My n=1 experience....The blood donation center I recently began going to gives a total cholesterol count which I realize is pretty useless, but between my first and second donations (roughly 60 days) my total dropped by 61 points. During that time I changed my diet to more of a mediterannean primal / paleo template. I think that had a lot to do with it. I was pleased with the change, but need to retest using the NMR to learn my LDLP.
After I started very low-carb eating (less than 30 g carbs a day) my cholesterol total count shot up to 402. Then I switcher to a higher carb diet (at least 150 g carbs a day) and in 40 days my TC went down to 256. HDL was the same in both tests (about 60), so mostly LDL was the reason for TC rise. Triglycerides were very low in both tests. So my cholesterol dropped 150 points in 40 days.