Study finds vascular health improves after quitting smoking or switching to e-cigarettes

Quitting smoking – and switching completely to e-cigarettes – can lead to measurable improvements in vascular health, according to a new systematic review published in the European Journal of Preventive Cardiology.

The study, conducted by researchers affiliated with the Centre of Excellence for the Acceleration of Harm Reduction (CoEHAR), analysed 23 prospective clinical studies involving a total of 11,702 participants to examine how vascular health changes after smokers stop using combustible tobacco or switch entirely to vaping.

Researchers focused on early cardiovascular markers such as arterial stiffness, wave reflection in arteries and endothelial function – the ability of blood vessels to relax and respond properly to changes in blood flow.

Across the studies analysed, smoking cessation was associated with measurable improvements in all three indicators. In some cases, improvements were detectable within just one month of quitting and were sustained for up to two years in longer follow-ups.

These early biological changes are considered significant because they occur well before clinical cardiovascular disease becomes evident.

The review also examined randomised controlled trials where smokers switched completely to e-cigarettes. In these studies, researchers observed improvements in endothelial function regardless of whether the devices contained nicotine.

The findings suggest that vascular damage associated with smoking may be primarily driven by exposure to toxic chemicals produced by combustion rather than nicotine itself.

However, the researchers noted that the overall certainty of evidence varied. Using the GRADE framework to assess the strength of the data, they found that many vascular outcomes were supported by low-certainty evidence due to methodological differences between studies.

Randomised controlled trials examining endothelial function showed moderate certainty of evidence, with consistent findings indicating improvements following smoking cessation or complete switching to e-cigarettes.

Cardiovascular disease remains the leading cause of death among smokers, and the researchers say identifying early improvements in vascular function helps demonstrate how quickly biological recovery can begin once exposure to smoke stops.

Prof Riccardo Polosa, founder of CoEHAR and co-author of the review, said the findings highlight how the recovery process begins at a much earlier stage than commonly recognised.

“We often focus on long-term outcomes like heart attacks or strokes, but the recovery process begins much earlier – at the level of the blood vessels,” he said.

“When combustion stops, vascular function starts to improve. These measurable changes show that removing exposure to smoke has immediate biological benefits.”