Israel Kristal lived through the tumult of two world wars, lost his family in the Holocaust and escaped death in the Auschwitz concentration camp. He then built a new life in Israel. On Friday, at the age of 112 years and 178 days, he was declared the oldest man in the world.

The announcement was made by Guinness World Records, which said it had verified Mr. Kristal’s age with the assistance of the Gerontology Research Group in Los Angeles and Jewish Records Indexing – Poland, an organization that preserves records of the history of Polish Jews.

“I don’t know the secret for long life,” said Mr. Kristal, who lives in Haifa, Israel, according to a statement issued by Guinness World Records.

“There have been smarter, stronger and better looking men then me who are no longer alive,” he added. “All that is left for us to do is to keep on working as hard as we can and rebuild what is lost.”