Importance
Following major policy changes in the United States, policy makers, clinicians, and the general public seek information about whether recreational cannabis use is associated with physical health problems later in life.
Objective
To test associations between cannabis use over twenty years and a variety of physical health indices at early midlife.
Design
A 38-year, prospective, longitudinal study of a representative birth cohort.
Setting
The Dunedin Multidisciplinary Health and Development Study of New Zealand.
Participants
The study included 1,037 male and female participants.
Exposure
We assessed frequency of cannabis use and also cannabis dependence at ages 18, 21, 26, 32, and 38 years.
Main Outcomes and Measures
We obtained laboratory measures of physical health (periodontal health, lung function, systemic inflammation, and metabolic health), as well as self-reported physical health, at ages 26 and 38.
Results
Cannabis use was associated with poorer periodontal health at age 38 and within-individual decline in periodontal health from age 26–38. For example, 55.61% of those with 15+ joint years had periodontal disease, compared with 13.53% of those who never used cannabis. Cannabis use was unrelated to other physical health problems, however. Unlike cannabis use, tobacco use was associated with worse lung function, systemic inflammation, and metabolic health at age 38, as well as within-individual decline in health from age 26 to 38.
Conclusions and Relevance
Cannabis use for up to 20 years is associated with periodontal disease but is not associated with other physical health problems in early midlife.