Tokyo: The world's oldest man celebrated his 112th birthday today with a healthy Japanese breakfast of rice, miso soup and seaweed, saying he wanted to live forever.

Tomoji Tanabe, who has been the world's oldest man since January this year, lives with his son and family in Japan's southern prefecture of Miyazaki. He keeps a diary and reads the newspaper every day. "I want to live indefinitely. I don t want to die," he said as he marked his birthday, Kyodo News reported.

Tanabe, a teetotaller who has repeatedly said that avoiding alcohol is a secret of his longevity, was given a certificate from the Guinness Book of World Records by the mayor of his local municipality in June.

Japan has the largest population of centenarians in the world. The number of Japanese aged at least 100 years old is expected to top 30,000 by the end of September, the health ministry said in a recent report.

The Japanese people's renowned longevity is often attributed to eating the country's traditional healthy food, despite the hectic lifestyle many lead in the big cities. But the longevity is also presenting a headache as the country has one of the lowest birthrates, raising fears of a future demographic crisis as a smaller pool of workers supports a mass of elderly.