Japanese, who believes in smiling, is oldest living man: Guinness

Happiness could be the key to longevity, as a Japanese national who crossed the 100-year mark has shown. And happy people are forever smiling, something which Chitetsu Watanabe believes in doing. No wonder he has lived for a good 112 years.

Watanabe, who was born on March 5, 1907 in Niigata, north of Tokyo, was officially crowned the world's oldest male at his nursing home in the city, Guinness World Records said on Wednesday.

Chitetsu Watanabe celebrates after being awarded as the world's oldest living male by Guinness World Records, in Joetsu. AP

The previous record holder, Masazo Nonaka, another Japanese, died last month at 112 years and 266 days. The oldest living person is also Japanese, Kane Tanaka, a 117-year-old woman.

Watanabe, who is married with five children, said the secret to longevity is to "not get angry and keep a smile on your face."

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Until about a decade ago, Watanabe used to do bonsai, the Japanese traditional art of raising small sculpted trees, and had his work exhibited. These days, he loves desserts such as custards and cream puffs, Guinness said.

Watanabe graduated from agricultural school and then moved to Taiwan to work at Dai-Nippon Meiji Sugar on sugarcane plantation contracts.

He lived in Taiwan for 18 years. He married Mitsue and they had five children, Guinness said in a statement.

After the end of World War II, Watanabe returned to Niigata and worked for the prefectural government until retirement. He also grew fruit and vegetables on the family farm.

Japan has one of the world's highest life expectancies and has been home to several people recognised as among the oldest humans to have ever lived.

They include Jiroemon Kimura, the longest-living man on record, who died soon after his 116th birthday in June 2013.

The oldest verified person ever — Jeanne Louise Calment of France — died in 1997 at the age of 122, according to Guinness.