Maria Rooth, Gunilla Andersson and Ann Louise Edstrand scored two goals each for Sweden at the Turin Esposizioni arena.
Erika Holst and Nanna Jansson rounded out the scoring with singles for Sweden which led by period scores of 3-0 and 8-0.
The Swedes scored four goals on the powerplay and one while shorthanded.
It was the second-straight one-sided loss for Olympic debutant Italy who have been outscored 27-0 and outshot 118-9 in the preliminary round.
Sweden next faces top seed Canada while Italy wraps up their tournament by taking on Russia.