Small, dense LDL is the type of cholesterol that gets under your vascular "skin", the thin lining that protects the inside of the vessel wall. These small, dense molecules are suspected to cause the first insult, which invites other factors to pile on and build a dangerous sludge in your artery called atherosclerosis. If you are a baby boomer like me, you were taught that cholesterol was bad. Then, no, no, HDL cholesterol is actually good; it was LDL cholesterol that was bad. Now we learn there are two types of LDL, large, buoyant LDL and the small, dense LDL. The small, dense version is the worst of the two.
We also learned that the main cause of elevated cholesterol was fat. Well, yes, factory-made transfat is bad, but the biggest dietary cause of increased small dense LDL, is... carbohydrates! Dr. William Davis, author of The Heart Scan Blog, illustrates this in the case of Joseph, "a whip-smart corporate attorney" with high LDL cholesterol. Joseph's numbers before changing his diet were: LDL -2620 nmol/L, and small LDL - 2331 nmol/L. Dr. Davis writes:
I advised him to eliminate wheat, cornstarch, and sugars, while limiting other carbohydrate sources, as well. Joseph didn't like this idea very much … (he) replaced all sugar and refined flour products with whole grains, but did not restrict his intake of grains.
LDL decreased a small amount to 2451 nmol/L and small LDL to 1998 nmol/L. Dr. Davis:
I explained to Joseph that any grain, complex, refined, or simple--will, just like other sugars and carbohydrates, still provoke small LDL. Given the severity of his patterns, I suggested trying again, this time with full elimination of grains.
Finally, LDL significantly decreased to 1320 nmol/L and small LDL to 646 nmol/L
This is typical of the LDL responses I see with elimination of wheat products on the background of an overall carbohydrate restriction.
Take home point: Although genetics plays a role, the modern high carb diet with its refined sugars and grains raises your small, dense LDL, the really bad cholesterol. Unfortunately the test for small, dense LDL is expensive and not available in most medical offices. Talk to your doctor and find out what evaluation is right for you.
(By the way, statin medications do not decrease small, dense LDL.)