Conventional common wisdom has been that red meat consumption increases the risk of developing heart disease. There are a lot of studies indicating this may be true, but there are also a lot of studies indicating this may not.
A report from the Harvard Health Blog last year discussed this. Not only is there disagreement over what (in red meat) would be the cause, various other foods recognized as healthy also contain significant quantities of the same substances which often take the blame. And in the case of processed red meat (which is unequivocally a negative factor for heart health), the clear connection appears to have more to do with the high salt-content of processed red meats than any naturally occurring substance in the meats itself.
So, is there any modern science which takes into account the likely decrease of other healthier foods in diets with high red meat consumption when evaluating its risk to heart health? As we know, proportion and quantity play just as large a role in the effects of what we eat as what they are made of. For instance, vitamin E and other antioxidants (things which are very healthy) are known to actually promote cancer when over-consumed. Given the conflicting evidence on red meat's role in encouraging heart disease, it seems possible that the real culprit is actually the total diet rather than some specific poison.