summary - Japanese national cohort (NIPPON DATA80), 5,186 women and 4,077 men aged 30+ at 1980 baseline, 14-year follow-up, egg intake by food-frequency questionnaire (5 categories from “seldom” to “at least 2/day”). Total cholesterol rose monotonically with egg intake, but the mortality relationship was U-shaped rather than linear: in women, both the lowest and highest egg-intake groups had elevated IHD and all-cause mortality relative to the middle categories (~1/day), with the lowest all-cause mortality in the “1/day” and “1 per 2 days” groups.
relevance_note - A general-population Asian result distinct in shape from China Kadoorie’s monotonic protective finding - suggests “more is better” doesn’t generalize even within Asian cohorts, and flags nonlinearity as a modeling choice downstream steps should check.