A large UC San Diego study finds that individuals with cannabis use disorder are about three times more likely to develop oral cancer than those without the disorder. Published in mid-2025, the research arrives as Thailand expands cannabis access, raising public health questions for a country navigating rapid legalization and shifting social norms.
Oral cancer affects the mouth, gums, and throat and remains a global health challenge, including in Thailand, where oral cavity cancers contribute a notable share of cancer deaths. Traditional risk factors such as tobacco and alcohol use have long driven these outcomes. The UC San Diego study analyzed hundreds of thousands of electronic health records and identified a robust link between chronic, problematic cannabis use and higher oral cancer risk, after careful adjustment for tobacco and alcohol consumption.
In Thailand, the findings arrive at a sensitive moment. A senior specialist in the Ministry of Public Health’s Cancer Division describes the study as an early warning as cannabis regulation becomes more permissive. Dentists and oncologists in Bangkok and other cities report rising concerns about oral health among cannabis users, underscoring the need for solid evidence to guide public health responses.
Thai culture has a deep history with herbal medicine, and medicinal cannabis remains a topic of public interest alongside recreational use. Since 2022, legalization momentum has paralleled growing youth experimentation. A 2024 survey by the Department of Medical Services shows noticeable cannabis experimentation among Bangkok students, alongside a rise in cannabis-related clinic visits nationwide.
International perspectives reinforce the study’s relevance. A 2023 systematic review in the journal Oral Oncology suggested links between long-term cannabis use and oral cancer, proposing mechanisms such as chronic inflammation, exposure to carcinogenic smoke, and immune effects. The UC San Diego study strengthens the case with its large sample size and rigorous controls.
Policy implications in Thailand are significant. As cannabis products and vaping devices become more accessible in major cities, questions arise about regulation, youth access, and health warnings. Health authorities are examining whether current labeling adequately conveys cancer risks. Professional bodies, including the Dental Council of Thailand, advocate for clear oral cancer risk information on cannabis product warnings.
Culturally, cannabis is sometimes viewed as a lower-risk option compared with alcohol or tobacco. Yet the new findings emphasize that frequent, heavy use—especially smoking or vaping—carries real health consequences. A public health educator from a Thai university stresses the need for science-aligned education to prevent past mistakes seen with tobacco.
Moving forward, Thai researchers and public health agencies are likely to conduct locally focused studies on cannabis use and oral cancer. NGOs working with youth health and cancer prevention are planning awareness campaigns for schools and universities to inform students and families.
Practical steps for readers:
- If you use cannabis, particularly by smoking or vaping, maintain regular dental checkups and report any persistent mouth sores or unusual changes to a dental professional promptly.
- Families and educators should share accurate information about potential risks to help youths make informed choices.
- Policymakers and cannabis traders should ensure health risk information is clear, accessible, and visible at points of sale or usage.
The UC San Diego study adds an important perspective for Thailand’s public health strategy. Balancing opportunities from cannabis policy with strong health protections will require robust education, prevention, and early detection efforts informed by global and local research.
In summary, cannabis use is not risk-free. As Thailand continues to shape its cannabis landscape, integrating scientific evidence into public health planning will be crucial for protecting oral health and overall well-being.