Coughs

Coughing is a simple response to irritation of the throat lining, which can have many possible causes. Depending on the cause, a cough can be ‘dry’ or ‘non-productive’, or can be associated with mucus or phlegm that is brought up by a ‘chest’ or ‘productive’ cough. For dry coughs the source of irritation needs to be identified and addressed, while in the case of a chest cough the source of the mucus discharge needs to be treated.

Dry cough

Dry coughs can be caused by bacterial or viral throat infections or by irritants such as household chemicals, smoke, solvent fumes (e.g., wet paint) or even drift from nearby crop spraying. They can also indicate low-level allergies to minute airbourne particles such as house dust (esecially when high levels of house mites are present), pollen, mould spores, pet skin sheddings, or aerosols from freshly cut grass or hay.

Persistent dry coughing may indicate mild asthma, or if it tends to occur only during early spring, may be a symptom of ‘hay fever’, even in the absence of more familiar symptoms such as light sensitivity, running eyes and nose or blocked nasal passages. In rare cases a chronic cough may be caused by from ‘acid reflux’.

Chest cough

A cough associated with phlegm is most likely to be caused by an upper or lower respiratory tract infection. This may be accompanied by shortness of breath, wheezing, fever or chills. If colds or ‘flue are ‘going around’ then this is obviously the most likely culprit, but anything out of the ordinary, or which lasts for more than a week or so should prompt a visit to your doctor.

Supplements that may help

The following supplements may be helpful, depending on the cause of a cough.

Bromelain

Bromelain extracts may help suppress a cough by reducing irritation, reducing nasal mucus associated with sinusitis, and relieving the swelling and inflammation associated with hay fever.

Quercetin

Often, bromelain is used together with quercetin, a flavonoid (plant pigment responsible for the colors found in fruits and vegetables). Quercetin has anti-histamine properties and, therefore, may be helpful if your cough is related to allergies.

Iron

One preliminary study suggested that iron supplementation may soothe and even prevent cough associated with a class of medications known as angiotensin-converting enzyme (ACE) inhibitors (such as enalapril, captopril, and lisinopril). ACE inhibitors are medications commonly used to treat high blood pressure and heart failure, but dry cough is a side effect that leads many people to discontinue their use. Despite this encouraging information, it is premature to conclude that taking iron with ACE inhibitors to reduce dry cough is safe or effective.

Zinc

Several important studies have revealed that zinc lozenges may reduce the intensity of the symptoms associated with a cold, particularly cough, and the length of time that a cold lingers. Similarly, nasal zinc gel seems to shorten the duration of a cold. However, zinc nasal spray does not appear to have the same benefit.

Herbs

The use of herbs is a time-honored approach to strengthening the body and treating disease. Herbs, however, contain active substances that can trigger side effects and interact with other herbs, supplements, or medications. For these reasons, herbs should be taken with care and only under the supervision of a practitioner knowledgeable in the field of herbal medicine. Also, your physician should know about all herbs you are taking or considering taking.

Echinacea (Echinacea angustifolia/E. pallida/E. purpurea)

Echinacea is used to reduce the symptoms and duration of the common cold and flu and to alleviate the symptoms associated with them, such as sore throat (pharyngitis), cough, and fever.

Ephedra (Ephedra sinica)

The decongestant pseudoephedrine is a synthetic version of ephedra that has been used traditionally to treat upper respiratory infections. The World Health Organization supports the use of ephedra as part of treatment for the common cold, hay fever, and sinusitis. Because of some serious risks associated with this herb (like stroke and irregular heart rhythm), use of ephedra should only take place under strict guidance and supervision by an herbal specialist and physician and only for short periods of time.

Eucalyptus (Eucalyptus globulus)

Eucalyptus oil acts as an expectorant (loosens phlegm in the respiratory passages). For this reason, it is commonly used to treat colds and coughs and is an ingredient of lozenges, cough syrups, and vapour rubs. Herbalists recommend the use of fresh leaves in teas and gargles to soothe sore throats and treat bronchitis and sinusitis. Eucalyptus oil helps loosen phlegm, so many herbal practitioners recommend inhaling eucalyptus vapours to help treat bronchitis, coughs, and the flu.

Garlic (Allium sativum)

People often use garlic to help reduce symptoms of colds, coughs, and bronchitis. In fact, studies suggest that garlic can help prevent colds and shorten the duration of symptoms (such as cough) once you have a cold.

Ginger (Zingiber officinale)

Ginger is valued around the world as an important cooking spice and is believed to help common cold and flu-like symptoms, which may include cough. Scientific proof of this traditional use is lacking, but it may work for certain individuals. Talk to your doctor about whether it is safe for you to try ginger.

Jamaica Dogwood (Piscidia erythrina/Piscidia piscipula)

Based on clinical experience, a professional herbalist may recommend Jamaica dogwood to relieve cough. It is important to note, however, that there has been little to no scientific research on Jamaica dogwood, so the safety and effectiveness of this herb is relatively unknown. Jamaica dogwood is a potent herb and should be used only under the guidance of a qualified healthcare professional.

Licorice (Glycyrrhiza glabra)

This herb has long been valued as a demulcent (soothing, coating agent) and continues to be used by professional herbalists today to relieve respiratory ailments from allergies, bronchitis, colds, and sore throats.

People who regularly consume large amounts of licorice (more than 20 g/day) may inadvertently raise blood levels of the hormone aldosterone, which can cause serious side effects including headache, high blood pressure, and heart problems.

People with high blood pressure, obesity, diabetes, or kidney, heart, or liver conditions should avoid licorice. This herb should also not be used by pregnant or breastfeeding women or by men with decreased libido or other sexual dysfunctions. Use of any licorice product is not recommended for longer than four to six weeks.

Linden (Tilia cordata/platypus )

Linden (lime tree) flowers may be recommended by an herbalist for colds, cough, or fever.

Lobelia (Lobelia inflata)

Lobelia, also called Indian tobacco, has a long history of use as an herbal remedy for respiratory ailments such as asthma, bronchitis, pneumonia, and cough. Today, lobelia is considered an effective expectorant, meaning that it helps clear mucus from the respiratory tract. Although few studies have thoroughly evaluated the safety and effectiveness of lobelia, a qualified healthcare practitioner may recommend lobelia (usually in combination with other herbs) for the treatment of cough, especially if due to either asthma or bronchitis.

It is important to note, however, that lobelia is a potentially toxic herb. Lobelia can be safely used in very small doses (particularly homeopathic doses), but moderate to large doses can cause serious adverse effects ranging from dry mouth and nausea to convulsions and even coma. Under the guidance of a qualified healthcare practitioner, however, lobelia, in combination with other herbs that affect the respiratory system, is considered relatively safe.

Marshmallow (Althaea officinalis)

A professional herbalist might consider using marshmallow for cough, based on long-standing, traditional use.

Peppermint (Mentha x piperita)

Menthol, the main active ingredient in peppermint thins mucus, and is, therefore, a good expectorant, meaning that it helps loosen and break up the phlegm of productive coughs. It is soothing and calming for sore throats (pharyngitis) and dry coughs as well.

Slippery elm (Ulmus fulva)

Slippery elm has been used as an herbal remedy in North America for centuries including by the Cherokee who used it for coughs and other conditions. In fact, slippery elm has received recognition from the U.S. Food and Drug Administration (FDA) as a safe and effective option for sore throat (pharyngitis) and respiratory symptoms, such as cough.

Stinging nettle (Urtica dioica/Urtica urens)

Stinging nettle may act as an expectorant (meaning that it can loosen and break up a cough). Nettle may also be effective for treating certain individuals with allergic rhinitis (hay fever). This traditional use has had a lot of historical value for individuals. Early studies of people suggest that this historic use is likely scientifically valid. However, while the studies thus far have been favorable, they have not been overwhelmingly so. More research would be helpful. In the meantime, talk to your doctor about whether it is safe for you to try nettle as a possible alternative treatment during allergy season if you are prone to hay fever, which often manifests as cough.