Change in dietary saturated fat intake is correlated with change in mass of large low-density-lipoprotein particles in men.
Level 2 - randomized trial
Randomized crossover trial
PubMed 9583838 · doi:10.1093/ajcn/67.5.828
What was done
A total of 103 men were randomly assigned to a low-fat (24% fat) and a high-fat (46% fat) diet for 6 weeks each in a crossover design. Nutrient intakes were estimated from 4-day diet records and analyzed for associations with plasma lipoprotein subclasses measured by analytic ultracentrifugation. In a subset of 43 men, postheparin plasma lipoprotein lipase and hepatic lipase activities were also measured.
What was found
Increases in intake of total saturated fatty acids, myristic acid (14:0), and palmitic acid (16:0) were positively correlated with increases in the mass of large LDL particles (flotation rate Sf 7-12; P < 0.01), LDL peak particle diameter, and flotation rate, but not with changes in total LDL-cholesterol concentration. Changes in saturated fatty acids, myristic acid, and palmitic acid were also inversely associated with changes in hepatic lipase activity (P < 0.05). On the high-fat diet alone, dietary saturated fat intake inversely correlated with small, dense LDL of Sf 0-5 (P < 0.01), driven specifically by myristic acid (P < 0.001). Stearic acid (18:0), monounsaturates, and polyunsaturates showed no significant associations. Exact numerical effect sizes and correlation coefficients were not reported in the abstract.
Why it matters
This study shows that dietary saturated fat intake predominantly increases larger, cholesterol-enriched LDL particles rather than small dense LDL, a shift linked mechanistically to reduced hepatic lipase activity.
Limits
The study was conducted entirely in men, limiting generalizability to women. Dietary intake was self-reported via 4-day records rather than strictly controlled through provided feeding. Lipase activity was measured in only a subset (n = 43), and correlation coefficients or absolute changes were not provided in the abstract.
Cited by
- supports Saturated fat intake increases large LDL particles rather than small, dense LDL particles in the majority of the population.