However, when sugar and refined starches (such as white flour) replaced saturated fat, the risk of having a heart attack actually increased.
“Most national nutrition guidelines including in the UK, Australia and the US already recognise that swapping out some of the saturated fat in our diet for unsaturated fat is heart-healthy,” says study co-author Peter Clifton, adjunct nutrition professor at the University of South Australia.
“But to this you can add that it's also probably OK to replace some saturated fat-rich food with whole grains, but definitely not OK to swap them with sugar or refined carbohydrates. This could actually be worse than making no reduction to saturated fat at all.
“Unfortunately, when the food industry began creating lower fat versions of foods such as ready meals, puddings and yoghurts, the sugar percentage often went up as a result, which likely wouldn’t have been reducing heart disease risk at all."
It’s also the case that some types of saturated fatty acids that make up saturated fat are less harmful than others. For example, stearic acid, which makes up approximately half of the saturated fats in dark chocolate, does not raise blood cholesterol. (The other saturated fatty acid – palmitic acid – does, though, so best not to eat the whole bar).
Other research indicates that the “food matrix” is important. In cheese and yoghurt, for example, calcium (a mineral that may keep blood pressure normal) could be why these foods have less impact on raising LDL cholesterol than, say, bacon. It could also help explain the observation that consumption of dairy (including full fat dairy) doesn’t appear to be associated with coronary heart disease. (It’s important to take studies like these sceptically, though, since like many nutritional studies, they show correlation, not causation – in other words, people who eat more dairy might simply have healthier lifestyles overall. It’s also important to note that studies focused on dairy have tended to look at milk and yoghurt, but much less on butter or cream).