Mucus is a naturally produced, slippery, aqueous secretion that covers and protects mucous membranes throughout the body. Primarily made of water, proteins, salts, and mucins (glycoproteins produced by goblet cells), it forms a thin layer lining the respiratory airways. This layer serves as a defense mechanism, trapping inhaled foreign particles like dust, allergens, bacteria, and viruses, preventing them from reaching the lungs. It also moistens inhaled air and keeps airway tissues from drying out. A common question is whether vaping can affect this natural process and lead to excess mucus production.
The Body’s Response to Vaping
Inhaling vape aerosols can irritate the delicate lining of the airways, triggering the body’s protective responses. This irritation can lead to an inflammatory response, prompting increased mucus secretion to trap and remove irritants.
Vaping can affect goblet cells, which produce mucus. Chronic irritation may cause these cells to increase in size or number (hyperplasia or hypertrophy), leading to an elevated capacity for mucus production. Studies show increased levels of mucin, a key mucus component, in the lungs of chronic vapers.
Vaping can impair the function of cilia, tiny, hair-like structures that line the airways. Cilia normally move mucus and trapped particles out of the respiratory tract through mucociliary clearance. Research indicates that vaping, particularly with nicotine, can decrease ciliary beat frequency and make mucus more viscous, hindering its movement. This impaired function, known as mucociliary dysfunction, means mucus removal is compromised. The accumulation of thickened mucus can make the lungs more susceptible to infection and injury.
Vaping Product Ingredients and Mucus
Specific components within e-liquids and vape aerosols contribute to mucus production. Propylene glycol (PG) and vegetable glycerin (VG) are common base ingredients. These substances are hygroscopic, meaning they attract and absorb water. When inhaled, they can dry out airway mucous membranes, prompting the body to produce more mucus in response. Studies indicate that PG and VG can increase mucin expression in airway epithelial cells.
Flavoring chemicals, widely used in e-liquids, also play a role. Certain flavorings, such as diacetyl and cinnamaldehyde, can act as irritants or allergens when inhaled. These irritants can lead to inflammation and increased mucus production. Research suggests these flavoring chemicals may harm cilia by altering gene expression, further hindering mucus clearance.
Nicotine, a common component in many e-liquids, can irritate the airways and affect respiratory defense mechanisms. Nicotine exposure can impair ciliary function, making mucus more viscous and difficult to clear. It has been shown to increase the expression of MUC5AC, a mucin glycoprotein, leading to increased mucus production.
Beyond e-liquid ingredients, the heating element in vaping devices can generate harmful byproducts, including heavy metals and ultrafine particles. When inhaled, these microscopic particles can cause irritation and inflammation in the respiratory tract. Chronic exposure to these irritants can exacerbate respiratory conditions and contribute to increased mucus production.