40 normolipidemic men, randomized crossover: egg diet (3 eggs/d, 640 mg/d additional dietary cholesterol) vs. placebo (0 mg/d), 30 days each with a 3-week washout. Hyporesponders (classified by total-cholesterol change per 100 mg dietary cholesterol) showed no significant rise in LDL-C or HDL-C on the egg diet; hyperresponders showed significant rises in both. Hyperresponders also had higher LCAT and CETP activity during the egg period, indicating increased reverse-cholesterol-transport flux. The LDL:HDL ratio was not adversely changed in either group.
relevance_note: Direct measurement that hyperresponders’ extra cholesterol raises LDL and HDL together without worsening the LDL:HDL ratio — tempers a naive “hyperresponder = pure harm” reading.