Does the consumption and co-consumption of tobacco and cannabis influence lung function: a longitudinal study
A study that looked at tobacco smokers and cannabis smokers when they were 21 and again at 29 found that tobacco smokers clearly had impaired lung function, but cannabis smokers had none.
Smoking cannabis, unlike smoking, does not harm lung function, at least not in young adults, study finds new study conducted at the School of Public Medicine at the University of Queensland in Australia, and published last month in the Journal of Respiratory Medicine.
As part of the study, which was conducted over 9 years and examined the relationship between lung function and smoking cigarettes, smoking cannabis and smoking both together, researchers examined the lung functions of 1 young people at using a standard lung function test, which is done by blowing air into a medical device called a spirometer.
Study subjects underwent lung function tests twice – once at age 21 and a second time at age 29, so they could compare test results and see the evolution of their lung functions over the years.
In addition to lung function tests, subjects also completed questionnaires regarding the frequency of their tobacco and cannabis use and amounts consumed, so researchers can compare damage to lung function in smokers versus cannabis users, and versus those who use both together.
The subjects were also asked about other factors that may affect their lung functions so that the researchers could rule out their influence on the results, such as the frequency of physical activity they engage in and history of various diseases, as well as their height and weight. measure.
The results showed that 34,8% of study subjects smoked cigarettes by age 21, 23,1% smoked cigarettes by age 30, and 17,8% of subjects smoked cigarettes both at the age of 21 and at the age of 30. . In contrast, 21,7% of study subjects smoked cannabis at age 21, 16,9% smoked cannabis at age 30 and 9,7% of subjects smoked both at age 21 and 30.
The results of the study show that while the lung functions of cigarette smokers were significantly damaged during the 9 years between the first and second tests, no similar decrease in the lung functions of cannabis smokers was observed. been observed.
Of the subjects who reported smoking both cannabis and tobacco, the degree of lung function impairment was the same as that of tobacco smokers, but not more severe, meaning that the addition of cannabis did not worsen the damage caused by tobacco.
“Smoking, with or without cannabis use, is associated with decreased lung air capacity,” the researchers wrote. “There is no relationship between cannabis use and measures of lung function, and simultaneous use of tobacco and cannabis does not increase damage to lung function beyond that caused by tobacco alone. »
“The study results show that smoking cigarettes regularly causes a decrease in the air capacity of the lungs even in healthy young people,” they concluded. “We found no link between cannabis use and lung function, even after years of prolonged use
- • Smoking and cannabis use and co-use are risk factors for impaired lung function.
- • By age 30, those who have smoked cigarettes since adolescence already show evidence of impaired lung function.
- • At age 30, those who have used cannabis since adolescence do not appear to show signs of impaired lung function.
- • Concomitant tobacco and cannabis use does not appear to predict lung function beyond the effects of smoking alone.