Ischemic heart disease is a condition characterized by diminished oxygen supply to the myocardium (heart muscle) and chest pain. Ischemic heart disease is also called coronary heart disease. The chest pain from this condition is called angina pectoris. The common cause of cardiac ischemia is impairment of blood flow to the myocardium due to occlusion of a coronary artery. Deprivation of oxygen to the myocardium is the primary cause of the chest pain. This ischemia-induced pain is quite common to various types of muscles but it is more pronounced in the active muscles. It can be life threatening when it occurs in the heart. Angina pectoris can be divided into two basic types: fixed angina (the more common type) and vasospastic angina. Both types of angina can be prevented or reversed with proper nutrition.
Fixed angina is also called stable angina as well as effort angina. The patient with fixed angina usually feels fine at rest. He experiences chest pain when he engages in physical activity. Activities such as walking or going up the stairs would cause chest pain. Impaired oxygen supply to the myocardium occurs because of the narrowing of the coronary arteries. This narrowing of the coronary vessels generally arise from cholesterol deposits in the vascular walls. The occluded segment of a coronary artery then becomes the control point or the resistance region for blood flow. This new control point is proximal to the normal vascular segment that controls blood flow, and it does not respond properly to agents that dilate or constrict the blood vessels.
This type of heart disease can be corrected surgically using bypass surgery to replace the diseased coronary artery. It can also be treated using a stent or angioplasty to keep the diseased coronary segment open; however, therapeutic intervention is more commonly used to manage this condition. Nitroglycerin is the drug of choice for the therapeutic management of effort angina. Nitroglycerin is routinely used because it is a selective dilator of medium-size and diseased arteries. This is important because ischemic heart disease usually affects the large and medium-size coronary arteries. As a reflection of this point, effort angina is often called a disease of the large and medium size coronary vessels.
Potent vasodilators such as nitroproside, adenosine and nifedipine are not effective for treating stable angina. They would produce a condition called coronary steal. Coronary steal exacerbates the angina and the ischemia by further reducing blood flow to the ischemic regions of the heart. When coronary steal phenomenon is present, more blood would flow to the parts of the heart with normal blood vessels (regions of lower resistance) and diminished amounts of blood would trickle through the diseased vascular segments (regions of high resistance).
Vasospastic angina (Prinzmetal's angina or variant angina) is characterized by angina at rest, ie., the chest pain occurs when you are resting. Vasospastic angina contrasts with stable angina where pain is provoked by increased activity. With Vasospastic angina the coronary arteries usually appear normal. They may not have cholesterol deposits or any structural defect that would occlude the coronary vessel or predispose it to occlusion. This seemingly normal coronary vessel would suddenly go into spasm and prevent blood flow to the region of the heart that is vascularized by the occluded artery. This spasm must be relieved within a short time or the patient may suffer a heart attack and may not survive. Fortunately, vasospastic angina is very responsive to treatment with various vasodilators.
Preventing Ischemic Heart Disease Nutritionally
Ischemic heart disease is a condition that can easily be prevented with proper nutrition and changes in life style. Nutritional changes such as avoidance of trans fats and increased consumption of magnesium-rich foods are important spring boards for a healthy cardiovascular system. For example, magnesium is a metabolite that can effectively prevent coronary spasm and certain types of cardiac arrhythmias. L-Arginine, a semi-essential amino acid, is also an important nutrient that supports cardiovascular health.
Low Fat and Low Carb Diets
Low fat and low carb diets are common nutritional protocols for reducing body fat and preventing ischemic heart disease, type 2 diabetes and numerous other chronic diseases. Low fat diets are more commonly used for reversing coronary heart disease (1) but low carb diets (free of trans fats and saturated fats) should be more effective for this task.
The two main advantages of using a low fat diet for removing cholesterol deposits are that low fat diets are generally easier to implement compared to the low carb diets; and it is easier to reduce or eliminate trans fats from the low fat diet. Elimination of trans fats from the diet is crucial in a dietary protocol that supports cardiovascular health. The major weakness of the low fat diet is that the anabolic effects of insulin can remain in full gear, making it difficult to lose body fat and remove cholesterol deposits in the blood vessels. Another weakness of a low fat diet is that it may prevent you from including adequate amount of good oils in your diet. Consequently, you may end up with a diet that has insufficient amounts of good oils such as olive oil, coconut oil and alpha omega 3-rich oils in fish, fruits and nuts.
One key advantage of the low carb diet is that it practically turns you body into a “fat-burning” furnace. With a low carb diet, fat becomes the primary fuel for energy metabolism. Body fat and consumed fats are all aggressively burned in this furnace. A second advantage of the low carb diet is that insulin activity is controlled so that fat storage is prevented or minimized. A third advantage is that you can include adequate amount of good oils in your diet. Good oils are important for maintaining a good cholesterol profile and a healthy cardiovascular system.
The disadvantages and concerns of the low carb diet are numerous. One key disadvantage is that low carb diets are difficult to implement. A second concern for some clinicians is that low carb diets can disturb the bodies electrolyte profile. It lowers the intracellular and extracellular pH (produces acidosis), and presents electrolyte profiles that mimic some unhealthy conditions seen in starvation and certain pathological states. A third weakness is that your ability to engage in high intensity exercise becomes impaired because low carb diet would markedly deplete the glycogen stores in the muscles. Since high intensity exercises are anaerobically supported, glucose from the stored glycogen is needed to support activity during high intensity exercise.
Alpha Omega 3 Fatty Acid and Magnesium-Rich Foods
Diets rich in magnesium and good oils are important for preventing ischemic heart disease. The good oils are the unsaturated fats and the alpha omega three fats. The common sources for these foods are nuts, seeds and sea foods. Examples of such foods are shown below.
One important role of l-arginine in cardiovascular health is that it is the substrate for the synthesis of nitric oxide (2,3). Nitric oxide is the substance that dilates coronary arteries to relieve angina in patients with ischemic heart disease. In the vascular endothelium (a layer of cells that lines the inside walls of the blood vessels) l-arginine is used to produce nitric oxide. A diet rich in l-arginine helps the heart to produce nitric oxide to maintain blood flow in the myocardium. Nitroglycerin, the drug for treating ischemic heart disease, releaves angina by activating the release of nitric oxide.
Preventing Ischemic Heart Disease with Exercise
Exercise is indispensable for achieving and maintaining good health. The beneficial health effects of exercise range from a strong support for cardiovascular health to strengthening of the immune system; and from improving energy metabolism to accelerating wound healing. Endurance and aerobic exercises are particularly beneficial for preventing ischemic heart disease.