Cattle raised on 10% flax have much more omega-3 fatty acids in muscle compared to those fed corn. We tested whether there were any health benefits to this increased level of omega-3 fatty acids by feeding diets composed of rib eye steaks from corn fed or 10% flax fed cattle in male rats. Sprague-Dawley rats at 3 weeks of age were fed one of two diets, with an n of 10 in each group. The contained 10% fat from the cooked rib eye steaks, using a modification of the AIN-77 diet, for a 5 week period. Total serum cholesterol was markedly reduced in the rats fed flax fed beef compared to the corn fed beef. Serum vascular cell adhesion molecule-1 (VCAM-1) levels were significantly reduced in rats from the flax fed group, but C-reactive protein and intracellular adhesion molecule-1 (ICAM-1) levels did not differ. The changes corresponded to increased levels of docohexanoic acid in the membrane phospholipids of flax fed rat hearts and liver and decreased arachidonic acid levels in the hearts. The changes in fatty acid composition of the phospholipid fraction demonstrated that feeding beef from cattle fed flax can alter the fatty acid composition of membrane phospholipids favorably and at the same time lower blood cholesterol and vasoactive adhesion molecules implicated in platelet aggregation. A human study is warranted on the basis of these findings to determine if feeding practices of livestock such as cattle can lead to a more healthy food product. Supported by the National Cattlemen's Beef Association