The Nation's Health + [Small LDL]

The disastrous results of a low-fat diet

Rob was never that committed to following the program in the first place.

I met Rob because of a modest heart scan score and consultation for a cholesterol abnormality. Rob had been cycled through all the statin agents by his primary care physician, all of which resulted in terrible muscle aches that he found intolerable.

I started out, as usual, characterizing his cholesterol abnormality with lipoprotein testing (NMR):

LDL particle number 1489 nmol/L
LDL cholesterol (Friedewald calculation) 143 mg/dl
Small LDL 52% of total LDL
HDL 50 mg/dl
Triglycerides 82 mg/dl

(LDL particle number is the emerging gold standard for LDL quantification, superior to calculated or Friedewald LDL cholesterol for prediction of cardiovascular events.)

Rob is a busy guy. After only a couple of brief visits, life and work got in the way and Rob let his attentions drift away from heart health. Since the information I provided made little impact on his thinking, he reverted to the low-fat diet his primary care doctor had originally prescribed and that he read about in magazines and food packages. He also ran out of the basic supplements I had advised, including fish oil and vitamin D, and just never restarted them.

A couple of years passed and Rob decided that just poking around on his own might not cut it. So he came back to the office. We repeated his NMR lipoprotein analysis:

LDL particle number 2699 nmol/L
LDL cholesterol (Friedewald calculation) 229 mg/dl
Small LDL 81% of total LDL
HDL 53 mg/dl
Triglycerides 78 mg/dl

Two years of a low-fat diet had caused Rob's LDL particle number to skyrocket by 81% , nearly all due to an explosion of small LDL. Recall that small LDL is more susceptible to oxidation, more inflammation-provoking, more adhesive--the form of LDL particles most likely to cause heart disease.

Also, note that, despite the enormous increase in small LDL, HDL and triglycerides remained favorable. This counters the popular rule-of-thumb offered by some that small LDL is not present when HDL is "normal."

Low-fat diets as commonly practiced are enormously destructive. In Rob's case, a low-fat diet caused both calculated Friedewald LDL as well as LDL particle number to increase dramatically. In many other people, low-fat diets increase calculated Friedewald LDL modestly or not at all, but cause the more accurate LDL particle number to increase significantly, all due to small LDL.

I'm happy to say that, once Rob witnessed how far wrong he could go on the wrong program, he's back on Track. (Sorry, pun intended.) He has resumed his supplements and eliminated the food triggers of small LDL--wheat, cornstarch, and sugars.