As cannabis users age, health risks appear to increase

As cannabis users age, health risks appear to increase

Benjamin Han, a geriatric and addiction medicine specialist at the University of California-San Diego, tells his students a cautionary tale about a 76-year-old patient who, like many older people, struggled with insomnia.

“She had trouble falling asleep and she would wake up in the middle of the night,” he said. “So her daughter brought her some sleep gummies” – cannabis edible sweets.

“She tried a rubber after dinner and waited half an hour,” Han said.

Feeling no effects, she took another gum, then another—a total of four over several hours.

Han advises patients trying cannabis to "start low; slow," starting with products that contain as little as 1 or 2.5 milligrams of tetrahydrocannabinol, or THC, the psychoactive ingredient that many cannabis products contain. However, each of the four gummies this patient took contained 10 milligrams.

The woman began to experience intense anxiety and heart palpitations. A young person might have brushed off such symptoms, but this patient had high blood pressure and atrial fibrillation, a heart rhythm disorder. Frightened, she went to an emergency room.

Lab tests and a heart reconstruction determined the woman was not having a heart attack and staff sent her home. Her only lingering symptom was embarrassment, Han said. But what if she became dizzy or lightheaded and was injured in a fall? He said he had injured patients in falls or while driving after using cannabis. What if the cannabis had interacted with the prescription medications she was taking?

“Being a geriatrician gives me a break,” Han said. “Our brains become more sensitive to psychoactive substances as we age.”

Thirty-nine states and the District of Columbia now allow the use of cannabis for medical reasons, and recreational use is also legal in 24 of those states and the District. With older adults increasing, “the benefits are still unclear,” Han said. “But we are seeing more evidence of possible harm.”

A wave of recent research points to reasons for older users, with cannabis emergency visits and hospitalizations rising and a Canadian study linking such acute care to subsequent dementia. Older people are more likely than younger people to try cannabis for therapeutic reasons: chronic pain, insomnia or mental health problems, although signs of its effectiveness in combating these conditions remain thin, experts said.

In an analysis of national survey data published June 2 in the medical journal Jama, Han and his colleagues reported that "current" cannabis use (defined as use in the previous month) among adults aged 65 or older had increased to 7% of respondents in 2023 and in 2005.

What is driving the increase? Experts cite the steady march of state legalization - use among older people is highest in these states - while surveys show the perceived risk of cannabis use has declined. A national survey found that a growing share of American adults – 44% in 2021 – incorrectly believed that smoking cannabis daily was safer than cigarettes. The authors of the study in Jama Network Open noted that “these views do not reflect the existing science on cannabis and tobacco smoke.”

The cannabis industry also markets its products to older adults. The Trulieve chain offers a discount to those it calls “wisdom” customers, 55 years old or older than “wisdom” customers. RISE Pharmacies led a year-long cannabis and empowerment program for two senior centers in Paterson, New Jersey, including dispensary field trips.

The industry has many satisfied older customers. Liz Logan, 67, a freelance writer in Bronxville, New York, had had sleep problems and anxiety for years, but the conditions became particularly debilitating two years ago when her husband died of Parkinson's disease. “I would often be up until 5 or 6 a.m.,” she said. “It’s driving you crazy.”

Logan searched for cannabis edibles online and found that gummies containing cannabidiol, known as CBD, alone didn't help, but those with 10 milligrams of THC did the trick with no noticeable side effects. “I don’t worry about sleep anymore,” she said. “I solved a lifelong problem.”

However, studies in the US and Canada, which legalized non-medical cannabis use for adults in 2018, show climbing rates of cannabis use among older people, both in outpatient settings and in hospitals.

In California, for example, cannabis-related emergency room visits by those 65 or older rose to 395 per 100,000 visits in 2019, up from about 21 in 2005. In Ontario, acute care (i.e. emergency visits or hospitalizations) resulting from 2008 to 2021 and more than 26 and 26 and 26 and 26 and 26 and 26 and 26 and 65 year old cannabis licenses.

“It doesn’t reflect everyone who uses cannabis,” warned Daniel Myran, an investigator at the Bruyère Health Research Institute in Ottawa and lead author of the Ontario study. “It catches people with more severe patterns.”

However, because other studies have shown increased cardiac risk in some cannabis users with heart disease or diabetes, "there are a number of warning signs," he said.

For example, a recent JAMA Network study revealed a disturbing older veteran who is currently using cannabis screen for cannabis use disorder.

As with other substance use disorders, such patients "can tolerate high amounts," said lead author Vira Pravosud, a cannabis researcher at the Northern California Institute for Research and Education. “They continue to use even if it interferes with their social or family or family responsibilities” and may experience withdrawal when they stop.

Among 4,500 older veterans (with an average age of 73) serving Department of Veterans Affairs health care facilities, researchers found that more than 10% had reported cannabis use in the past 30 days. Of these, 36% met the criteria for mild, moderate or severe cannabis use disorder as set out in the Diagnostic and Statistical Manual of Mental Disorders.

VA patients are different from the general population, Pravosud noted. They are much more likely to report substance abuse and have "higher rates of chronic illness and disability and mental illnesses such as PTSD" that could lead to self-medication, she said.

Current VA guidelines do not require clinicians to ask about cannabis use. Pravosud believes they should.

In addition, "there is increasing evidence of a potential effect on memory and cognition," Myran said, citing his team's study of Ontario patients with cannabis-related conditions who go to emergency rooms or are admitted to hospitals.

Compared to other ages and genders who sought care for other reasons, research shows that these patients (ages 45 to 105) had 1.5 times the risk of a dementia diagnosis within five years and 3.9 times the risk of the general population.

Even after adjusting for chronic health conditions and sociodemographic factors, those seeking acute care through cannabis use had a 23% higher risk of dementia than patients with non-cannabis-related conditions and a 72% higher risk than the general population.

None of these studies were randomized clinical trials, the researchers emphasized. They were observational and could not determine causality. Some cannabis research does not specify whether users smoke, vape, ingest, or use topical cannabis on painful joints. Other studies lack relevant demographic information.

“It is very frustrating that we are unable to provide more individualized guidance on safer consumption modes and levels of use that appear to be lower risk,” Myran said. “It just highlights that the rapid expansion of regular cannabis use in North America is beyond what we know.”

Given the health vulnerabilities of older people and the far greater effectiveness of current cannabis products compared to the weed of their youth, he and other researchers urge caution.

"If you're looking at cannabis as medicine, you should be open to the idea that there are groups that probably shouldn't use it and that there are potential adverse effects," he said. “Because that applies to all medications.”

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