Our brains contain cholesterol, too, so it's pretty important!
Jilly60, ask your doctor for a copy of your full lipid profile and discuss it with him. It's not unusual for cholesterol to increase in the early stages of a low-carb diet, but it should have settled after 6 months. How many carbs are you eating daily? If you could give us an idea of your daily diet we might be able to help a bit more.
The following figures are the ones "they" are recommending for diabetics at the moment:
Your total cholesterol level should be below 4.0mmol/l.
LDL levels should be less than 2.0mmol/l.
HDL levels should be 1.0mmol/l or above in men and 1.2mmol/l or above in women.
Triglyceride levels should be 1.7mmol/l or less.
Your Total/HDL ratio should be below 5:1 and preferably around 3.5:1.
The LDLs and triglycerides are the baddies.
My GP doesn't worry about my total cholesterol unless I'm around 6, which I never have been - currently 4.9. He is much more concerned about my Total:HDL ratio, which was 3.1 last time. I personally would not like my Total to be below 4, but what do I know?
Talk things through with your GP. If you didn't have problems with statins previously, a low dose would probably help. If he offers you 40mg, ask if you can go lower!
Let us know how you get on.
Viv 8)