The Asthma and Respiratory Foundation NZ (ARFNZ) is urging people to look after their lungs as Omicron hits communities.

A new University of Otago study has found that prolonged cannabis use led to over-inflated lungs and increased the resistance to airflow to a greater extent than tobacco.

ARFNZ Scientific Advisory Board Member and study co-author Professor Bob Hancox says: "Although the effects of cannabis were detrimental, the pattern of lung function changes was not the same as in tobacco use. This study also found that cannabis use may impair the ability of the lungs to extract oxygen from the breath. This is a known consequence of smoking tobacco, but has not been demonstrated with cannabis until now."

Another recent study from the Mayo Clinic in Rochester, Minnesota, looked at the effects of vaping on COVID-19 symptoms. Some 290 COVID-positive vapers aged 18 and older were compared with similar-aged people who had COVID-19 but didn't vape. The study found that those who vaped were more likely to report chest pain, chills, headaches, muscle aches, nausea, vomiting, diarrhoea and the loss of smell or taste. These patients also reported higher rates of laboured breathing, the new study findings showed.

ARFNZ Chief Executive Letitia Harding says: "Studies show that people who smoke and/or use e-cigarettes are more likely to experience a greater number of COVID-19 symptoms when they become infected."

ARFNZ is a strong advocate for Smokefree 2025, and urges people to quit smoking, as the detrimental effects of tobacco are well known.

Letitia adds: "These studies are a warning to everyone during a respiratory pandemic: don’t smoke tobacco, and if you are a smoker, now is the time to quit; don’t start vaping, and don’t use cannabis. That way, you’ll give your lungs the best chance against COVID-19."

For information on how to quit smoking go to for information on vaping and its effects on the lungs go to

The US vaping study was recently published online in the Journal of Primary Care & Community Health

The cannabis study was recently published online in the American Journal of Respiratory & Critical Care Medicine


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