In the year in which Misao Okawa was born in Osaka, Queen Victoria was still on the British throne.

Okawa, already recognised as the oldest person in the world, is due on Wednesday to celebrate her 116th birthday - and attributes her longevity to eating well and sleeping at least eight hours every night, with the occasional nap thrown in for good measure. "You have to learn to relax."

The daughter of a kimono-maker from Japan's second city, Okawa assumed the title of the oldest person in the world after the death of 116-year-old Jireomon Kimura in June last year. Experts say it is no coincidence that both record-holders are from Japan, which was home to 54,397 centenarians on the last Respect for the Aged national holiday in September - including 282 super centenarians, those who have bypassed the age of 110.

Tomohito Okada, the head of the Kurenai retirement home where she has lived for the past 18 years says: "She insists that her favourite meal is sushi, particularly mackerel on vinegar-steamed rice, and she has it at least once every month."


Asked about her happiest moments, Okawa recalls her marriage in 1919 to Yukio Okawa and the birth of their three children. Her surviving son and daughter are 94 and 92. She also has four grandchildren and six great-grandchildren. She says the saddest time of her life was the death of her husband in June 1931 - 83 years ago.

The average lifespan for a Japanese woman is now 85.9 years, with women also accounting for 87 per cent of the nation's centenarians. A Japanese man can expect to reach 79.6 years old. Experts put Japanese longevity down to a comprehensive healthcare system, the support of the community, encouragement to remain physically active until they are quite elderly, a sense of being part of a family and a healthy diet that has traditionally been heavy in fish, rice, vegetables and fruit.

But Yasuyuki Gondo, an associate professor at Osaka University, who specialises in geriatric psychology, says: "When we surveyed centenarians, we found that the majority have enjoyed good mental health throughout their lives and have developed psychological adaptations to their situations as they have got older."

Those studies suggest that people with a strong will, are outgoing and have a sense of curiosity live longer.