The potential health risks of daily marijuana use have become a subject of increasing concern, especially with its expanding legalisation and social acceptance. A recent study published in JAMA Otolaryngology–Head & Neck Surgery has shed light on a troubling association between regular cannabis use and the risk of developing deadly head and neck cancers. The study, which utilised a vast dataset of millions of medical records, underscores the need for heightened awareness and further research into the long-term effects of cannabis consumption.

Study Findings

The research indicates that individuals with cannabis use disorder—defined by symptoms such as cravings, tolerance, and withdrawal—are significantly more likely to develop various forms of head and neck cancers than non-users. Specifically, the study found:

• Oral Cancer: Individuals with cannabis use disorder are approximately 2.5 times more likely to develop cancers of the oral cavity.
• Oropharyngeal Cancer: The risk of developing cancer in the oropharynx, which includes the soft palate, tonsils, and throat, is nearly five times greater among daily cannabis users.
• Laryngeal Cancer: The risk increases dramatically, with users being over eight times more likely to develop cancer of the larynx.

These findings raise serious concerns about the safety of daily cannabis use, particularly as it pertains to smoked cannabis, which is the most common method of consumption.

The Role of Cannabinoids

Cannabis smoke contains over 540 chemicals, including more than 100 cannabinoids—compounds that interact with cannabinoid receptors in the human body. Tetrahydrocannabinol (THC), the psychoactive component of cannabis, and cannabidiol (CBD), known for its medicinal properties, are the most studied cannabinoids. However, research suggests that certain cannabinoids might accelerate tumour growth, particularly in cancers associated with the human papillomavirus (HPV).

Experts highlight that the manner in which marijuana is smoked—often unfiltered, deeply inhaled, and held in the lungs—may exacerbate its carcinogenic potential, similar to the well-documented risks of tobacco smoke.

Prevalence and Expert Opinions

Head and neck cancers account for about 4% of all cancers in the United States, with over 71,000 new cases and more than 16,000 deaths expected in 2024. While tobacco and alcohol use remain the primary risk factors, the potential link between cannabis use and these cancers cannot be ignored. Experts like Dr. Niels Kokot, a senior author of the study, emphasise the need for public awareness about these risks and advocate for ongoing research to fully understand the implications of long-term cannabis use.

Dr. Joseph Califano of UC San Diego’s Hanna and Mark Gleiberman Head and Neck Cancer Center notes the power of the study’s large dataset in uncovering these associations, despite the lack of differentiation between methods of cannabis consumption.

The Need for Further Research

Given the rising trend of marijuana use, particularly among younger populations, there is a pressing need to explore the long-term health impacts of cannabis. Researchers call for more comprehensive studies to confirm these associations and provide clearer guidance on cannabis consumption’s safety. As Dr. Kokot warns, the normalisation of cannabis use could lead to an increase in head and neck cancer cases, making it imperative to address this public health issue now.

Source: CNN