The Truth About Medical Marijuana

Upsides, downsides

Twenty-eight years after California became the first state in America to legalize medical marijuana, and five years after AARP’s 2019 comprehensive look at cannabis, there are still plenty of unknowns about the health benefits and risks of all forms of medical cannabis. That category includes marijuana and its compound tetrahydrocannabinol (THC) that gets users high, as well as cannabidiol (CBD), a product derived from hemp plants that contain very low quantities of THC. Also in the category are emerging cannabinoids including CBN and Delta-8 THC, which are synthesized from hemp.

The best evidence indicates that cannabis helps with chronic pain and some sleep and anxiety problems, says Samoon Ahmad, M.D., a clinical professor of psychiatry at NYU Grossman School of Medicine and coauthor of a medical marijuana handbook. “Cannabinoids appear to be most effective in treating neuropathic [nerve] and other types of chronic pain, which are more prevalent in older patients,” Ahmad says. “Patients often say that it’s like the volume has been turned down so that the pain is less perceptible.”

However, cannabis doesn’t help much with short-term pain, such as a headache, sprained ankle or recovery after surgery, he adds. And it is not a proven treatment for glaucoma or high blood pressure. In 2024, regular use was linked with a 25 percent higher risk for heart attacks and a 42 percent higher risk for stroke.

Gummy quirks

More Americans, young and old, prefer gummies and other edibles, both for their ease of use and averred health reasons. “Infused edibles, including gummies, are generally more discreet to consume,” notes Brian Sterling, head of the Canadian research company SCS Consulting. “And consumers generally are more leery of smoking any product, cannabis included. This hesitance does increase as folks grow older.”

Sterling expects edibles to continue to surge past smoked and even vaped cannabis as users shy away from inhaled products that could affect the lungs. But edibles pose a unique risk: It’s easy to overdo them. “They look like candy,” says marijuana researcher Kevin F. Boehnke at the University of Michigan. “If somebody is like, ‘Oh, this tastes good, I’m going to eat a couple,’ you could have too much. It can take two to three hours to feel the full effects.”

That can have unintended consequences. A 2023 study found that emergency room visits for cannabis-related problems increased 1,808 percent among people 65 and older from 2005 to 2019 in California. Similarly, a 2024 study published in JAMA Internal Medicine found a jump in cannabis-related ER visits among older adults in Canada after cannabis was legalized.

As has long been the case, research on cannabis, though ramping up, is thin. In one study of cannabis-related ER visits, researchers found that 10.7 percent involved edibles from 2014 to 2016 — even though edibles accounted for less than 1 percent of cannabis sales at that time. Sudden, short-term mental health problems such as severe anxiety and cardiovascular symptoms were more common among those who used edibles than smokers and vapers.

All that explains why at the Leisure World Cannabis 101 Club, Carminetta Verner is very cautious about spreading the gummy gospel. She recommends that new users keep a detailed journal of what they take, as well as the results, to see whether a gummy, or anything else, helps or has side effects. 

“Each person’s metabolism is different, and you have to learn how your body reacts,” she says. “The cannabis mantra is ‘start low and go slow.’ ”