Eggs are a major contributor to dietary cholesterol (generally-known fact), so egg intake and dietary-cholesterol intake are strongly positively correlated within these cohorts. The raw egg association (HR 1.06 CVD, 1.08 mortality; O-59) is about the magnitude expected if egg’s effect operated through its cholesterol load. When dietary cholesterol is entered into the model, the egg coefficient attenuates to null (0.99 CVD, 1.03 mortality; O-60) while dietary cholesterol retains a significant, monotonic dose-response (1.17 CVD, 1.18 mortality; O-58). In regression terms, conditioning on the proposed mediator/common driver (dietary cholesterol) removes the egg association — the signature of dietary cholesterol accounting for the egg-outcome link rather than of an independent egg effect, supporting H-26. Caveat: because eggs are the dominant swing component of dietary cholesterol in this population, egg intake and dietary cholesterol are near-collinear, so the model cannot cleanly separate ‘egg-via-cholesterol’ from cholesterol contributed by other foods; residual confounding by overall diet/lifestyle (single-baseline diet in most cohorts) could also inflate the dietary-cholesterol estimate. The attenuation is thus consistent with, but does not prove, dietary cholesterol as the sole operative pathway.
Validity (step 6): approved / checked. Reconstructed step: in a regression, conditioning on X removes the coefficient of a correlated Y when X screens off Y from the outcome; here entering dietary cholesterol nulls the egg coefficient (1.06→0.99, 1.08→1.03) while dietary cholesterol keeps a monotonic dose-response (1.17, 1.18), which is the statistical signature of dietary cholesterol accounting for the egg–outcome link. The decisive undercutting defeater is collinearity-symmetry: with two near-collinear exposures, adjusting for either can null the other regardless of which is causal, so the vanishing alone cannot orient the arrow — and this is exactly the caveat the statement carries. What keeps the step alive as an evidential (not proof) claim is the asymmetry that dietary cholesterol has independent variance from non-egg sources and retains significance while egg does not; that mild asymmetry supports (does not establish) cholesterol-content as operative. Because the conclusion is already stated in the weakened form (“indicates / supporting… does not prove,” with the collinearity and residual-confounding caveats explicit), the inferential step holds as written — no correction needed. Had the statement claimed the adjustment “proves” cholesterol is the exposure, it would have been corrected down to this evidential version; it already is that version.