Why is there white lines along the edges of a curved surface

As seen in the screenshot below, I have created a model which is a cylinder shape. However when the model has its back to the light source / is in the shade this happens. There are light white lines on the edges of the smooth surface. As you can see this is only effecting the top of the model. The bottom half appears completely smooth. The top half which is affected appears normal when directly facing the light. Unfortunately as you can see this take away the illusion of the surface being round.

How can i fix this, is it a lighting problem or an issue with the model?

The problem goes away when i take the ambient occlusion post process off and it makes perfect sense that that would cause it but I need this on the overall scene. Is there maybe a way of removing this effect from certain objects?