Coffee can cause or worsen a cough in some individuals, a common experience that often leads people to question their morning routine. This phenomenon is typically not due to a respiratory infection but rather a consequence of physiological responses triggered by various compounds in the beverage. Understanding the specific mechanisms behind this effect can help determine how to best enjoy coffee without the irritating side effect.
Acid Reflux is the Main Culprit
The most frequent cause of a coffee-related cough is the relaxation of the Lower Esophageal Sphincter (LES) and the resulting acid reflux. The LES is a muscular valve between the esophagus and the stomach that normally prevents stomach contents from moving back upward. Coffee contains compounds, including caffeine, that can cause this sphincter to loosen.
When the LES relaxes, stomach acid can reflux into the esophagus, known as gastroesophageal reflux (GER). This acid irritation can trigger a protective reflex cough. The cough may be a symptom of laryngopharyngeal reflux (LPR), where the acid travels up to the throat and voice box. This constant irritation causes a chronic cough, often dry and persistent, appearing shortly after consumption.
Coffee also contains natural acids, such as chlorogenic and quinic acids, which contribute to its overall acidity and can directly irritate the esophageal lining. Furthermore, caffeine stimulates the stomach to produce more acid, increasing the volume of fluid available to reflux.
Other Irritants and Chemical Stimulants
Beyond the acid-reflux mechanism, other components and physical characteristics of coffee can irritate the respiratory system and trigger a cough. Caffeine is a central nervous system stimulant that can amplify the cough reflex.
Caffeine also has a diuretic property, increasing water loss that can lead to mild dehydration. A drier throat lining is more susceptible to irritation, which can worsen an existing cough.
The physical act of drinking coffee can be a factor, particularly when consumed too quickly or when excessively hot. Inhaling steam or tiny droplets of the liquid can lead to aspiration, triggering an immediate, forceful cough to clear the airway.
Some people may experience sensitivity to proteins in the coffee beans or to additives like flavorings, milk, or sweeteners. These sensitivities can manifest as throat irritation or increased mucus production, leading to a persistent need to clear the throat or cough.
Adjustments to Stop the Cough
Several simple adjustments can mitigate the cough associated with coffee consumption. Switching to a low-acid coffee variety can reduce the esophageal irritation that leads to reflux and a subsequent cough.
Coffees that have been dark roasted or processed via methods like cold brewing often have lower levels of irritating chlorogenic acid. Consuming coffee alongside food helps to buffer the stomach acid and can prevent the LES from relaxing severely.
It is also helpful to consciously sip coffee slowly and ensure the temperature is not scalding hot to avoid physical irritation or aspiration. Since caffeine can contribute to dehydration, drinking a glass of water alongside coffee can help keep the throat and airway linings moist. If the cough persists despite these changes, reducing the overall intake or switching to a lower-caffeine option may be necessary to limit the stimulant and reflux-inducing effects.