World ‘Keep a smile on your face’: World’s oldest man shares secret to longevity at 112 February 12, 2020Adrianna Rodriguez, USA TODAYComments Off on ‘Keep a smile on your face’: World’s oldest man shares secret to longevity at 112 Guinness World Records confirmed Chitetsu Watanabe, 112, of Japan as the world's oldest living man. His secret: Smile, don't be mad, eat cream puffs.