Many shoppers assume that if they buy a vegetable oil or margarine whole label says "contain no cholesterol" they run no risk of raising their serum cholesterol level. For the record, since cholesterol comes only from animal sources, these two vegetable-based foods never did contain cholesterol. Therefore, the shopper shouldn't be paying attention to the manufacturer's claims about cholesterol. He should be minding whether the product contains a fat called trans fatty acids, and if so, how much. Trans fatty acids are a major contributor to heart disease.