Today marks the 116th birthday of the world's oldest person, Misao Okawa. She now holds the title of "world's oldest person" following the June 12, 2013 death of 116-year old Japanese man Jiroemon Kimura.

The supercentenarian was born in Osaka in 1898, a time when Queen Victoria was still on the British throne, and the Spanish American War was raging.


Misao Okawa is pictured here with her older sister, circa 1900.

The fact that record-holders Okawa and Kimura are from Japan is no coincidence, as the country is home to 54,397 centenarians, on the last Respect for the Aged national holiday in September - including 282 super-centenarians, who have achieved the ripe old age of 110.

So what's Mrs. Okawa's secret to longevity?

Sushi!

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

But more importantly, Okawa advises to eat well, sleep enough, and learn to relax. “Eat and sleep and you will live a long time,” she said in a message to The Telegraph. “You have to learn to relax.”

Okada also added that “Mrs Okawa eats three large meals a day and makes sure that she sleeps eight hours a night.”

People with good mental health also tended to stay alive for longer, according to Yasuyuki Gondo, an associate professor at Osaka University who specializes in geriatric psychology.

“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,” he told The Telegraph.

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