There has been a sort of craze recently about studies proving that saturated fat is not bad for your heart, as was previously thought (and taught). This seems to be true; studies examining the rather theoretical assumption that saturated fat causes heart disease have been inconclusive for many years.
Mainstream media and even some health care providers seem to make of it that saturated fat suddenly became healthy. This is, of course, nonsense. First of all:
Therefore, merely replacing some of the saturated fat in your diet by unsaturated fat leads to several important health benefits. And last but not least, most foods that contain saturated fat are unhealthy for many other reasons. There is an overwhelming amount of evidence that:
On the other hand, there doesn’t seem to be anything wrong with a moderate intake of butter (which also consists of saturated fat), and, in fact, studies have shown that:
So if the choice is between a margarine high in trans fat and butter, definitely go for butter. Nonetheless, margarines low in trans fat (containing less than 0.5% of trans fat) and high in polyunsaturated fat should pose no health risk and even provide some health benefits.