Low-density-lipoprotein subclasses and response to a low-fat diet in healthy men.
Level 2 - randomized trial
Randomized crossover feeding trial
PubMed 7625363 · doi:10.1093/ajcn/62.2.478S
What was done
In a randomized crossover trial, 105 healthy men consumed a high-fat diet (46% fat) and a low-fat diet (24% fat) for 6 weeks each in random order. Investigators evaluated changes in lipid profiles, apolipoprotein B, and low-density lipoprotein (LDL) subclasses (large buoyant pattern A vs. small dense pattern B) and subfractions across the dietary phases.
What was found
On the high-fat diet, 87 men exhibited pattern A and 18 exhibited pattern B. When switched to the low-fat diet, 36 men converted from pattern A to pattern B, 51 remained stable pattern A, and 18 remained stable pattern B. Compared with the stable pattern A group, the stable pattern B group experienced significantly greater reductions in plasma LDL cholesterol, apolipoprotein B, and mid-sized (LDL II) and small (LDL III) LDL subfraction mass. In the stable A and converter groups, particle mass shifted from larger (LDL I and II) to smaller (LDL III and IV) subfractions with reduced LDL cholesterol but without a reduction in apolipoprotein B. Stable pattern B men also had greater increases in large VLDL subfractions, larger decreases in HDL3, and smaller decreases in HDL2 (exact numerical values and confidence intervals were not reported in the abstract).
Why it matters
These findings show that reducing dietary fat intake can induce a shift toward smaller, denser LDL particles in a substantial portion of individuals and that baseline LDL subclass patterns modulate the magnitude of lipid and apolipoprotein responses to low-fat diets.
Limits
The study included only healthy men, limiting generalizability to women or individuals with dyslipidemia. The abstract does not report exact numerical effect sizes, variance estimates, or p-values. The dietary periods lasted only 6 weeks, leaving long-term adherence, persistence of subclass shifts, and cardiovascular clinical outcomes unmeasured.
Cited by
- supports Switching individuals from a baseline diet to a low-fat, high-carbohydrate diet converts larger LDL particles into smaller LDL particles.