After years of being told cholesterol is bad for us, we are now told that actually some of it is good. But is food is the main source of our cholesterol?
Cholesterol, a lipid made from mevalonic acid, is in all cells in the body and, along with triglycerides, is used to form cell membranes. The body makes its own cholesterol in the liver and has no need to get any more from food. In fact, cholesterol from the diet generally only makes up a small proportion of the body’s cholesterol.
The good, the bad and the fatty
High density lipoproteins (HDL) carry cholesterol from the arteries to the liver. But low density lipoproteins (LDL) do the opposite: they carry cholesterol from the liver and are oxidised to form plaque deposits on artery walls. Over time these build up, causing narrowing of the arteries and, potentially, heart disease. So the message from the heart is: HDL cholesterol is good; LDL cholesterol is bad.
Functional foods to lower LDL levels
Recently foodstuffs claiming to help lower LDL levels have appeared on supermarket shelves. Predominantly seen in margarine form, these products contain plant sterol esters, long known to reduce LDL levels. The plant sterol esters are modified structurally to form stanol and sterol esters that can then be put into fat-containing foods, like margarine.