Effect of CA Marijuana Laws on Smoking, Marijuana, Alcohol, and Opioid

A better understanding of the downstream effects of California’s (CA) rapidly changing tobacco and marijuana policies is critical for public health. The liberalization of CA marijuana laws has the potential to contribute to the renormalization of smoking and expose both users and non-users of marijuana to second hand smoke. Studies are needed that evaluate whether the medical marijuana law (MML) and the Recreational Marijuana Law (RML), are having a substantial influence on CA tobacco and substance control efforts at the population level.

Assessment of cardiovascular effects of chronic marijuana smoking or exposure to secondhand smoke in humans

Matt Springer, PhD

We have shown in rats that acute exposure to mainstream smoke or secondhand smoke from marijuana impairs vascular endothelial function, and it has been reported by others that human tobacco smokers and people exposed frequently to secondhand smoke exhibit chronic endothelial dysfunction.  We therefore plan to recruit groups of people who are regular tobacco or marijuana smokers, or marijuana leaf vaporizer users, or people exposed frequently to marijuana secondhand smoke, to determine if they exhibit impaired endothelial function on multiple levels.

Cannabidiol in Pain and Symptom Management

Donald Abrams, MD

Dr. Abrams conducts clinical research of the use of cannabidiol for pain and symptom management, including for patients with sickle cell disease and chronic pain. He is also conducting an observational analysis of patients in San Francisco, San Diego and Chicago using cannabidiol-dominant products. Participants attending the integrative medicine center clinics in those cities as well as those at 3 dispensaries in each city to determine what they were using, how they were using it, for what and if it worked.

Cannabis and cardiovascular outcomes

Gregory Marcus, MD, MAS
  1.  Changes in heart rhythms associated with acute cannabis consumption using wearable ECG monitors and concomitant Bluetooth-enabled vaping devices
  2. Relationships between healthcare coding for cannabis abuse and cardiovascular outcomes (heart failure, myocardial infarction, atrial fibrillation, ventricular tachycardia, and sudden death) using OSPHD and HCUP databases

Cannabis and changes in healthcare utilization

Gregory Marcus, MD, MAS

Using Healthcare Cost and Utilization Project Data to assess changes in diagnostic codes, healthcare costs, and hospitalizations after legalization of recreational cannabis 

Cannabis and Health Evidence Review Project

Salomeh Keyhani, MD

We have four active evidence base review projects examining the health effects of marijuana including the effects of marijuana use on cardiovascular risk factors and outcomes, the hemodynamic effects of marijuana use, the pulmonary effects of marijuana use, and the association of marijuana use with cancer. Thus far we have determined that cannabis use is associated with tachycardia and that suggests smoking marijuana is associated with respiratory symptoms including cough and sputum production.

Cannabis and Health Outcomes

Salomeh Keyhani, MD, Amy Byers, PhD, MPH, Beth Cohen, MD, MA

Despite the increasing availability and use of cannabis, many questions remain about its potential risks and benefits. We are conducting several studies by leveraging “big data” to efficiently recruit several prospective cohorts to examine the impact of cannabis use on health. Using text processing methods, we have identified cannabis users and non-users and have recruited a national cohort of Veterans Affairs patients with existing heart disease that we will follow over time to determine how cannabis use effects medication adherence, blood pressure control and cardiovascular events.

Co-use of Cannabis and Tobacco

Pamela Ling, MD, MPH

We are pursuing both qualitative and qualitative behavioral studies of tobacco and cannabis co-use.

Community-based Prevention of Youth Cannabis Use in Marin County

Jeremiah Mock, MSc, PhD

Marin County communities have some of the highest rates of youth cannabis use in California. To address this problem, a collaborative prevention project was established between Marin Healthy Youth Partnerships, a community-based organization funded by a federal Drug-Free Communities grant, the Marin Prevention Network, and Marin County Health and Human Services.

Denormalizing Smoking in the Great Outdoors in California and throughout the Pacific Rim

Jeremiah Mock, MSc, PhD

Smoking and vaping in the outdoors are considered to be normal and acceptable in California and the Pacific Rim region. However, tobacco use in the outdoors results in harmful levels of secondhand smoke exposure, toxic tobacco, vaping and cannabis product waste, and fire hazards. This study identifies factors driving the cultural norm and pervasive notion that it is socially acceptable for smokers to smoke in the outdoors by analyzing past and current tobacco industry advertising, social media and political strategies in California, Thailand and Japan.

Environmental Contamination from Tobacco, Vaping and Cannabis Waste

Jeremiah Mock, MSc, PhD

This sentinel surveillance garbology study documents environmental contamination from e-cigarette product waste, combustible tobacco product waste, and cannabis product waste at public high schools with in Alameda, Contra Costa, Marin, and San Francisco counties. The study shows that e-cigarette waste and combustible tobacco product waste contaminate the Bay Area high schools, confirming use of these products by high school students. Cannabis product waste represents an emerging issue.

Environmental Effects of Marijuana Use

Suzaynn Schick, PhD

My lab studies the chemistry and toxicity of smoke, with a focus on tobacco and cannabis smoke. As part of the UCSF Human Exposure Laboratory, we perform controlled exposure studies that test the immediate health effects of cigarette smoke exposure in human beings.  We have shown that breathing secondhand cigarette smoke causes rapid increases in cardiovascular disease risk and in nasal congestion.  Our research on the chemistry and toxicity of cigarette smoke has helped define a new health risk from smoking: thirdhand cigarette smoke.

Evaluation of Potential Harmful Effects Marijuana Loose Leaf Vaporizers

Matt Springer, PhD

We have demonstrated that secondhand smoke from marijuana impairs vascular endothelial function in rats, an effect also caused by secondhand smoke from tobacco, but the marijuana effect appears to last longer.  This occurs even if the smoke is from marijuana lacking cannabinoids, indicating that the effect is caused by the smoke itself and not the cannabinoids. Therefore, we are exploring whether or not this effect can be avoided by use of loose leaf vaporizers, which heat marijuana to below combustion temperatures.

Exposure to Cannabinoids when Vaping Marijuana Products

Neal Benowitz, MD, Gideon St Helen, PhD
This project is studying exposure to THC and other cannabinoids and their effects after vaping cannabis oil. They will also be analyzing various cannabis products for concentrations of THC and other constituents.

Immune Effects of Cannabinoids and the Endocannabinoid System

Judith Hellman, MD

We are doing basic-translational research on the immune modulating effects of cannabis-derived and endogenous cannabinoids. We have found that phytocannabinoids, such as THC and several minor cannabinoids have anti-inflammatory effects in vitro on leukocytes and endothelial cells, and in vivo in models of acute systemic inflammation. We are currently studying the anti-inflammatory mechanisms of cannabis-derived cannabinoids and endocannabinoids, and their effects on inflammatory pain and on inflammatory critical illness. 

Impact of Cannabis and Synthetic Cannabinoid Use on Quality of Life in Patients with Central Nervous System Tumors

Nicholas Butowski, MD

We studied whether synthetic CBD (from Insys) could control brain tumors in a mouse model; results were unclear and Insys was not able to provide further support for more studies.  At present, we also are studying how our patient population uses CBD and THC and why and whether it may impact survival. This project is  entitled Impact of Cannabis and Synthetic Cannabinoid Use on Quality of Life in Patients with Central Nervous System Tumors (ICANCNS-QOL)

Impact of Medical Cannabis Laws on Youth

Laura Schmidt, PhD, MSW, MPH

Dr. Schmidt is working on how medical cannabis laws are impacting young people nationally, as well as California-specific work on shaping local policies, and the locations of outlets in low-income communities that are already densely populated with liquor outlets. Her work tracks alcohol-cannabis substitution and uses community-engaged approaches to bring evidence-to-policy around alcohol and cannabis at the local and state levels.

Impact of Recreational and Medical Marijuana Legalization on Tobacco Use, Marijuana Use, and Perceptions of Risk

Beth Cohen, MD, MA

This project follows a group of patients throughout the US that we surveyed in 2017 to examine how changes recreational legalization in California and other states have effected use of marijuana as well as perceptions of its risks. There is concern that recreational legalization of marijuana could lead to increases in use of tobacco, particularly with the availability of devices that can be used for both substances and the normalization of smoking and vaping.

Interaction of Cannabis and Tobacco

Neal Benowitz, MD

Our group is working on the nature of the interaction between cannabis and tobacco. We use biomarkers to determine the concordance of usage of the two products in adolescents, and are conducting a laboratory study on the pharmacokinetics and pharmacodynamics of vaped cannabis vs vaped tobacco vs vaped cannabis + tobacco.  I am also interested the cardiovascular effects of cannabis use in people with heart disease.

Investigation of rat models for the study of adverse cardiac effects of marijuana

Matt Springer, PhD

We have a pilot grant to determine the utility of rat models to study how marijuana use affects cardiac function, and the survival of cardiac tissue after a heart attack.

Linking variation in local substance use policies to health outcomes

Joanne Spetz, PhD

At the same time that regulations on tobacco and on opioid prescriptions have become more stringent, regulations on cannabis have become less stringent: as of 2019, 11 states had legalized recreational cannabis and an additional 22 states had legalized medical cannabis use. The effects of these diverging trends are not clear, in part due to dramatic differences in local policies. Our work assesses whether localities make consistent choices with respect to substance use policies, and which policies are associated with reduced substance use at the population level.

Linking variation in local substance use policies to health outcomes

Dorie Apollonio, PhD, MPP

At the same time that regulations on tobacco and on opioid prescriptions have become more stringent, regulations on cannabis have become less stringent: as of 2019, 11 states had legalized recreational cannabis and an additional 22 states had legalized medical cannabis use. The effects of these diverging trends are not clear, in part due to dramatic differences in local policies. Our work assesses whether localities make consistent choices with respect to substance use policies, and which policies are associated with reduced substance use at the population level.

Measuring Combined Tobacco, E-Cigarette, and Marijuana Use

Dorie Apollonio, PhD, MPP, Danielle Ramo-Larios, PhD

As companies promote new smoking devices that can easily be used for both tobacco and marijuana (e.g., electronic cigarettes [“e-cigarettes”], vaporizers), youth and young adults may be more prone to using both drugs.

Pharmacology of co-administration of cannabis and tobacco

Gideon St Helen, PhD

While co-administration of cannabis and tobacco is becoming increasingly common, the pharmacology of various modalities of co-administration is understudied.

Polytobacco Study

Pamela Ling, MD, MPH

This is a qualitative study of adults who use multiple tobacco products, followed over time, in order to better understand patterns of tobacco use, how they change, and what influences these changes. This study includes tobacco products, e-cigarettes and cannabis use.

Public Perceptions on the Health Effects of Cannabis

Salomeh Keyhani, MD

We have benchmarked opinions of a national sample of 16280 US adults on both the risks and benefits of marijuana use in 2017. Overall the public has a favorable impression on the health effects of marijuana and holds beliefs on marijuana that are not currently supported by the evidence. We are continuing this work by examining how the traditional media and social media covers the evidence associated with the potential benefits and harms of cannabis use.

Public Policy Issues Associated with Marijuana Legalization

Recreational marijuana use has been legalized in 8 states (as of 2017) and medical marijuana is widely legal. The political forces pushing for these changes have come from marijuana enthusiasts and businesses with very little involvement of organizations that prioritize public health. This research is examining this process as well as opportunities to inject a public health perspective into these policy debates.

Relationship Between Cannabis Use and Active and Passive Tobacco Smoking in Adolescents

Neal Benowitz, MD
This project is exploring the relationship between cannabis use and active and passive smoking in adolescents. This work includes analysis of the impact of blunt use (marijuana in a cigar wrap) on nicotine exposure.

State and local cannabis regulation and interactions with tobacco control policy

The emergence of the legalized cannabis market, combined with the spread of e-cigarettes (which can also be used to aerosolize cannabis), have changed the tobacco market.  In many places the historic pattern of youth beginning with tobacco and adding cannabis has been reversed, with more youth starting with cannabis and adding tobacco.  The pressure for public use of cannabis has the potential for undermining smokefree laws.  Finally, major tobacco corporations, which have been considering entering the cannabis market since the 1970s, are starting to move.  This research explores this new d

State Marijuana Policymaking

As more states and countries legalize recreational marijuana, the effects of increased marijuana use are impacting tobacco use.  Dr. Glantz studies the implementation of state marijuana policies, whether they are following best practices from tobacco and alcohol control, and how marijuana legalization impacts tobacco.  In collaboration with other UCSF facultym he also studies cardiovascular effects of marijuana smoke.

The action of minor cannabinoids on inflammatory and neuropathic pain

Chronic pain is a substantial public health problem, and the current treatment modalities are insufficient. Cannabis and cannabis extracts have been used for thousands of years for medicinal purposes including the treatment of pain. Using molecular, cellular and behavioral models of inflammatory and neuropathic pain, we hope to elucidate the peripheral sites of analgesic action of the minor cannabinoids – such as CBD. We propose that two key elements of minor cannabinoid action are due to modulation of the capsaicin receptor - TRPV1 and the cannabinoid receptor - CB1 in peripheral sensory neurons.

The Effects of Cannabis on Overdose and Mortality among Patients on Chronic Opioid Therapy

Salomeh Keyhani, MD

Several ecologic analyses have demonstrated that rates of opioid related mortality have dropped in states with recreational legalization of cannabis. However, it is unclear how cannabis effects the individual health of opioid users. We have designed a study using national VA data to examine how cannabis use among patients on chronic opioid therapy effects mortality. 

Tobacco and cannabis use among people living with HIV

Richard Wang, MD
The prevalence of tobacco use is higher among people living with HIV than in the general population, and it is estimated that, among those receiving anti-retroviral therapy, combustible cigarette smoking may pose a greater threat to health than HIV itself. This research is determining the impact of the rapidly changing landscape of inhalational exposures, ranging from heated tobacco products to vaporized cannabis extracts, on the health of people living with HIV.

Toxicant Exposure and Cardiovascular Effects: Cannabis vs Tobacco

Gideon St Helen, PhD

Proposition 64 legalized adult recreational use of cannabis in California, and there are concerns it will lead to an increase in prevalence and intensity of cannabis use in the state. Further, electronic vaporizers, which heat but do not combust cannabis materials, are being introduced in the market for use with cannabis. Vaporizers are perceived as safer alternatives to smoking and are gaining popularity.

Using Digital Tools to Understand Contexts and Consequences of High-THC Cannabis Use

Meredith Meacham, PhD, MPH
This mixed methods project seeks to understand emerging patterns of use and effects of different levels of THC and CBD content as well as various forms of use (smoking, vaping, dabbing, edibles), by examining digital information exchange about cannabis in online forums and through in-depth interviews and online surveys with people who use cannabis.

Validation of NIDA research marijuana for use in cardiovascular health studies

Matt Springer, PhD

Due to the continued restrictions on US cannabis researchers to work only on DEA-approved research marijuana that does not completely reflect most "real world" marijuana being used, we have arranged to have NIDA provide us with small batches of research marijuana that more accurately reflect real-world chemical composition and cannabinoid levels.  We plan to characterize the cannabinoid and terpene profiles of these batches and to compare their cardiovascular effects to those of standard research marijuana in rats.