We have come to recognise that saturated fatty acids, as they are found, in particular, in meat, butter, coconut oil, etc., are hardly recommendable.
It is less well-known that there are also distinct differences between the unsaturated fatty acids.
In many processes, the substances formed by omega-3 fatty acids act as adversaries to omega-6 fatty acids. An excess of omega-6 fatty acids affects various diseases negatively. Thus, it depends on the ratio of omega-6 fatty acids to omega-3 fatty acids. Most foods, particularly (pork) meat, though even sunflower oil, etc. as well, contain significantly more omega-6 fatty acids, while large amounts of omega-3 fatty acids are only present in few foods, such as fatty cold-water fish, linseed and walnut oil. Accordingly, most humans have a relative deficiency of omega-3 fatty acids.