Butter is a natural product. Vegetable, olive, sunflower, rapeseed oils etc are also natural products. However, when those vegetable fats and oils are converted into
spreadable products, then they are not so good-they have been hydrogenated, and even if it is made with plant sterols is still hydrogenated fat. Looking up hydrogenated fats produces this-
"Hydrogenation is the process that turns liquid oil into a more solid fat. Liquid oils are ‘hardened’ by adding hydrogen to stabilise the fat, making it easier to use in recipes for biscuits, cakes, pastry, and other processed foods.
You can tell how ‘saturated’ a fat is by its texture at room temperature. Saturated fats like lard, fat on meat and cheese are solid at room temperature, whereas unsaturated fats - such as vegetable oils - are liquid at room temperature. As an unsaturated oil is gradually more hydrogenated, the inserted hydrogen atoms make it firmer and more solid at room temperature.
Usually, the hydrogen slips naturally into the fat at the point where there is a gap (called an ‘unsaturated bond’) in the fat structure. The position it takes up is called the ‘cis��� position, which occurs naturally in nature as well.
Sometimes the hydrogen slips into the gap in a different position, altering the overall shape of the final fat. The ‘trans’ position of the inserted hydrogen alters the overall shape of the fat, making it difficult for our body to process. Foods containing hydrogenated vegetable oil (always declared in the ingredients list) may therefore also contain
trans fats.
Trans fats found in food have no known nutritional benefit and appear to be harmful. They increase blood
cholesterol levels and independently increase the
risk of heart disease. Some evidence suggests that the effects of these trans fats may be worse than saturated fats.
So, as part of a healthy diet we should try to reduce the amount of foods we eat that contain hydrogenated or saturated fats and replace them with unsaturated fats.
Foods that are rich in unsaturated fats include oily fish, avocados, nuts and sunflower, rapeseed and olive oils.
Trans fats are also naturally found at very low levels in foods such as
dairyproducts, beef and lamb. However, the type of trans fat found in dairy products (such as milk, cheese and cream) is different to other types of trans fat and are not considered harmful to health".
So, although I use rapeseed oil and olive oil in dressings and cooking, I use butter too. I'd rather have a little of the real thing than a lot of something made up!