Gehman graduated from the American College of Naturopathy and Chiropractic in 1925.[1] He obtained a doctorate in natural philosophy in 1931. He was a vegetarian and wrote articles for the American Vegetarian-Hygienist and the Health and Strength magazine.[1]
Gehman was Chairman of the First American Vegetarian Convention held at Lake Geneva, Wisconsin in 1949.[2] He was Vice-President of the International Vegetarian Union (1960–1977), he was also President of the American Naturopathic Association.[3] Gehman was Benedict Lust's successor. He wrote an authorized biography of Lust, but the work was never published.[4] Gehman worked as an associate editor for Bernarr Macfadden's Physical Culture magazine. He founded his own naturopathic resort near Harrisburg, Pennsylvania.[5] Gehman was a founding member of the American Natural Hygiene Society.[6]
Gehman was an anti-vaccinationist. He commented that naturopaths do not believe in "vaccination, inoculation, contagion, infection or drugs of any kind."[2] His best known work Smoke Over America, examined the dangers of tobacco smoke. It was negatively reviewed in The Sanitarian journal as "poorly organized, unscientific, over-written."[7] He was secretary of the Citizens Medical Reference Bureau from the 1930s–1950s, which had connections to the Anti-Vaccination League of America.[8] He recommended clean living, exercise, fasting and a vegetarian diet to treat cancer, he commented that "the cure of cancer is in simple natural physical culture living".[9]
Gehman was an amateur wrestler, under the name Jim Mercer.[1] His brother was "Atomic" Marvin Mercer, a heavyweight wrestling champion.[10][11]
^Colgrove, James. (2006). State of Immunity: The Politics of Vaccination in Twentieth-Century America. University of California Press. p. 55, p. 267. ISBN0-520-24749-3