Effect of dietary vegetable and animal proteins on atherothrombosis in mice

Objective It is believed that vegetable and fish, but not animal, proteins prevent thrombosis. The present study compared the effect of long-term intake of purified vegetable and animal proteins (casein, pork, egg white, chicken, white and red fish, soybean, and potato) and powders from whole vegetable and animal meats (soybean, pork, chicken, and horse mackerel) on thrombotic tendency. Methods Western-style high-fat diets with various proteins were given to mice deficient in apolipoprotein-E and low-density lipoprotein receptor for 8 or 12 wk. Thrombotic tendency was assessed by a laser-induced thrombosis test, severity of atherosclerosis was assessed by morphometric analysis of the aortic lesions, and reactivity of platelets was measured by a shear-induced platelet function test. Results There was no difference in thrombotic tendency between the vegetable and animal protein diets with the exception of pork protein, which showed a prothrombotic effect. The latter was not observed in animals kept on a high-protein diet. Thrombotic tendency was not affected by preparation of dietary powders from whole pork, chicken, or horse mackerel meats and casein (control), all of which contained the same percentages of protein and lipid. In contrast, soybean powder showed an antithrombotic effect, which was mainly due to an inhibition of atherogenesis rather than to platelet inhibition. Conclusion Neither the purified animal nor the vegetable protein diet affected thrombotic tendency. Soybean powder inhibited atherothrombosis mainly by inhibiting the atherosclerotic process.