Heart Bars, a new designer food, are supplemented with a fairly large amount of L-Arginine (Arg), a nitrogen-rich amino acid that serves as the natural precursor to nitric oxide (NO) in endothelial cells. NO is also known as endothelial derived relaxing factor (EDRF or EDNO). The release of NO from endothelial cells causes the blood vessels to relax and this increases blood flow. NO reduces the tendency of platelets and macrophages to adhere to the blood vessel wall and inhibits the proliferation of smooth muscle cells. This can slow the progression of atherosclerosis and reduce the tendency for blood clots to form.Nitroglycerine is a drug that also simulates the production of NO. Nitroglycerine tablets can quickly relieve angina by relaxing constricted coronary arteries. The effects of Arg on dilating coronary arteries are not as quick and dramatic as those of nitroglycerine, but they are longer lasting. Research has shown that an extra 6-9 grams of Arg daily improves vascular function.The average American diet supplies about 5-6 grams of Arg, but this may not be enough, particularly for individuals with advanced atherosclerosis. Unfortunately, most of the Arg in the American diet comes from meats and dairy products with their high saturated fat and cholesterol content, which increase LDL-C. A high level of LDL-C damages the endothelial cells and reduces their ability to produce NO from Arg. In addition, high levels of dietary L-methionine (Met) increase the production of homocysteine (Hcy). Higher levels of Hcy have been shown to promote atherosclerosis and impair endothelial cell function by destroying NO. Soy products, beans, nuts and seeds are all low in Met but are a good source of Arg, low in saturated fat and contain no cholesterol. They contain fiber and plant sterols, which actively lower LDL-C. These foods, along with fruits, vegetables and whole grains, are also good sources of antioxidant nutrients and phytochemicals, which help protect the artery’s endothelial cells from the damaging effects of excess Hcy and LDL-C. By contrast, a diet high in fat and sugar has been shown to impair endothelial cell function and reduce vasodilatation of blood vessels in animals. Constricted blood vessels in these animals resulted in a higher blood pressure, compared to a high complex carbohydrate diet. A more vegetarian diet rich in fruits, vegetables, whole grains and beans is far preferable to the typical American diet.