Terre is right, a lot of cholesterol is family related and inherited - you might want to talk to your relatives to see if that could be contributing. My mom's is high, as well as my paternal grandma, so I think I might be fighting a bit of an uphill battle
Another thing I didn't think to mention, sorry - the nutritionist that I saw basically said the key was to reduce cholesterol intake (mostly from saturated (animal) fats is where it comes from) combined with increasing fiber. I already did a lot of whole grains, but I'm more careful about my fiber intake now, making sure to hit my daily minimum.