Sweet Relief for Cough

If like millions of Americans you reach for drops or syrup at the first sign of a cough this post is for you. Until now, most cough experts were unsure if, and how, these popular remedies work.

However, new findings from the Monell Center –  a non-profit institute dedicated to research on the senses of taste and smell – may provide the answer.

It turns out that  both sucrose and menthol, ingredients used as flavorings in many of these preparations, can themselves, reduce coughing.

Cough is a vital protective reflex that clears the respiratory tract of threats from mechanical stimuli like food and chemical stimuli such as airborne toxins and pollutants. As such, cough is necessary to protect the lungs, and keep our airways clear.

Individuals with a weak cough reflex are at increased risk of pneumonia and of choking. Conversely, many acute and chronic conditions involve frequent coughing, leading to 30 million health care visits annually, with billions spent on over-the-counter medications and billions more lost due to reduced productivity,” said lead author, Paul Wise, PhD, a sensory psychologist at Monell.

However, many aspects of coughing remain poorly understood, including how chemicals act to trigger and modulate cough.

The study, published in Pulmonary Pharmacology and Therapeutics, involved 12 healthy young adults. Each participant  inhaled nebulized capsaicin, the burning ingredient in chili peppers which induces a cough. After each inhalation, the amount of capsaicin was doubled. This procedure continued until the subject coughed three times within 10 seconds. The capsaicin concentration that induced the three coughs was labeled as the individual’s cough threshold.

In some sessions, the subjects held either a very sweet sucrose or plain water in their mouths for three seconds, before spitting the liquid into a sink, and inhaling from the nebulizer.

In other sessions, subjects inhaled three breaths of either menthol-saturated air or clean air before each capsaicin inhalation. The menthol concentration was selected to approximate the cooling intensity of a menthol cigarette.

Both sucrose and menthol increased the amount of capsaicin needed to elicit a cough relative to plain water or clean air, respectively. Sucrose increased cough threshold by about 45%, while menthol increased it by approximately 25%.

This is the first study to empirically show that sweet taste reduces cough. This also is the first study to show that menthol alone can reduce coughing in response to a cough-eliciting agent,” said co author Paul Breslin, PhD.

The findings support the hypothesis that adding menthol to cigarettes may make it easier to begin smoking by suppressing the cough reflex, thus making the first cigarettes less distressing.

The researchers are planning further studies to explore the chemical elicitation of cough, along with the receptors and genes involved in this system.

In the meantime, it appears that sweet breath mints might be every bit as effective as cough drops… and possibly a whole lot cheaper.