Does working in freight transportation contribute to longevity? There's no scientific evidence to support that, but we wonder if working on the railroad had something to do with making Walter Breuning the world's oldest man. The 113-year-old Great Falls, Mont., resident is a retired career rail worker, according to the Transportation Communications Union (TCU).

Breuning, who was a clerk for the BNSF, became a TCU member in 1919. In a video posted on TCU's website, he said his early years on the railroad were tough because of a drought that killed livestock and caused a shortage of feed. Breuning recalled that hundreds of workers were laid off as a result of a decline in cargo volumes.

Today, Breuning lives in a retirement home, where he exercises daily and gets around with the aid of a walker and a motorized scooter. He keeps his mind sharp through listening to the news and constant learning. "If you don't learn something new, you've lost a day," he said in a television interview.

The title of world's oldest living man was bestowed last month by the Guinness Book of World Records. Breuning intends to keep that crown for a while. "The way I feel, I'll be here a long time yet," he said.