A 100-year-old woman's recipe for a long life includes helping others, not missing a day's work, and wearing red

• Centenarian Ruby Cole turns 101 this month — and will make sure she looks her best for the occasion.
• She told Insider that one of the secrets to a long life is putting the needs of other people first.

Ruby Cole was born in 1922 — the year that the US Supreme Court upheld women's right to vote, the Lincoln Memorial was completed and insulin was used to treat a diabetic for the first time.

The retired nurse lived through historical events including the Great Depression, World War II and the civil rights movement.

She told Insider that she "loved her life" and kept a "positive outlook" to stay "happy."

Cole is the latest in a line of centenarians who have given Insider their tips on longevity. It follows the success of author Dan Buettner's Netflix series, "Live to 100: Secrets of the Blue Zones."

Buettner and others had identified five different pockets of the world where people live much longer than average. They include Loma Linda in California and the Nicoya Peninsular in Costa Rica.

It appears that Cole, who has lived in states including Alabama, North Carolina, Michigan, and Maryland, took her own private Blue Zone wherever she went. She — and two of her closest relatives — explained how.

Her life has been devoted to others

Cole, who sits on the board of a foundation that helps people navigate the US health system, said one of the secrets to happiness and longevity is serving others.

"You have to be kind, loving, and serviceable," the centenarian said. "It works both ways because you feel good when you're helping other people feel good."

The devout Christian said that she entered the nursing profession at the age of 17 — qualifying at 21 — and didn't officially retire until she was 85. During that time, her niece, Paula Martin said, she didn't call out sick for a single day.

"Miss Ruby didn't want to let people down," Martin said. She said that Cole specialized in pediatric nursing and helped establish a baby clinic in Detroit, Michigan.

"One thing she imparted on us is that giving of yourself makes you happy," Martin told Insider, adding, "And happiness is the key to a life well lived."

She has eaten regular meals throughout her life

Cole said that she ate three balanced meals at the same time every day.

"Eating properly means that you can't miss a meal," she said.

The 100-year-old said that people should finish what's on their plate — a habit she learned at boarding school. She said it helped her stay full and not give in to the temptation of snacking between meals.

She warned against spicy foods that are difficult to digest — especially "late at night" — and recommended a "simple diet" made up of protein, starch, and vegetables.

Her nephew, David Luckett, with whom Cole lives near Washington D.C, told Insider that the former resident of a fruit farm tells the family to eat as much fruit as possible.

"We call her our professional watermelon selector because she always knows which ones are ripe and sweet," he said.

She exercises on a daily basis

The 100-year-old's past exercise regime revolved around walking.

She said that she never used "fancy" machines at the gym and preferred to feel the "fresh air on my face" by striding through her neighborhood every morning.

"I'd get up early before work and meet a friend to walk two miles," Cole said. "We never missed a day, even when the weather was bad," she added.

These days, she said she does "little leg taps" for 25 beats on each side while leaning on her walker. Then, when she is seated, she raises both her arms 25 times to work on her flexibility.

"With my arthritis, I get a little sore," she told Insider. "But I try and do as much as I can to keep myself moving."

Matching accessories are the key to looking her best

Cole said that she subscribes to the belief that "when you look good, you feel good."

Martin said that she is proud of her appearance and carefully selects her outfits before going out.

"She loves to match," her niece said. She said that she particularly likes bright colors — she wore red to her 100th birthday celebration in October 2022, which was attended by 100 family and friends.

The centenarian said that her favorite accessories were handbags and jewelry. "They have to compliment each other," she said, adding, "I like to be matching."

Martin said that she never forgets to put her hair in rollers to give volume. "She's very meticulous, but she's always been a natural beauty."

Watching sports, the news, and 'Wheel of Fortune' keeps her informed

Cole, a longtime fan of the Detroit Lions, enjoys watching football, baseball, and basketball on TV. "I find it exciting," she told Insider.

Another interest, she said, was US politics. "It's important because you've voted for these politicians and have to live under their decisions," the 100-year-old said.

"You need to make sure they keep listening to you," she added.

Meanwhile, Luckett said that he was constantly astounded by his aunt's general knowledge. "Miss Ruby watches 'Wheel of Fortune,'" he said. "She hardly ever gets an answer wrong. She'd make a great contestant."