While Sanders has far left policies, he's always vocal about his plans for the future. Sander's main goal is to return America to the working class, and health care is one of the ways he plans on doing it. The Universal Health Care act is already keeping costs down. Sanders will continue this.
Yes, if Bernie Sanders is elected President he will help stop rising health care costs because he has publicly stated that health care is a right not a privilege. Although Sanders hasn't formally detailed his health care strategy, Sanders has voiced repeatedly that he believes that Americans should have access to affordable and quality health care.
Although Bernie Sanders is well intentioned, he will not be able to cut down costs due to hospital corruption. The hospitals and other care centers have been price gouging as a standard for years. No one has addressed this. Walgreens overcharges Medicare almost every year with impunity. They pay a big fine while still pocketing massive profits so there's no deterrent. Healthcare is too out of control to pull them back in line quickly.
If Bernie Sanders is elected president of United States, it will not protect Americans against rising healthcare costs because it has already been researched and proven that his plan will, in fact, raise costs. Not only will cost rise, they will increase significantly. Electing Bernie Sanders will be a disaster for this country.