The following random thoughts are just that - my thoughts, not facts. However, I have provided some selected cites for most of them. If you think I have been a little selective, I agree - I'm human and will spin things my way. So I've also given links to some medical search engines at the foot if you would like to do some further reading. Just one rule: papers funded by pharmaceutical companies, especially statin manufacturers, or written by authors with links to those companies have little credibility with me.
The cites are only representative of a lot of general reading. There are many more supporting papers out there. I am happy to hear from anyone with more specific papers on particular aspects - pro or con.
These thoughts are based on my own reading from many various sources over time. Lately I have found them reinforced in Taubes' book "Good Calories, Bad Calories", but most I had read before that from other sources.
1. Eating excessive carbohydrates leads to high triglycerides. The definition of "excessive" may depend on whether or not the diner has diabetes. Triglycerides are one of the three major reported components of the usual lipids panel, the other two being HDL and LDL. One that we should get but often don't is VLDL, the dangerous one; usually that is estimated by dividing the triglycerides by 5 (in mg/dl). But that estimate is very approximate.
2. LDL is considered by the mainstream medical establishment to be the bad cholesterol and most anti-cholesterol meds target that. But high triglycerides, high VLDL and low HDL are actually the ones we should be most concerned about.
3. The absolute number of our LDL is less important than the specific number of certain components of LDL; the dangerous ones are the small, dense particles. High triglycerides usually indicate high proportions of those small dense particles. Better indicators of our lipids health are VLDL and the apolipoproteins A1 and B.
4. ALL of the foods we eat affect our cholesterol levels. EXCESS of carbohydrates OR fats may lead to dyslipidemia.
5. The past research on the relationship between cholesterol and heart disease is misleading at best. There appears to be shaky support for the hypothesis that lowering cholesterol, particularly LDL, improves overall mortality and even less support for the use of statins to do that.
6. Inadequate dietary fat will lead to low HDL.
7. Exercise usually, but not always, helps increase HDL.
8. A low HDL is a better indicator of future cardiac problems than high LDL and apolipoprotein levels are a better predictor than either.
9. Diabetics should aim for a triglycerides to HDL ratio of less than 3.0 in mg/dl or 1.3 in mmol/l.
10. Cholesterol in the foods we eat such as eggs and seafood has an insignificant effect on the cholesterol in our blood stream.
11. Low LDL is also dangerous and can be related to other problems such as Parkinson's Disease, cancer and other causes of early death.
12. There is growing concern that the over-prescription of statins and limited but alarming research into their side effects needs a lot more investigation.
Putting that all together, I no longer worry about the level of fats in my diet for their affect on cholesterol. I am selective in my choices of oils, but for other reasons such as Omega 3 content or eliminating trans-fats. I also found that reducing carbohydrates reduced my triglycerides as well as my blood glucose levels. I also dropped my statin, lipitor, four years ago.
When you look back through that list, some things stand out to me. If I am going to worry about cholesterol at all, the two things that will improve it most are moderating carbohydrates for better triglycerides and increasing exercise for better HDL. It seems a happy coincidence that those are the same two things that improve my blood glucose levels most. Additionally, inclusion of some additional fats in my menu to replace those carbohydrates may also help increase HDL.
For those interested in further reading to support - or refute - my thoughts here are a few useful search engines: Google Advanced Scholar, Medline and Highwire.
Cheers, Alan
Everything in Moderation - Except Laughter.
Footnote:
Here are some additional references for you in no particular order. Most of these papers and articles apply to more than one of the points above, which is why I found it awkward to include them in the body. The titles tend to give the context.
Effects of a low-fat, high-carbohydrate diet on VLDL-triglyceride assembly, production, and clearance
Effect of Dietary Carbohydrate on Triglyceride Metabolism in Humans
Effects of a low-fat, high-carbohydrate diet on VLDL-triglyceride assembly, production, and clearance
Increased consumption of refined carbohydrates and the epidemic of type 2 diabetes in the United States: an ecologic assessmentEffect of the Magnitude of Lipid Lowering on Risk of Elevated Liver Enzymes, Rhabdomyolysis, and Cancer
Exercise Prevents the Accumulation of Triglyceride-Rich Lipoproteins and Their Remnants Seen When Changing to a High-Carbohydrate Diet
Effects of Protein, Monounsaturated Fat, and Carbohydrate Intake on Blood Pressure and Serum Lipids
Carbohydrate-Induced Hypertriglyceridemia: An Insight into the Link between Plasma Insulin and Triglyceride Concentrations
A Low-Carbohydrate, Ketogenic Diet versus a Low-Fat Diet To Treat Obesity and Hyperlipidemia
Plasma high density lipoproteins HDL2, HDL3 and postheparin plasma lipases in relation to parameters of physical fitness.