mucus from a secondary bacterial infection is coloured from yellow in the early stages to green when the condition increases in severity. It will always be more coloured in the mornings on waking as the mucus collects and thickens in the lungs overnight and the trapped bacteria can proliferate more easily in this semi-stagnant medium. Waking up coughing is the body’s attempt to expel irritants.

Prevention and treatment

Barrier protection

First and foremost, effective protection equates mostly to good hygiene. Make sure your hands are washed regularly after touching objects that other people have had contact with — hand rails, for example. It is said that handling money poses the greatest risk of contamination. Wearing gloves during the colder months can help with barrier protection.

You can’t beat a little natural soap and clean water. Traditional cleaning methods include soap and hot water or alcohol. Chlorine bleach or hydrogen peroxide can be used for heavy-duty surface cleaning. These act non-specifically and eliminate almost every type of microbe: fungi, bacteria and some viruses. Soap loosens and lifts dirt, oil and microbes from surfaces and is easily rinsed away with water. General cleaners such as alcohol demolish key cellular structures then evaporate. Even plain clean water reduces bacterial populations by sluicing them off.

Unfortunately, many commercial antibacterial products today leave surface residues, creating conditions that foster the development of resistant bacteria. After spraying and wiping antibacterial cleaners over a kitchen counter, active chemicals linger that kill most bacteria, but not all. The surviving bacteria then have the potential to mutate into strains resistant to the chemical, which can generate a cross resistance with medical antibiotics.

Residues of these antibacterial chemicals (eg triclosan) have been found in 60 per cent of the USA’s rivers, filtered out as sludge then used as fertiliser for food/vegetable growing. As well as developing cross-resistance, these chemicals can contribute to endocrine disruption in humans when consumed as residues on foods.

Wearing a face mask is often recommended for infection from droplet contagion (such as colds and flu) but, unless a person has a severely compromised immune system for other reasons, this is not so necessary. Having contact with the latest viral infection, and managing it effectively, upgrades our immune status for the next challenge. Face masks however can be effective in areas of high air pollution or when worn by people with severely compromised immunity.

Stress management

Mental and physical stress (neuroendocrine influences) can significantly affect immune function and stress has been shown to reduce the resistance of the organism to infectious disease. Regular techniques for stress management are therefore an important protective approach. Adrenal function needs to be supported while exercise and relaxation or meditative techniques, practised regularly, are critical for maintaining health and effective immunity.

Infection management

There are two ways to approach infection management once the person has contracted the infection: one is to stop the symptoms (and there is a good argument to reduce the inflammation caused by the organism); the other is to go with the body’s inherent defence mechanisms and enhance them so the immune system can deal with the infection itself. Deciding which approach to take will obviously be determined to a large extent by the virulence of the organism and the severity of the symptoms.

The symptoms we develop in response to infection can be the body’s best way of attempting to neutralise the infection. This is important with common conditions such as colds and flu because, in our attempts to stop the symptoms, we may be going against the wisdom of the body. Fever, for example, is an important clinical indicator and generally perceived as a healthy reaction by the body to combat infection and regain homoeostasis. Pathogenic organisms are more susceptible to heat than healthy cells.

While an acute inflammatory response needs to be managed effectively, taking anti-inflammatory medications such as paracetamol to reduce a fever can sometimes be counterproductive. There was a classic belief that the way to get rid of a fever was to go to bed and sweat it out. Diaphoretic herbs are sometimes used to increase and manage a fever in individuals who normally do not become feverish. These individuals can take longer to recover from an infection because, without the fever, it takes a few days longer to activate their immune systems sufficiently to manage the challenge.

While these techniques can be useful for adults, it is important to be very careful with children as with their smaller bodyweight they can become dangerously dehydrated with the fever. Cooling feverish children in a tepid bath and feeding them liquids (preferably pure water) frequently to prevent dehydration is a safer option while treating the infection with herbs and nutrients. Managing a fever correctly will reduce the duration of the infection, though sufferers will need to rest afterwards.

Rest

Adequate rest is a critical factor in the healing process. A common symptom of infection is fatigue. With infections, resting/sleeping for a few days not only works with the body wisdom for healing, it also helps prevent contagion of the wider community. “Soldiering on” is not necessarily a healthy option.

Medical prevention and treatment

Antiviral drugs

Antiviral drugs such as zanamivir or oseltamivir can limit the ability of the influenza viruses to infect respiratory cells and offer modest symptomatic relief. They are sometimes recommended for high-risk patients but there is no evidence that they decrease the risk of serious complications. They also have to be administered within 48 hours of onset to have any positive result — and then only reducing the duration of the illness by one day. Recent research has also indicated a potential issue with the development of viral resistance to these drugs.

The flu vaccine controversy

There is significant debate over whether to have the flu vaccine or not. If a person decides not to it is essential to support their health to maintain good immune function.

According to the United States’ Centers for Disease Control and Prevention (CDC), the effectiveness of the vaccine against influenza for the 2017/2018 flu season was 36 per cent while a 2014 meta-analysis concluded that 71 people needed to be vaccinated in order for a single case of influenza to be avoided (1 in 71 cases).

There is also a significant risk of debilitating side-effects. The efficacy of influenza vaccination is significantly impaired by ageing. It is estimated that vaccination can protect as few as 17 per cent of elderly individuals and the elderly are the ones most at risk from both the flu and the vaccine’s side-effects. This is also the group most likely to have compromised immune function. Moreover, there is evidence to suggest that when a person is vaccinated, even if they show no symptoms, they can still shed the virus and transmit influenza to other people.

In contrast, CDC figures have shown that, with vitamin D supplementation, the number of people protected was 1 in 33 — much better odds — and for those who were severely deficient in vitamin D the figure was 1 in 4. Even people with high levels of vitamin D reduced their risk of colds and flu by about 10 per cent. Vitamin D is a worthwhile supplement prophylactically, particularly as there are virtually no side-effects.

Nutrients to support immune function

Vitamin D

There is some very interesting research in the medical literature suggesting that taking vitamin D may be a far more effective strategy for influenza protection than the flu vaccine. The literature goes so far as to suggest that a vitamin D deficiency may be an underlying cause of influenza.

Many studies (over 15 years) have shown that people with the lowest vitamin D levels reported significantly greater frequency of cold and flu infections. The research indicates that this is applicable for all ages, from children to the elderly. Vitamin D improves lung function in other respiratory conditions such as asthma, pneumonia and bronchiectasis. Vitamin D has also shown significant anti-inflammatory effects, which play a role in reducing secondary bacterial infections.

Cod liver oil

Cod liver oil contains long-chain omega-3 fatty acids along with vitamins A and D. It was a traditional folk remedy for children, reducing both the risk of rickets and of respiratory infections, particularly in industrialised cities.

To confirm its value, a study was conducted on children aged six months to five years who were given cod liver oil and a children’s multivitamin supplementation over winter and in early spring. Those children taking the supplements reduced their visits to their local doctor significantly by between 36 and 58 per cent. Studies done in the elderly have shown similar results.

Vitamins A and D play important roles in both cell-mediated and humoral antibody response and support a Th2-mediated anti-inflammatory profile. A vitamin A deficiency impairs both innate immunity (mucosal epithelial regeneration) and the adaptive immune response to infection, resulting in an impaired ability to counteract the pathogens that cause these (respiratory) infections.

The omega-3 fatty acids are anti-inflammatory and moderate the host defence against bacterial and viral infections.

Vitamin C

A recent meta-analysis showed that vitamin C was an important supplement to prevent and treat upper-respiratory-tract infections in children, especially under the age of six years, an age when many say vitamin supplementation is unnecessary. In children (including infants) prone to colds and flu, vitamin C supplementation generated significant improvement. Supplements based on acerola berry or rosehip are preferable for children as they are more plant-based. Vitamin C is equally important for adults for cold and flu protection.

Zinc

Oral zinc has been shown to reduce the length and severity of a cold. Zinc supplements will also improve gut immunity and microbiota function, thereby improving systemic immunity. Zinc is anti-inflammatory, antioxidant and immunoregulatory and supplementation, particularly in the elderly, significantly lowers susceptibility to infection. Zinc has significant antiviral activity against the influenza (and other) viruses.

Selenium

Selenium is a very interesting nutrient. If deficient, benign strains of the influenza virus can actively mutate to the highly pathogenic forms, particularly influenza A virus (and a range of other viruses). Selenium status may also affect the function of the cells of both adaptive and innate immunity. Supplementation enhances the cellular immune response, making selenium a vital nutrient in protection against viral (and bacterial) infection. Selenomethionine (the organic form) is considered the most effective long term.

N-acetylcysteine

N-acetylcysteine or NAC is a potent antioxidant that has been used for many years to treat lung conditions due to its expectorant and mucolytic properties. One study involving 262 elderly subjects used 600mg oral NAC prophylaxis for six months. The incidence of influenza episodes in the treated group averaged 29 per cent compared to 51 per cent in the placebo group, and the severity of infection in the treated group was significantly less than placebo. Of the 262 subjects, 65 became infected with influenza (in both the treated and placebo groups) but only 25 per cent of the treated group had mild symptoms, compared with 79 per cent of the placebo group who also had more severe symptoms.

Quercetin with bromelain

When treating colds and flu (and other infections) there are two main aspects to consider: reducing the levels of the pathogenic organism and reducing the inflammatory response generated by the organism.

It is the inflammatory response that makes you feel so unwell and facilitates the spread of the virus or bacteria. Reducing the inflammatory response will therefore improve your symptoms but also weaken the pathogenic organism and reduce the damage it can cause. Many of our herbal medicines and nutritional supplements that are anti-infective also have strong anti-inflammatory properties. Quercetin (with bromelain for improved digestion) is particularly effective to boost the anti-inflammatory activity.

As well as being an exceptional anti-inflammatory and antioxidant, quercetin has powerful antiviral activity and inhibits a broad spectrum of viruses, including both the influenza A and B viruses, while lowering the risk for the development of secondary infections. It is possibly one of the most effective interventions to control viral infections. It has been shown to reduce viral internalisation and replication in vitro as well as reduce viral load, lung inflammation and hyper-responsiveness in airways.

Remember the microbiome

The gastrointestinal system has a critical role to play in immunity. An increasing number of studies show the intricate relationship of gut function and immune status in humans. The gut mucosa provides one of the first barrier mechanisms against environmental challenges, with the human gut microbiota responsible for 60–70 per cent of the effectiveness of the immune system.

Research has shown that probiotics are better than placebo at both reducing the frequency of episodes of acute upper-respiratory-tract infections and the severity and duration of these infections, thereby reducing the need for antibiotic prescriptions. Probiotics and prebiotics have been shown to increase resistance to colds and flu in both the elderly and in young children, those most at risk from severe infection. They are also effective in healthy adults to increase resistance, relieve symptoms and reduce the number of days off work.

Probiotics play a significant role in the prevention and treatment of acute upper-respiratory tract-infections by reducing inflammation, enhancing innate immunity and increasing natural killer cell activity, specifically against influenza viruses. They also enhance gut and respiratory immune responses and increase the influenza specific IgA and IgG antibodies. Probiotics have also been shown to reduce the side-effects of vaccination while enhancing immunity against the infective virus.

Lactoferrin

Lactoferrin is an important protein present in bodily secretions such as milk, saliva, tears and nasal exudations. It is a major component of the immune system and is part of the critical defence mechanisms on mucosal surfaces: the gut and the lungs. It has important antibacterial, antiviral, antiparasitic and antifungal activity. It is also considered anticancer and antiallergic.

There are many studies showing the antiviral activity of lactoferrin against viral pathogens that cause the common cold and influenza, inhibiting the viral attachment to target cells. Taken as a supplement, it also increases natural killer cell activity and reduces inflammation, leading to protection against viral infections. During infection and the subsequent inflammatory process, lactoferrin binds to iron and removes it as a substrate for bacterial growth.

Iron

Do NOT take iron supplements with any infectious disease. Iron is a trace mineral substrate for nearly all infectious micro-organisms. Humans have developed mechanisms to remove iron (into stores) from the mucosal surfaces, plasma and extracellular fluid to deprive the pathogenic organism of a basic “food” source. We become pale and listless/fatigued and develop the “anaemia of inflammation”. Depriving bacteria and viruses of iron is an important protective measure against infection.

Foods to fight infection

Manuka honey

Manuka honey is anti-inflammatory, antibacterial and antiviral. It is useful for both the prevention and treatment of colds and influenza as it effectively inhibits viral replication. It also helps improve mucosal linings of the gut and lungs and inhibits the biofilm development that protects pathogenic organisms from treatments.

Garlic (Allium sativum)

Garlic contains many compounds that have the potential to influence immunity. In a study, 120 subjects were recruited to research the influence of aged garlic extract on the immune system and its effect on the occurrence and severity of colds and flu. They consumed 2.56g of aged garlic for 90 days and the results showed an increase in natural killer cell activity with reduced cold and flu severity, a reduction in symptoms and a reduction in the number of school or work days missed, compared with subjects taking a placebo. Adding raw or cold-pressed garlic to your diet can be a good preventative strategy.

Black cumin seed (Nigella sativa)

Nigella or black cumin seed at a dose of 2g/day in food has shown broad-spectrum antiviral and antibacterial effects. The seed inhibits viral replication and increases the number of T cells, natural killer cells and macrophages. Traditionally, it has been used to reduce coughs, bronchitis, influenza, asthma, lung fibrosis and cancer.

Herbal remedies for protection and treatment

Andrographis (Andrographis paniculata)

There has been extensive research on the Ayurvedic plant Andrographis showing broad-spectrum antiviral activity by stimulating both the antibody response and the non-specific immune response in humans. It inhibited the highly pathogenic H5N1 avian influenza virus (amongst others), reducing viral replication, and had significant anti-inflammatory activity, thus preventing the virus from spreading.

In a randomised double-blind placebo-controlled study on 223 patients diagnosed with upper-respiratory-tract infections, all the symptoms of cough, expectoration, nasal discharge, headache, fever, sore throat, earache, malaise/fatigue and sleep disturbances improved. Compared to placebo, it was twice as effective.

In a meta-analysis on acute respiratory infections in adults and children (in a total of 7175 patients), Andrographis shortened the duration of coughs, sore throats and sick leave when compared with placebo.

Echinacea (Echinacea spp)

Echinacea has antiviral activity against the influenza viruses and is a traditional treatment against colds and flu. One study on 473 patients found it at least as effective as oseltamivir in early treatment of the flu, with reduced risk of complications and adverse events than the drug. Echinacea angustifolia, while expensive, has also been shown to improve the immune response to influenza vaccines.

Elderberry (Sambucus nigra)

Elderberry extracts are prescribed primarily as antiviral remedies for colds, influenza and herpes virus infections. The berries have major anti-inflammatory, immune-modulating and antioxidant properties. Elderberry neutralises the surface spikes on various viruses including influenza A and B so the viruses cannot pierce cell walls, enter the cell and replicate. Elderberry extracts have been shown to shorten the duration and lessen the severity of the common cold, particularly when combined with vitamin C and zinc. Several trials have shown clinical improvement by reducing the number of days of illness and reduction of symptoms.

Olive leaf extract (Oleo europa)

Olive leaf extract (preferably the fresh plant tincture) is a good preventative of colds and influenza. The phenolic compounds it contains have potent antiviral, antimicrobial, anti-inflammatory and antioxidant properties. The active ingredients are effective against a range of viruses including coxsackie virus, influenza and parainfluenza viruses as well as some bacteria. Research suggests these compounds not only reduce the infectivity but also inhibit the replication of viruses known to cause colds, influenza and respiratory-tract infections.

Licorice root (Glycyrrhiza glabra)

Licorice root has well-researched immunomodulatory and anti-inflammatory effects and is particularly effective against influenza A virus, reducing the viral uptake in human lung cells. Licorice root is also an excellent herb to support adrenal function and assists with stress management. However, do not take in high doses or for long periods of time if you have been diagnosed with high blood pressure.

Essential oils

Studies have shown the efficacy of essential oils in the management of colds and flu. Many of them have strong anti-infective/antiviral/antibacterial/antifungal activity. Used in inhalations (or in a vaporiser) they can be effective to reduce not only the infection but also to relieve symptoms. They are useful for children who do not like taking medicines. Essential oils pass easily though cell walls and membranes making inhalations a highly bioavailable method of treatment.

Using a vaporiser to inhale essential oils when diagnosed with influenza can be useful to both improve symptoms of lung inflammation and prevent secondary infections. Eucalyptus oil, thyme oil, oregano oil, lemon oil, rosemary oil amongst others, either alone or in combination have shown promise as broad-spectrum anti-infective and anti-inflammatory agents.

Oil of eucalyptus (Eucalyptus globulus) is anti-inflammatory, antibacterial and antiviral. It has shown a specific ability to protect against influenza, reduce the inflammatory process in the lungs and assist in the prevention of viral induced pneumonia (at least in mice).

Symptoms relief

Coughing

Thyme (Thymus vulgaris)

Thyme is an effective herb used to relieve the productive coughs of colds and flu. It is both expectorant (thins and expels mucus) and antitussive (reduces excessive coughing) as well as anti-infective and anti-inflammatory. It is traditionally used in the treatment of upper-respiratory-tract infections including colds and flu, bronchitis, whooping cough and asthma. Thyme is particularly useful for colds and flu where coughing up mucus is a symptom. Its effect on coughing can be useful for symptomatic relief of both productive coughs and dry coughs.

Mullein (Verbascum thapsus)

Mullein flowers are a common herb used in herbal formulas for colds and influenza. They are antiviral (against influenza viruses), antibacterial, anti-inflammatory, expectorant and demulcent (soothing for membranes). Traditionally, mullein was used for a variety of lung conditions as well as sore throats and headaches and to relieve symptoms associated with colds and influenza. In children, mullein flowers are commonly used to ease the pain of ear infections.

Head colds & sinusitis

Elder flower (Sambucus nigra)

Elder flowers have higher levels of anti-inflammatory compounds than the berries and are often used to reduce sinusitis, including that associated with viral infections.

Sore throats

Sage (Salvia officinalis)

Sage is a classic remedy for sore throats (acute pharyngitis). Combined with thyme and manuka honey as an infusion, it is anti-inflammatory (specifically for throat inflammation), antimicrobial and reduces night fevers and sweats. Excellent for the throat symptoms of colds and flu, sage has also been called the singer’s remedy for its healing properties on the throat.

Children’s doses

Children can safely take the same herbs and supplements as adults but the dose is less. As a general rule of thumb, an effective dose for infants is one-quarter the adult dose; a seven-year-old needs half the adult dose; a 14-year-old can take three-quarters the adult dose. This works well in general terms. To be more specific, the dose is calculated according to bodyweight. Interestingly, the elderly often require children’s doses as their metabolism changes with age, increasing their sensitivity to many treatments.

There is substantial research on various herbal combinations showing their effectiveness in reducing the viral load, the inflammation, ameliorating the symptoms, speeding the recovery rate and preventing secondary infections from developing. As colds and influenza are such ubiquitous conditions for humans worldwide, every culture has a variety of plant and nutritional medicines that have been shown to be effective.

In researching the options for both the prevention and treatment of respiratory infections, there were innumerable choices. In this article, a few of the common plants and nutrients prescribed by practitioners in Australia have been chosen from a cast of thousands.