George Johnson, considered California’s oldest living person at 112 and the state’s last surviving World War I veteran, had experts shaking their heads over his junk food diet.

“He had terrible bad habits. He had a diet largely of sausages and waffles,” Dr. L. Stephen Coles, founder of the Gerontology Research Group at the University of California, Los Angeles, said Friday.

The 5-foot-7, 140-pound Johnson died of pneumonia Wednesday at his Richmond home in Northern California.

“A lot of people think or imagine that your good habits and bad habits contribute to your longevity,” Coles said. “But we often find it is in the genes rather than lifestyle.”

Johnson, who was blind and living alone until his 110th birthday when a caregiver began helping him, built the Richmond house by hand in 1935. He got around using a walker in recent years.

Johnson was the only living Californian considered a “supercentenarian,” a designation for those ages 110 or older, Coles said. His group is now in the process of validating a Los Angeles candidate who claims to be 112 years old.

Coles participated in an autopsy Thursday that was designed to study Johnson’s health.

“All of his organs were extremely youthful. They could have been the organs of someone who was 50 or 60, not 112. Clearly his genes had some secrets,” Coles said.

‘A mysterious case’

“Everything in his body that we looked at was clean as a whistle, except for his lungs with the pneumonia,” Coles said. “He had no heart disease, he had no cancer, no diabetes and no Alzheimer’s.

“This is a mysterious case that someone could be so healthy from a pathology point of view and that there is no obvious cause of death.”

The family was in favor of an autopsy. Relatives said Johnson wanted them to allow it if it would help science.

Born May 1, 1894, Johnson’s father managed the Baltimore and Ohio Railway station in Philadelphia.

Johnson was working in 1917 as a mail sorter for the U.S. Post Office when he was drafted into the Army. The war ended a year later, and he never served in combat.

Two years later, he and his wife moved to Northern California.

“It was a great adventure in those days. We were young and wanted the experience,” Johnson said in a March interview with the Contra Costa Times.

The couple settled in Fresno and remained there until 1935, when they bought property in Richmond. They used lumber salvaged from dismantled buildings to build their house.

During World War II, Johnson worked at the Kaiser shipyard in Richmond and later managed the heating plant at Oak Knoll Naval Hospital in Oakland.

He remained in good health and continued driving until he was 102, when his vision began to fail.

Johnson’s wife died in 1992 at the age of 92. The couple had no children.