Q I recently celebrated my 90th birthday. We had a great celebration with family and friends. I don’t read a lot about 90-year-olds. What do we know about this group and what can we learn from them? Thank you.

— M.H.

A Happy birthday to you! What a wonderful milestone, made even more special in celebration with family and friends. The Bureau of Labor Statistics classifies the oldest age category as 75 and up.

We have luminaries who are recognized for their talent and ongoing contributions who are in their 90s. Among them are Norman Lear, Rita Moreno, Mel Brooks, Dick Van Dyke and “Dr.” Ruth Westheimer, to name a few.

To find out some facts, take this brief true-false quiz.

1 Currently, 1 million people have celebrated their 90th birthday.

False. Actually, it is 2 million. That number has almost tripled over the past three decades and is expected to more than quadruple over the next four decades, according to the U.S. Census Bureau.

2 A person between 90 and 99 is called a nonagenarian.

True. Here is the sequence. A person between 80 and 89 is an octogenarian; one between 100 and 109 is a centenarian. And a person 110 or older is called a supercentenarian.

3 Among those 90 and older, men outnumber women because they experience less stress.

False. In 2019, women outnumbered men — 34% of women reached 90, while for men it was 16%. That translates to about 1 out of 3 women and 1 out of 6 men.

4 Research has identified certain behaviors that are obstacles to reaching age 90.

True. A study published in the Archives of Internal Medicine identified smoking, diabetes, obesity and high blood pressure as behaviors and conditions that can prevent reaching age 90.

5 About 50% of those 90 and older suffer from dementia.

False. It’s closer to 33%.

6 Although there is no known cause or cure for dementia, we know about some interventions.

True. The National Institute on Aging reports “encouraging but inconclusive” evidence on the effectiveness of three types of intervention: increased physical activity, blood pressure control and cognitive training. Evidence of effectiveness of other interventions such as diet and medications were not as strong.

7 A schedule of daily practices can increase our chances to live to age 90.

True. Dr. Thomas Perls, professor of medicine at Boston University School of Medicine and director of the New England Centenarian Study, identifies five practices: Manage stress; get good sleep; make healthful food choices (such as the Mediterranean diet); exercise often, with strength training and aerobic work — even just 10 minutes a day; and don’t smoke.

8 Many who reach 90 and beyond say they are in good health.

True. That’s despite experiencing chronic diseases and even some disability. These older adults adapt and remain positive.

9 Certain personality attributes can help you reach 90 and beyond.

True. These include resilience, engagement and strong social support, and having confidence in yourself.

10 Research from the “Blue Zone” studies indicates that centenarians share common lifestyle characteristics.

True. These include moving naturally in the outdoors, having a sense of purpose, stopping eating when they are 80% full, belonging to a faith-based community, and having strong connections with family and friends, to name a few.

Clearly, not everyone lives a life of health in their 90s. Many are in long-term care facilities, are homebound or are living with serious chronic conditions. However, we are living in a new reality where the chances of living into your 90s with relatively sound health are good.

What can we learn to increase our chances to live to age 90? Genetics plays a significant role. Yet we cannot underestimate the influence of lifestyle choices and behavior; that’s our sphere of influence. Of course, a little luck helps. Note there are economic, social and geographic disparities in who gets to live this long life. That’s another column.

M.H., thank you for your good question. Enjoy your 90s and know that today’s 90-year-olds are role models for the next generation. Stay well, everyone.

“How do we change the world? One act of random kindness at a time.” — Morgan Freeman

Note: In my previous column, the Silent and “Greatest” generations were incorrectly said to be the same group. The Greatest Generation refers to those born between 1901 and 1927, while members of the Silent Generation were born between 1928 and 1945.

Helen Dennis is a nationally recognized leader on issues of aging and the new retirement, with academic, corporate and nonprofit experience. Contact Helen with your questions and comments at Helendenn@gmail.com. Visit Helen at HelenMdennis.com and follow her on facebook.com/SuccessfulAgingCommunity