Study: Lung function fell in young e‑cigarette users after one year

A new longitudinal study published in the journal Tobacco Control found a measurable decline in lung function among young adults who used e‑cigarettes over the course of one year.

The researchers followed 22 e‑cigarette users aged 21–35, measuring lung function at the start of the study and again after one year. Tests were carried out between 9 and 11 a.m., about 12 hours after the participants' last use of tobacco products. The team monitored several spirometry indicators, including FEV1 (the forced expiratory volume in the first second), forced vital capacity (FVC) and the FEV1/FVC ratio.

Participants self‑reported how many times per day they used e‑cigarettes. "The results showed that lung function in young people is greatly reduced after only one year of using e‑cigarettes, but given the methodological limitations of the study, as well as the small number of participants, we must interpret the findings cautiously," the researchers warned.

Measured declines and frequency

The second round of testing found lower FEV1 values compared with baseline. The investigators estimated average declines in FEV1 that varied with reported daily use: a 100‑ml fall for those using e‑cigarettes five to nine times per day; a 190‑ml fall for those using them 10 to 29 times daily; and a 240‑ml decline for participants reporting 30 or more uses per day.

"However, the differences in FEV1 decline by frequency of e‑cigarette use were not statistically significant," the authors emphasised. The study notes that a reduced FEV1 is one of the principal markers linked with chronic obstructive pulmonary disease (COPD).

The report lists important limitations: the small sample size, pulmonary function measured only twice (baseline and after one year), and the absence of a non‑smoker control group—factors that prevent concluding causality. Katie East, Associate Professor of Public Health at Brighton and Sussex Medical School, warned that the study does not prove e‑cigarettes caused the changes and pointed out participants may have smoked up to five conventional cigarettes per month or used other tobacco products, which could influence results. Lion Shahab, Professor at University College London, also urged caution: "Lung function naturally declines with age, so the observed drop may not be a consequence of e‑cigarette use." Both experts said larger and longer studies are needed that include people who have only ever vaped and those who have never used any cigarettes, to determine whether e‑cigarettes independently affect lung function.

Photo: press material from the event