Two studies were presented at the American Heart Association Scientific Sessions meeting (2023), showing that regular use of marijuana markedly increases risk for heart attacks and strokes in people with high blood pressure and/or high cholesterol (AHA Newsroom, Nov 6, 2023).
• Marijuana increases risk for heart failure by about one-third, compared to people who reported never using marijuana (Poster Abstract MDP250). Researchers followed 156,999 individuals for four years and found that two percent developed heart failure. Those who smoked marijuana daily had a 34 percent increased risk for heart failure, compared to those who never smoked marijuana.
• Marijuana increases risk for heart attacks and strokes in older people hospitalized with diabetes, and high blood pressure and/or high cholesterol (Poster Abstract MDP249). The 2019 National Inpatient Sample, the largest nationwide database of hospitalizations, found 28,535 cannabis users who did not also smoke tobacco but had major heart attack risk factors such as high blood pressure, Type 2 diabetes and/or high cholesterol. They had a 20 percent increased risk for suffering a major heart or stroke during hospitalization, compared to a 13.9 percent risk for those with the same risk factors but who did not use marijuana.
Why Marijuana Can Be Dangerous
“Cannabis Use Disorder” is inability to stop marijuana use, in spite of vomiting or inability to function normally in school or at work (Clin Trials, 2007;4:245-53). Globally, more than 23.8 million people have cannabis use disorder (Lancet, 2020;396:1204-22). Cannabis use ranks third worldwide among consumed substances of misuse, after alcohol and tobacco (Nat Rev Dis Primers, 2021;7:16) and can affect up to 50 percent of people who use cannabis daily (N Engl J Med, 2014;370:2219-27). Approximately three in 10 people who use marijuana have marijuana use disorder in which they have to take it regularly even though it is causing health and social problems in their lives (JAMA Psychiatry, 2015;72(12):1235–1242). For people who began using marijuana before age 18, the risk of developing marijuana use disorder is quite high (Drug Alcohol Depend, 2011;115(1–2):120–130). Marijuana contains up to 500 chemicals, including tetrahydrocannabinol (THC), a mind-altering compound. Marijuana can be smoked, vaped, or eaten in oils, teas and food.
Cannabis use is associated with increased risk for serious psychiatric disturbances (JAMA Psychiatry, 2019;76:426-34) including psychosis and schizophrenia (Lancet Psychiatry, 2015;2(3):233–238). It can damage many parts of your body (JAMA Network Open, 2019;2), including parts of the brain that regulate memory, learning, attention, decision-making, coordination, emotion, and reaction time.
Marijuana Can Help to Treat Some Conditions
Marijuana has been available by prescription for more than a decade in North America. One of the best studies on the risks and benefits of marijuana reviewed hundreds of studies and reported that marijuana can help to treat symptoms of multiple sclerosis, seizures, chronic pain, inflammatory bowel disease, and people with serious life-ending diseases (BMJ, Aug 30, 2023;382:e072348). It can:
• reduce asthma attack
• reduce eye pressure in glaucoma
• reduce depression
• help to control stomach cramps
• improve pain threshold
• improve quality of life for inflammatory bowel disease patients
• improve spasticity and pain for multiple sclerosis patients
• help to control anxiety and sleep disorders
However, smoking or inhaling anything raises blood levels of carbon monoxide and burnt-materials from smoke that can damage cells throughout the body.
Warnings
People at the highest risk for serious side effects from marijuana include:
• adolescents and people in early adulthood,
• people prone to, or with, mental health disorders,
• people who are likely to become addicted to drugs or alcohol
• pregnant women
Avoid driving a car or operating machinery after using marijuana.
