States that legalize cannabis see tobacco consumption decline, study finds

According to a new study, the legalization of cannabis is primarily associated with «slight, and sometimes significant, declines in tobacco use among adults over the longer term.».

Researchers have found «consistent evidence» that the adoption of laws on’Adult cannabis use in U.S. states led to a slight increase in cannabis use among adults—between two and four percentage points, depending on the data source—but tobacco use did not follow this trend.

If the apparent shift from cigarettes to cannabis—driven by legalization—were to extend nationwide, it could result in savings in healthcare costs of more than $10 billion per year, the study concludes.

«We find little empirical support for the hypothesis that laws on cannabis »Recreational use increases net tobacco consumption, as measured across a wide range of combustible tobacco products as well as [e-cigarettes],« they write. “The preponderance of evidence instead points to slight, and in some cases significant, declines in tobacco use among adults over the longer term.”.

«We conclude that laws on recreational cannabis may have beneficial effects on tobacco-related health.»

Cannabis legalization and tobacco consumption

Researchers from Bentley University, San Diego State University, and Georgia State University published these findings in the Journal of Health Economics last month, describing the report as «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 the legalization of cannabis benefits massive support from the Americans, the researchers write that «public health experts have adopted a more cautious approach, calling for further research to assess the health benefits and costs of marijuana use, 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 could reverse nearly half a century of declining cigarette consumption.

Smoking rates have fallen dramatically since the first Surgeon General’s Report in 1964, with smoking rates among adult men falling from 55 % to 16 % and smoking rates among women from 35 % to 12 %. «Although the causes of these declines are the subject of much debate,» the study acknowledges, «most public health experts are working to preserve these health gains.».

The authors of the new study acknowledge that their analysis of NSDUH data shows that legalization leads to «a (largely) statistically insignificant decrease of 0.5 to 0.7 percentage points in tobacco use,» which includes cigarettes, pipe tobacco, smokeless tobacco, and cigars.»

«However, this null effect masks small, delayed effects of recreational cannabis laws on tobacco use. Three years or more after the legalization of cannabis, we find that tobacco use among adults decreases by approximately 1.4 to 2.7 percentage points.».

With regard specifically to cigarette consumption, they continue: «Here again, although the overall effect of the policy is relatively small […] three years or more after legalization, we observe a statistically significant decrease of 1.1 to 1.3 percentage points in cigarette consumption among adults.».

To check, the study also analyzed the states that legalized cannabis earlier than others.

«The results confirm the hypothesis that smoking rates have declined in several of the states that legalized cannabis earliest, particularly in Colorado and Washington State, which are also the states that saw the sharpest increase in cannabis use following the enactment of the law legalizing recreational cannabis use.»

Legalization «is associated with a delayed reduction in the use of electronic nicotine delivery systems (ENDS), which is consistent with the hypothesis that ENDS and cannabis are substitutes.».

The researchers noted that the reduction in tobacco use in states where cannabis is legal is «primarily concentrated among men and in states where regulations are accompanied by the opening of recreational dispensaries,» findings that, according to them, are «consistent with the hypothesis that recreational cannabis and tobacco may be substitutes for some adults.».

The article notes that the potential savings in healthcare costs resulting from replacing cigarettes with cannabis «could be substantial.».

«Our estimates suggest a reduction in smoking prevalence of 5.1 million people, which would result in savings of approximately $10.2 billion per year in tobacco-related healthcare costs,» the article concludes.

Given that most states where cannabis is legal first enacted medical cannabis laws, the study points out that it is possible that «the effects of recreational legalization may be confused with the long-term effects of medical legalization,» particularly given the time lags that often occur between the legalization of medical cannabis and the start of legal sales in the states.

Analyses of PATH data, meanwhile, reached similar conclusions. «Consistent with the NSDUH, we find no evidence that the passage of an adult-use cannabis law significantly increased the use of combustible tobacco or e-cigarettes in the previous month,» the authors write.

«Although the estimated lagged effects are positive in most cases for the consumption of cigarettes, cigars, and all combustible tobacco products, the effects are consistently less than one percentage point—often less than 0.5 percentage points—and are not statistically different from zero at conventional significance levels.»

Furthermore, the study found «no evidence that legalization significantly increases initiation into tobacco use among current non-users or reduces smoking cessation among current users.».

Legalization, however, was associated with a 1.2- to 1.3-percentage-point increase in the concurrent use of tobacco and cannabis, which the researchers attribute primarily to «initiation into cannabis use among the subpopulation of people who were already using tobacco before the policy change .».