"Multivariate MR of iron-related traits on healthspan, parental lifespan, and longevity shows a protective effect for transferrin and a deleterious effect for serum iron."

not in life sciences too, and my interpretation of the above phrase is "if your body iron processing machine works well - good, if not - then bad" which i'd say would be pretty expected, and in general article sounds like there is positive correlation between well working iron related metabolism and longevity which seems not that surprising. They don't seem to address the machinery and nature of that correlation.