Now margarine is bad for you: "Since butter was fingered as the route to a heart attack in the 1970s, many health-conscious consumers have switched to margarine or, increasingly, one of the low-fat alternatives on the market.... Take the latest breed of spreads that promise to lower levels of low-density lipoprotein, the so-called "bad" cholesterol or LDL, thereby cutting your risk of heart attack. These spreads contain plant sterols, also known as phytosterols, which are naturally occurring parts of all plants and have been shown to lower blood cholesterol levels by an average of 10 per cent. Plant sterols block the body's ability to absorb cholesterol, reducing the level of it in the blood. But as with most good things, there is a hitch. "While they certainly lower LDL cholesterol levels, they deplete the levels of beta carotene and other carotenoids in the body," says nutritionist Rosemary Stanton. Beta carotene is the major source of vitamin A in the western diet and there is growing evidence that carotenoids protect the eyes and have anti-cancer properties"