2. Margarine was originally recommended for people at risk from coronary heart disease on the grounds that saturated fats in butter were worse for the heart than polyunsaturates in soft margarines. But there are two sorts of polyunsaturates, Omega 3 and Omega 6. The diet of early humans was rich in Omega 3, which comes from wild animals, some plants, vegetable oils such as rapeseed and linseed, and some oily fish. It increases the amount of "good" cholesterol (HDL) and cuts hypertension. Omega 6, however, increases blood clotting, "bad" cholesterol (LDL) levels and the rate at which weight is gained. It comes from grain, domestic animal meat and oils such as safflower and sunflower. It is a major ingredient in margarine, which also contain transfatty acids which rarely occur in nature and have been linked with heart disease and smaller babies.
3. A 1995 British survey of cholesterol studies showed that the American goal of a 30% fat diet does not affect heart disease rates, and has little effect on cholesterol levels.