100-Year-Old Japanese Doctor Shares Secrets to Longevity, Health, and Purpose

The 100-Year-Old Doctor Who Still Treats Patients in Japan: Lessons and Secrets to Longevity and Purpose

In a world where most people dream of retirement long before hitting 70, Dr. Teru Kasamatsu of Japan is rewriting the script on what it means to age. At 100 years old, she still puts on her white coat three days a week to see outpatients at her family’s hospital in Wakayama Prefecture. Her secret? A mix of vegetables, number puzzles, piano practice, and a calm attitude toward life. But her story isn’t just about longevity, it’s about resilience, purpose, and a deep love for her community.

Born in 1925 in what is now Kinokawa City, Wakayama Prefecture, Teru Kasamatsu was the fourth of five siblings. Her journey into medicine began in high school, shaped by her father’s advice: women needed a profession to be independent, especially after witnessing so many widows during the war years.

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By 1948, she had graduated as a doctor, and at 24, she married surgeon Shigeru Kasamatsu. Together, they ran Kasamatsu Hospital, which had been in the family since 1909. It wasn’t just medicine she mastered, she did everything from writing prescriptions and assisting in surgeries to bookkeeping. When the hospital needed a cook, she went the extra mile and earned a cooking license in her 30s. At the peak of her career, she saw as many as 120 patients a day, often sacrificing sleep to help with emergency surgeries. “I did everything,” she recalled, and it’s this willingness to learn, adapt, and serve that seems to define her century-long journey.

The Secrets to Her Longevity

So, how does a centenarian doctor still keep up with patients and medical literature? According to Dr. Kasamatsu, it comes down to a simple but consistent lifestyle:

• Eat your vegetables first: She prioritizes spinach, broccoli, cabbage, and okra, saying vegetables help keep blood sugar in check.
• Cut back on salt: A small but crucial choice for heart health and longevity.
• Keep your mind sharp: She spends one to two hours daily on number puzzles to prevent dementia.
• Stay active and curious: She started piano lessons at 70 with her husband and continues to play.
• Travel and friendships: Before the pandemic, she loved traveling with friends.
• Don’t overthink life: Her philosophy is beautifully simple, “Things have worked out so far even without overthinking. I’ll just take it easy.”

It’s not just about physical health for her, it’s about mental resilience and emotional balance.

Living Proof of Purpose

Even after battling cancer and losing her husband, Dr. Kasamatsu never slowed down. She now lives alone in a house next to the hospital, walking without the aid of a cane, and continues to serve her patients with empathy. Her son, Dr. Satoshi Kasamatsu, who now leads the hospital, describes her gift perfectly: “She’s good at creating an atmosphere where it’s easy to talk, which helps patients open up.” That human touch, combined with her medical expertise, keeps her patients coming back, not just for treatment, but for the comfort she radiates.

Dr. Kasamatsu’s story is inspiring, but it’s also part of a larger picture. Japan is home to a record 99,763 centenarians as of September 2024, marking 55 consecutive years of increase. Remarkably, 88% of them are women. The country’s oldest woman, Shigeko Kagawa, is 114, while the oldest man, Kiyotaka Mizuno, is 111. Among Japan’s 340,000 practicing physicians, at least 86 are 98 years or older, proving that age is no barrier to service when health and purpose align.

A Lesson for the World

Dr. Teru Kasamatsu is more than a centenarian physician, she’s living proof that longevity isn’t just about genetics or luck, but about habits, mindset, and community service. Her advice may sound simple, eat vegetables, keep your brain active, don’t stress over the uncontrollable, but when practiced daily over decades, it has clearly built a foundation of resilience.

As societies around the world grapple with aging populations, perhaps we can take a page from Dr. Kasamatsu’s life: find joy in service, keep learning, and never underestimate the power of a vegetable-rich plate and a curious mind.