They certainly won't clog your blood, and are a lot healthier than oils, and generally healthier than most nuts and seds (unless sprouted nuts and seeds). However, there are factions of raw-foodists who warn against having too much - that is, too many - more than one a day - you will end up feeling sluggish and not detoxing as much, and perhaps feeling depressed. But that is a warning about too much fat (even raw fat), not avocadoes per se. Different people can tolerate different amounts of it - I say, enjoy organic avocadoes as much as you wish, and cut back if you feel bogged down in energy, congested, etc. They themselves won't hurt your blood, and are in many ways the healtiest overt fats we can eat.