A controversial nutritional test of a chemically modified fat suggests that the substance is more harmful, in at least some respects, than are the partially hydrogenated vegetable oils that it's intended to replace.
Many food producers are phasing out partially hydrogenated oils, which contain trans fats, substances that have been linked to heart disease. For certain products, such as baker's shortening and margarine, some companies are turning to interesterified fats.
Interesterification shuffles the fatty acids that make up each fat molecule (see "How Interesterification Works," in this week's Food for Thought at Science News Online). Like partial hydrogenation, interesterification produces molecules that seldom or never appear in nature.