Forgive me for a long response:

You have posed a very interesting question right on the forefront of the ongoing debate, where competent researchers seem ready to drop the gloves and go at it from opposite sides, each swearing their way is the right way. Like you, I am the average Joe caught in the middle wondering who is right. After a LOT of reading and my own experiences I am coming to the conclusion that both sides may be right, but for different metabolisms.

Anyway, like you I come from a family background of high cholesterol, and like you, I was rigorously semi-vegetarian for years. (Can "rigorous" and "semi" be used in the same phrase?) I mean I ate skinless chicken or salmon once or twice a week, but I rarely ate cheese, never butter, never candy or desserts, never red meat or pork, rarely eggs, rarely mayo. My idea of a hamburger was a whole wheat bun with all the condiments -- but no meat. I bought low-fat cookbooks and was hugely proud of getting through some days with a gram or less of dietary fat.

So why was my cholesterol always high? Mayo Clinic has an "Executive's Checkup" program (for people presumably too busy to see their doctors very often) but it is very comprehensive. A few years ago I had such a checkup and they prescribed me a statin on the spot. (They also said, "Cut down on dietary fat!" but when I told them what I ate they were stumped.) You didn't report what your blood tests showed but I will present mine as a case study. At the time of my checkup:

T. cholesterol 327, triglycerides 168, LDL 229, HDL 64.

On statin: 231, 103, 149, 63. (Far better, but not ideal. )

Here's the interesting part: after reading several books (for example Gary Taubes' "Why We Get Fat") I threw caution to the wind, began eating cheese, steaks, hamburger meat, even butter (the arch-enemy.) Lots of leafy vegetables but no sugar, breads, pastas, etc. Gallons of olive oil, plenty of olive oil mayo. By the way, I continued on the statin.

A few months later: 189, 53, 96, 80. (Absolutely ideal. )

For many people, I suspect, the standard low-fat model works beautifully. But for others, it doesn't: their bodies are quite happy to manufacture blood fats out of innocent-seeming carbohydrates and sugars.

Diane Kress, in "Metabolism Miracle," claims that the latter tendency is a genetic pre-disposition for a subset of the population (I don't recall if she says 45% or 55%). Some start at birth with this metabolism issue, others switch over because of stress, weight gain, aging etc. After that it's a lifelong struggle. She's really talking about the overall metabolic syndrome -- I don't know but perhaps you can have hyperlipidemia and NOT have metabolic syndrome. (I'd say that was true of my mother.) Metabolic syndrome involves hyperlipidemia, but has a lot of additional features: high blood pressure, belly fat, higher blood glucose, etc. It's keyed to a built-in intolerance of carbs which promotes a disturbed insulin system.

The low-carb approach has been shown to work with people with metabolic syndrome. Will it work for someone who does not have signs of metabolic syndrome, and only has hyperlipidemia? Dunno...

Anyway, in this very long and convoluted response to your great question, my advice would be: If a super low-fat diet has not worked for you in terms of getting your cholesterol down, by every means try super low-carb. If it is right for you, you should see the results in a few months.

I hope this is helpful...

I agree with XCcyclist, try the low carb approach. You may even want to exclude certain gluten like rice, corn & wheat as they cause inflammation in your guts that lead to a whole host of other health issues. Also a good probiotic (not Align or other phramacy versions as they don't have enough of the vatious strains of friendly bacteria that's been stripped from taking meds/steroids or antibiotics) from a natural food store can assist you too.

In less than 90 days, my total CHO went from 252, DOWN to 177. My A1c went from 11.2 DOWN to 5.2 - I had a dramatic increase of HDL, and equally in decrease of my LDL. My Triglycerides are down to 102.

This was accomplished with elimination of:
candy
junk food
potatoes
rice
corn
pasta
flour
breads
whole milk
soda

We eat 100% clean at home. All meals are made from scratch and using only fresh foods. You will never find a box of kraft mac & cheese or a lean pocket in my house ever!

So far, I have maintained my current readings for over a year and even improved more (current HDL is 84!). In a couple of weeks I am due for my next blood draw (last draw was June 2012) to see where I am prior to meeting with the Endocrinologist that I also work for...

Familial hypercholesterolemia can be corrected but it requires a total commitment of the person affected with it. They have to be willing to eliminate these types of foods if they want to wipe it off the radar... some of my patients with FH have tried to incorporate whole grains, but it proved to slow down the progress of improving their total CHO panel. Others who did the same thing that I did, showed dramatically fast improvement.

Possibly the most important number that has not been discussed here is fasting blood glucose. That is really the signature of how your body is handling carbs.

According to MedOnline and "Metabolism Miracle" (by Diane Kress) if your fasting blood glucose is over 90 you have carbohydrate intolerance -- and insulin resistance. (MedOnline says frankly that over 89 your pancreas is possibly damaged already -- that was a shocker to me.)

Diabetes (when your pancreas burns out on insulin production for good) is universally recognized at 125 fasting blood glucose. But pre-diabetes (that is to say, diabetes in early stages) begins at 100. (Some say at 90 -- others at 110.)

The important thing is that before you get to the 125 threshold there is arguably the possibility you can slow, halt and even reverse the progression. A strict low-carb regimen appears to be one of the leading -- possibly the very best leading -- ways to do that.