Seventy-two-year-old Nancy Young shakes almost incessantly, a cruel symptom of the Parkinson’s disease she’s borne for decades. The Otego, New York, resident, who lives much of the time in Sutton with her daughter, Michelle Edelstein, Sutton Senior Center director, has taken prescribed opioids OxyContin and Percocet for nearly 30 years. She said it “just barely covers the pain” of her condition.

Around Christmastime last year, Ms. Young decided, on the recommendation of people she met in the supermarket and eventually, her doctor, to try marijuana to ease her symptoms.

She didn’t roll a joint or buy a bong. Instead, she went with her daughter to a Canna Care Docs clinic in Worcester to receive a medical marijuana certification, registered with the state and purchased some edible marijuana products at the Curaleaf dispensary in Oxford.

“I was looking for a way to walk and keep my feet under me, and to stop this infernal shaking,” Ms. Young said in an interview at the Sutton Senior Center.

It took a bit of experimenting to find the right way to consume cannabis. First she tried a cannabis-infused chocolate bar.

“I’m a chocaholic and I took the whole thing,” she said. “My head was going like nobody’s business.”

Ms. Young learned the hard way about “start low, go slow” with marijuana edibles. And she found a different medium she much prefers: a tincture she drops under her tongue when the tremors get bad, especially in the evening.

“It makes me relax, which in turn slows the shaking down and I can grab some sleep,” she said.

“I’m grateful to see her not take those opioids so much,” Ms. Edelstein said. Noting her mother’s reduced pain and relief from other pharmaceutical side effects, she said, “I have to say, I’m kind of an advocate for it.”

Ms. Young is one of the fastest-growing group of marijuana consumers: older adults.

A recently released study out of New York University, supported by the National Institute on Drug Abuse, looked at data from the National Survey on Drug Use and Health, an annual survey of 70,000 Americans of all ages.

Researchers found that in the 2015-2016 survey, 9% of adults ages 50 to 64, and 2.9% of those 65 or older, reported using marijuana in the past year.

That prevalence is a 27% increase for 50- to 64-year-olds, and a 107% increase - essentially doubling - for those 65 or older since the 2012-2013 survey. Compared with the 2006-2007 survey, the increases are 100% for 50- to 64-year-olds and 625% for 65 or older.

A Massachusetts survey by the state Department of Public Health, conducted in late 2017, before recreational marijuana stores were open, found that 18.7% of people in their 50s, or nearly one in five residents in that age group; 14.1% of people in their 60s; and 3.4% of residents age 70 or older reported using marijuana in the past month.

“Grandma is certainly the new face of cannabis,” said Stephanie Gluchacki, president of clinical operations for Canna Care Docs, which has 11 medical offices in Massachusetts.

She said about 24%, nearly one out of four, of their patients are ages 60 to 74, and another 10% are over 75.

“It’s definitely not the demographic one would anticipate to see,” she said.

Ann Brum, spokeswoman for MedWell Health & Wellness, another clinical group that certifies patients with qualifying conditions for medical marijuana eligibility, said baby boomers, roughly ages 55 to 73, and older patients are a growing and important part of the marijuana market.

She highlighted a market trend report by BDS Analytics, which found that two out of three baby-boomer consumers use cannabis for medical or health reasons, often to replace prescription medication.

“They’ve just had it with polypharma, med after med,” Ms. Brum said.

Another recent survey by researchers at Worcester-based Cannabis Community Care and Research Network and the University of Massachusetts at Dartmouth reported that medical marijuana consumers ages 50 or older primarily use cannabis to treat chronic pain, anxiety, depression, insomnia and arthritis.

Approximately one in five survey respondents reported that cannabis helped them reduce use of opioids. Nearly a third reduced their use of other medications.

Medical marijuana clinicians and dispensaries are targeting their outreach to tap into this growing demographic.

MedWell, which has brick-and-mortar offices elsewhere in the state, offers local pop-up medical cannabis evaluation and certification clinics, such as one scheduled for Aug. 11 at the Hilton Garden Inn in Worcester.

MedWell clinicians also go into assisted living and retirement communities, or will conduct home visits to evaluate and educate patients on medical cannabis, according to Ms. Brum.

Canna Care Docs offers lunch and learn sessions at senior centers. A nurse practitioner discusses legal and health-related aspects of cannabis, but evaluations and certifications aren’t conducted as part of the seminars.

Medical marijuana dispensaries are invited to participate in these educational sessions as well.

“These Q&As allow for open conversation without judgment,” Ms. Gluchacki said.

There are several common themes among seniors, according to Ms. Gluchacki. They’re seeking relief from chronic pain, especially arthritis; they’re looking to cannabis as a sleep aid; and they’re interested in cannabis’ role in curbing Alzheimer’s symptoms, for which there is some, but not rigorously tested, association, according to the Alzheimer’s Association.

Seniors are also cost-conscious and look to cannabis as a cheaper alternative to prescription medication, she said.

Several in the marijuana industry said seniors were less likely to rely on the internet for information, preferring to have printed material to share with family and friends, and to rely on word-of-mouth.

Ms. Edelstein arranged for a lunch and learn with Canna Care Docs and Curaleaf in May.

Worried at first about what the town would think, she said, “I ran this program with a nervous stomach. And it was amazing.”

Several seniors pursued medical marijuana after that presentation, but most were still reluctant to talk publicly about their use.

“There’s a stigma that goes with it, and that’s a shame,” Ms. Edelstein said. “If it can help somebody, I say, shout it from the rooftops.”

Northbridge Senior Center has scheduled a cannabis information session with Canna Care Docs for Sept. 4.

Uxbridge Senior Center is exploring hosting an information session, according to Director Lisa Bernard.

Last year, Worcester Senior Center hosted a presentation on medical marijuana by Dr. Alan Erlich of University of Massachusetts Medical School, according to Senior Center Director Amy Vogel Waters. In addition, there will be a presentation on the use of CBD oil at the Senior Center on Sept. 19 to be made by pharmacist Vrushank Patel, manager of Auburn Pharmacy & Home Health Care.

Local retail pot shops and medical marijuana dispensaries have taken notice of the older customers who come in.

“It’s what we’re seeing,” said Caroline Frankel, owner of Caroline’s Cannabis in Uxbridge, a recreational marijuana retail store. “About 15% to 20% of our customers are over 65.”

Older adults were looking for a healthier alternative to prescription medication, she said. “The biggest thing: Seniors can’t sleep.”

Some seniors opt to buy recreational marijuana for health treatment rather than go through the expense and procedures for medical certification and registration with the state, Ms. Frankel said.

She’s also seeing older “hard-core enthusiasts who are excited to have an outlet to purchase” marijuana legally.

“In Worcester in particular, we’ve really got a good 50-plus demographic and we see that increasing,” said Matthew J. Huron, founder and CEO of Good Chemistry, which has a medical marijuana dispensary and adult-use retail store at 9 Harrison St.

He said older customers often look for advice on products, which have proliferated from what was available 30 or 40 years ago. “They have more patience, are a little more eager to learn,” he said.

Westword, a publication based in Denver, awarded Good Chemistry’s Colorado locations the “best dispensary to take your grandmother” in 2017. The award highlighted Good Chemistry’s easy-to-understand description of different cannabis strains’ effects.

“We’re very proud of that,” said Mr. Huron.

Kate Steinberg, program manager of Curaleaf Cares, said outreach in senior centers was often the first place the company connects with many seniors.

When they come to a dispensary, located in Oxford and Hanover, they can have an extensive personal consultation and are sent home with a few products to try.

“We love that experience and knowledge we gain to maybe help other seniors,” Ms. Steinberg said. “They never have to go home, look in their bag and say, ‘Now what?’ ”

“Education is a hallmark of our company. People are overwhelmed by the number of different products,” said Katrina Yolen, Curaleaf’s senior vice president of marketing.

Tyler Coste, dispensary manager at The Botanist, a medical marijuana dispensary at 65 Pullman St., Worcester, said 35% of The Botanist’s customers are 65 or older.

He said tinctures, which are often heavily based on the nonpsychoactive CBD component of cannabis, were one of the largest-selling products for older adults. Transdermal patches and roll-on ointments were also popular.

“Easily the thing we hear the most is, ‘I don’t want to get high,’ ” said Ross Riley, outreach manager at The Botanist.

The Botanist started holding outreach seminars in Sterling, according to Mr. Riley, first for the general population and then one for seniors.

Word-of-mouth spread. “The more we’ve seen, they’ve told their friends, they go get (medical marijuana) cards,” Mr. Coste said. “That blows me away. That’s such a rewarding feeling.”

The need for information about today’s wide array of cannabis for the Woodstock generation was a theme cited across the industry.

A magazine publisher in Western Massachusetts recently launched Different Leaf, a print-only quarterly billed as a journal of cannabis culture, targeted to readers 45 and older.

“There are 150 to 200 products in every dispensary. It’s going to be overwhelming,” said Publisher and Editor-in-Chief Michael Kusek of Northampton, who previously ran an arts and culture magazine.

Mr. Kusek, 50, said after talking to people in the industry, he learned, “the overwhelming amount of their customer base were 50-plus.” But existing marijuana media was either business-to-business or targeted to young adults.

“My goal is to be a trusted source about cannabis,” he said.

Not everyone is pleased with the growing interest in marijuana among older adults.

“I have tremendous respect for the brain. I’m not in favor of people putting things in their body that potentially adversely affect the brain,” said Dr. Anthony J. Rothschild, professor of psychiatry at UMass Medical School.

Dr. Rothschild was one of more than 40 pediatricians, mental health and addiction clinicians and scientists in Massachusetts who signed in May a statement of concern about marijuana policy in Massachusetts.

He said the impact of THC, the psychoactive component of cannabis, on older adults is just not known. Some studies have shown harmful effects, including cognitive problems and decreased functioning on neuropsychological testing.

“Older people’s brains are more sensitive to things,” he said. “As you age, there’s loss of brain tissue. We don’t have enough data to say if it (marijuana) is bad or good.”

He said more research needed to be done, particularly on conditions such as Alzheimer’s, for which data are conflicting.

Dr. Rothschild was also concerned about people driving under the influence of marijuana and about self-medicating, similar to alcohol use, instead of seeking a doctor’s advice for conditions such as depression and sleep problems.

There’s big money in marijuana too, in industry profits as well as in tax revenue for the state and municipalities. “That’s something about this that makes me nervous,” he said.

“What bothers me,” Dr. Rothschild said, “is the enthusiasm by which a large part of the population is embracing this.”