Can you replace 17in rims to 15in rims?

[A]

I have had to replace 3 steel rims in the past two years thanks to potholes. I was told that it was because of the low profile 17in. rims/tires. Apparently the less tire around the rim the higher the chance for bending the steel. The car is a 2008 and came standard with the 17in. wheel and tire. So my question is can I go smaller to absorb more of the shock of the potholes. My old car had 15in and I never had these problems before. TY