Maybe a sort of interesting study but it's observational and full of speculative mechanistic fluff, and I don't think it controls well enough. We're kinda past the point of egg studies, just study the mechanisms speculated on in an intervention study, right?
> ...adjusting for other dietary factors, demographic variables, lifestyle behaviors, and comorbidities.
They give the data for the specific factors. What is the missing variable which explains their result?
Daily hours of sunlight? Average number of sudoku completions per day?