Longevity secrets of 100-year-old doctor who still sees patients 3 days a week

At 100 years old, Dr. Teru Kasamatsu of Wakayama Prefecture, Japan, still sees outpatients at her family-run Kasamatsu Hospital three days a week, proving that age is no barrier to dedication. The hospital, located in Kainan City, has been a central part of Kasamatsu’s life for nearly 80 years since its founding in 1909.

Born in 1925 in what is now Kinokawa City, Kasamatsu attributes her remarkable longevity to a vegetable-rich diet and keeping her mind active. “Eat lots of vegetables, like spinach, broccoli, cabbage, and okra. They help regulate blood sugar and are very good for you,” she told Yomiuri Shimbun. She also emphasizes moderating salt, eating vegetables first, staying mentally engaged, and not worrying over things beyond her control. “Things have worked out so far even without overthinking. I’ll just take it easy,” she added, as reported by Wakayama Shimpo.

Kasamatsu decided to become a doctor in high school, encouraged by her father, who wanted her to be self-reliant after witnessing many women lose their husbands during the war. She graduated in 1948 and married surgeon Shigeru Kasamatsu at age 24. When Shigeru took over the hospital from his father, Teru began working alongside him, balancing hospital duties with raising three children.

She recalls days seeing up to 120 patients and assisting in emergency surgeries, often sleepless. She managed everything—from examinations and prescriptions to bookkeeping—and even obtained a cooking license in her 30s to help when the hospital needed a cook.

Today, the hospital is run by her son, Dr. Satoshi Kasamatsu, 68, who praises his mother’s ability to “create an atmosphere where it’s easy to talk,” helping patients open up. Despite her busy life and a period of hospitalization for cancer, Teru Kasamatsu has maintained an energetic lifestyle.

She began learning piano at 70 with her husband and continues to play daily. Since her husband’s passing, she has lived alone in a house adjacent to the hospital, moving around without a cane. Her daily routine includes one to two hours of number puzzles to help prevent dementia and reading medical literature to stay up to date. She has no intention of retiring, according to Wakayama Shimpo.

Kasamatsu’s longevity coincides with a broader trend in Japan, where the number of centenarians reached 99,763 in September, marking 55 consecutive years of increase, according to the Ministry of Health. Women make up 88% of the centenarian population, with the oldest being Shigeko Kagawa, 114, from near Nara City. The oldest man is Kiyotaka Mizuno, 111, from Iwata. Of the approximately 340,000 practicing physicians nationwide as of the end of 2022, 86 are aged 98 or older.