World Guinness World Records oldest man, who said secret to long life was smiling, dies at 112 February 25, 2020Adrianna Rodriguez, USA TODAYComments Off on Guinness World Records oldest man, who said secret to long life was smiling, dies at 112 Chitetsu Watanabe was presented the certificate as the world's oldest living man by Guinness World Records in Niigata, Japan, on Feb. 12.