A study shows that heavy marijuana use may increase the risk of several types of head and neck cancer.
Researchers found a link between daily cannabis smoking and a nine-fold increase in several types of cancer in the mouth, throat and nose.
The study only looked at the heaviest users: those who were so addicted to marijuana that it was affecting their lives.
However, experts are concerned about the impact on recreational users.
The team wrote in the study that it “has significant public health implications as cannabis use increases among young adults and there is a trend toward legalization.”
A study published this week found that heavy marijuana users are up to nine times more likely to develop head and neck cancer
Federal research has shown that cannabis use is increasing, especially among Americans under the age of 30.
Scientists believe that cannabis smoke can irritate the upper respiratory tract and cause DNA damage that can lead to cancer formation.
The findings came just weeks after the Drug Enforcement Agency (DEA) downgraded marijuana’s legal classification.
It was moved from Schedule 1, which has the highest abuse potential, to Schedule 3, along with drugs such as ketamine and some anabolic steroids.
Schedule 3 drugs are still controlled substances that are subject to rules and regulations. People who traffic in these substances without permission can still be prosecuted by the federal government.
However, this reclassification will not automatically legalize marijuana for the entire U.S. Recreational marijuana is currently legal in 24 states, and 13 allow limited medical use.
As the substance has become legal in more states, its use and addiction have also become more widespread. For example, an NIH-funded study found that marijuana use among young adults reached an all-time high of one in 12 in 2021.
Rates rose the most in states like California, which legalized recreational cannabis in 2018.
A series of recent studies show that heavy marijuana use may be linked to health problems such as heart attacks, strokes and certain cancers, including head and neck cancer.
The number of cases of head and neck cancers, including tongue, tonsil and gum cancer, is also increasing. The National Cancer Institute (NCI) estimates that the number of cases has increased by 1 percent since 2012.
Experts believe this is due to the increase in the number of cases of the human papillomavirus (HPV) and an increase in alcohol consumption, which can stimulate the production of cancer cells.
Recreational marijuana is legal in 24 states, although other states have legalized it for medicinal purposes only
In the new study, published thursday In JAMA Otolaryngology – Head and Neck Surgery, researchers analyzed data from more than 230,000 adults, half of whom were diagnosed with cannabis dependence sometime between April 2004 and April 2024.
People who used a lot of marijuana were on average 42 years old, while the average age of people who did not use marijuana was 60 years old.
Heavy marijuana users were six to nine times more likely to develop various forms of head and neck cancer than people who did not use the substance.
Overall, cannabis users are three times more likely to develop head and neck cancer.
With a ninefold increase, the highest risk was seen in cancer of the larynx, or vocal cords. This form of the disease, which affects 13,000 Americans and kills about 3,500 a year, is most often caused by excessive tobacco and alcohol use.
The team believes that cannabis aggravates cells in the airways, making them more vulnerable to damage and less able to fight off cancer cells. However, they said more research is needed.
The study had several limitations, namely that it focused only on heavy marijuana users rather than more casual users. It is also unclear exactly how much cannabis users consumed and how often they started the habit.
