A McGill University study published in Translational Research found that former smokers remain at higher risk for COPD and lung cancer due to persistent molecular changes in lung cells.
Researchers analyzed over 100,000 lung cells from 21 participants, discovering that while some damage heals after quitting, other cellular markers affecting immune response and blood vessel function remain.
A separate study in ERJ Open Research noted that young adult vapers and smokers both exhibit 15% lower exercise capacity compared to non-users, indicating vaping offers limited cardiovascular protection.