Diet and New Lesions of the Coronary Arteries

To the Editor.—  In a recent issue of JAMA, Dr Blankenhorn et al¹ reported that increased intake of lauric, oleic, and linoleic acids significantly increased the risk of new atherosclerotic lesions over a 2-year period. The authors concluded that "protein and carbohydrates are preferred substitutes for fat calories, rather than monounsaturated or polyunsaturated fat."This is indeed a very important study, but the dietary data require further analysis to determine the intake of ω-3 fatty acids and the ratio of ω-6 to ω-3 fatty acids, in view of the finding that linoleic acid (an ω-6 fatty acid found in vegetable oils) significantly increased the risk of new atherosclerotic lesions. This, of course, is not entirely unexpected. Linoleic acid is metabolized to arachidonic acid, whose metabolites—prostaglandins, thromboxanes, and leukotrienes of the 2-series—have proaggregatory effects on platelets and promote thrombosis and chemotaxis of monocytes/macrophages, which contributes to the initial development