There is no age limit on learning.

Judy Elstein — an 82-year-old former English teacher and resident of Cambridge — knows that to be true. Nowadays, she spends her time in classes at the Harvard Institute for Learning in Retirement, or HILR, a program composed of retired and semi-retired professionals who share a commitment to learning.

“I’ve always been very excited about reading. I’ve always read many, many books. More than most people,” Elstein said.

Boston is home to several such programs, most run by colleges and universities such as Harvard, Tufts University and Boston University. The fees range from $75 to around $500 a semester. And participants and experts alike say the mental and social benefits serve to bolster wellness in those who are getting on in years.

Tess O’Toole, assistant dean and director of the HILR, described it as a robust liberal arts program that is 100% produced by participants as part of peer learning.

I think it’s a collective enterprise, and I think that’s what’s really special,” O’Toole said.

The institute offers about 75 courses each semester to about 500 retirees, O’Toole added.

And when you’re doing it in a context where there’s no assessments,” she said, “where it’s learning for learning’s sake and you’re doing it with your peers, that’s very exciting for people.

Learning in elderhood

Louise Aronson, a professor of medicine in the division of geriatrics at the University of California San Francisco, wrote the book “Elderhood,” in which she takes a close-up look at how to reimagine life and medicine for older people.

We act as if there’s just children and adults,” Aronson said. “And there’s this other phase which, for most of us at this point in life, our elderhood will be longer than our childhood.”

Aronson said elderhood is the analog to childhood and adulthood.

“One of the biggest determinants of a healthy old age is how much education you have. And that’s why I argue that you can’t really talk about aging without including people across the lifespan,” Aronson said.

Another big determinant of a healthy old age is where you live in the country.

“And you can see across regions and demographic groups that the people, regardless of income, if they’re more motivated, you know, have a sense of purpose,” Aronson said.

'Feeling pretty spry’

Ross Neisuler, a retired octogenarian who lives in Cambridge, attends and teaches courses at the HILR.

I’m 84 and I’m feeling pretty spry and younger every year, I think,” Neisuler said.

Neirsuler takes a variety of courses, including one this year about the resilience of Japanese Americans who were rounded up into incarceration camps during World War II.

Like many other attendees, Neisuler has built his social life around HILR.

“You have to want to have your world opened up a bit,” Neisuler said.

Neisuler is in his 19th year taking and teaching classes. As a widower, he said an important aspect or secret to growing old is never allowing boredom to settle into your life. And taking fascinating classes keep boredom at bay.

Prudence King, who is 84, takes classes at the Osher Lifelong Learning Institute at Tufts University. King lives in a retirement community in Lexington.

Osher Lifelong Learning Institutes are found on 125 college and university campuses across the U.S. Each is different and distinctive offering courses and activities for older adults, “interested in learning for the joy of learning,” according to their website.

I get a kick out of being an octogenarian. Because first of all, you can get away with being somewhat uninhibited.
Prudence King, Lexington, Mass.

“I get a kick out of being an octogenarian. Because first of all, you can get away with being somewhat uninhibited,” King said.

At the Osher Lifelong Learning Institute at Tufts University, associate director Callan Moody said the average age of their program participants is 77, with the oldest member at age 93.

“I think just to be a good community member is taking care of the whole community,” Callan said.

The Pew Research Center reports the number of Americans who live past the age of 100 is projected to more than quadruple over the next three decades.