According to a new study, the legalization of cannabis is primarily associated with “small, sometimes significant, declines in longer-term adult tobacco use”.
The researchers found ‘consistent evidence’ that the passage of adult cannabis use laws in US states led to a slight increase in cannabis use among adults – between two and four points, according to the source of data – but tobacco has not followed this trend.
If the apparent substitution effect of cigarettes to cannabis, induced by legalization, were extended nationwide, it could result in healthcare cost savings worth more than $10 billion per year, concludes the study.
“We find little empirical support for the hypothesis that recreational cannabis laws increase net tobacco consumption, as measured across a wide range of combustible tobacco products as well as [les e-cigarettes] “, they write. “The preponderance of evidence instead points to small, sometimes significant, declines in adult tobacco use over the longer term.
“We conclude that recreational cannabis laws may have beneficial effects on tobacco-related health. »
Cannabis legalization and tobacco use
Authors from Bentley, San Diego State and Georgia State Universities published the findings in the Journal of Health Economics last month, calling the report “the first to comprehensively examine the impact of recreational cannabis legalization on smoking.” The study is based on federal data from the PATH survey (Population Assessment of Tobacco and Health) and the NSDUH survey (National Survey on Drug Use and Health).
While cannabis legalization enjoys overwhelming support from Americans, the researchers write that “public health experts have taken a more cautious approach, calling for more research to assess the benefits and costs of cannabis use. of marijuana for health, as well as to understand the potentially unintended consequences on other health behaviors”.
Some fear that the reform could lead to a “renormalization” of smoking, which would risk reversing nearly half a century of decline in cigarette consumption.
Smoking rates have dropped dramatically since the Surgeon General’s first report in 1964, with adult male smoking rates falling from 55% to 16% and female smoking rates from 35% to 12%. “Although the causes of these declines are the subject of much debate”, recognizes the study, “most public health experts seek to preserve the gains in health”.
The authors of the new study acknowledge that their analysis of the NSDUH data shows that legalization leads to “a (largely) statistically insignificant drop of 0.5 to 0.7 percentage points in tobacco consumption”, which includes cigarettes, pipe tobacco, smokeless tobacco and cigars. »
“However, this zero effect masks weak lagged effects of recreational cannabis laws on smoking. Three or more years after the passage of cannabis legalization, we find that tobacco use among adults decreases by approximately 1.4 to 2.7 points”.
With specific reference to cigarette smoking, they continue: “Again, although the overall treatment effect is relatively small […] three or more years after the passage of legalization, we see a statistically significant decline of 1.1 to 1.3 percentage points in adult cigarette consumption”.
To verify, the study also analyzed states that legalized cannabis earlier than others.
“The results support the hypothesis that smoking declined in several of the states that legalized cannabis earliest, including Colorado and Washington, which also saw the largest increases in cannabis use. cannabis consumption after the enactment of the law on the legalization of cannabis consumption. »
Legalization “is associated with a lagged reduction in the use of electronic nicotine delivery systems (ENDS), consistent with the hypothesis that ENDS and cannabis are substitutes.”
The researchers reported that the reduction in tobacco use in legal states is “primarily concentrated among men and for regulations that come with open recreational dispensaries,” results they say are “consistent with the hypothesis that recreational cannabis and tobacco may be substitutes for some adults”.
The article notes that the potential health care savings from substituting cannabis for cigarettes “could be substantial.”
“Our estimates suggest a reduction in smoking prevalence of 5.1 million people, which would translate into savings in tobacco-related health costs of approximately $10.2 billion per year,” the article concludes. .
Given that most states where cannabis is legal first passed medical cannabis laws, the study points out that it is possible that “the effects of recreational legalization are confounded with the long-term effects of medical legalization,” especially in light of the delays that often elapse between medical legalization and the start of legal sales in states.
Analyzes of the PATH data, meanwhile, reached similar conclusions. “Consistent with the NSDUH, we find no evidence that the passage of an adult cannabis use law significantly increased the use of combustible tobacco or e-cigarettes in the previous month” , write the authors.
“Although the estimated lagged effects are positive in most cases for the consumption of cigarettes, cigars and all combustible tobacco products, the effects are uniformly less than one percentage point – often less than 0.5 percentage points. percentage – and are statistically indistinguishable from zero at conventional levels. »
Additionally, the study found “no evidence that the adoption of legalization significantly increases tobacco product initiation among non-core users or decreases smoking cessation among core users.” “.
Legalization, however, was associated with a 1.2 to 1.3 percentage point increase in co-use of tobacco and cannabis, which the researchers attribute primarily to “cannabis initiation among the subpopulation of people who were already using tobacco before the policy change.
