Atherosclerosis is the progressive formation of plaque on the lining of arteries, leading to narrowing and eventually obstruction. There are many theories as to the cause, though we do know that hypertension, high cholesterol, diabetes, smoking, and lack of physical activity accelerate the process. Injury to the cells that line the inside of the artery (endothelium) is the initial event, at least partially due to hypertension and increased stress as the vessel is chronically dilated. Once injured, further damage is propagated by low density lipoprotein (LDL) cholesterol, homocysteine, free radicals, and nicotine. White blood cells and platelets attempt to repair the damage, but become adherant to the damaged area, releasing growth factors and other substances that result in thickening of the muscular lining of the artery and the formation of fibrous tissue. As this process continues, the fibrous plaque grows, further weaking the artery and leading to eventual symptoms as the blockage reaches 90%. Angina symptoms occur when blood flow through the coronary (around the heart) arteries is compromised (ischemia). As the plaque grows, the flow of blood is disturbed, allowing the formation of blood clots around the plaque. A heart attack is usually due to clots coming loose and migrating downstream, totally occluding a portion of the artery, resulting in the complete obstruction of blood flow to a portion of the heart muscle (infarction). A stroke is usually the result of plaque fragments breaking off or gradual occlusion.
Prevention is the best medicine, especially with atherosclerosis. The major risk factors are well identified. Other risk factors include:
Decreased antioxidants
Low levels of essential fatty acids
Low levels of magnesium and potassium
Increased platelet stickness (platelet aggregation)
Increased fibrinogen formation
Elevated levels of homocysteine
Alternative approaches and conventional medicine boundaries blur when it comes to the treatment of atheroscerosis, as research further identifies the causes, verifying the treatments that have been previously suggested and considered to be alternative.
Smokers have 3 to 5 times the risk of coronary heart disease as non-smokers. The chemicals from smoke are carried directly to the plaque by LDL cholesterol and also damage the LDL cholesterol. Both mechanisms result in damage to the arterial lining directly. Smoking also has the effect of promoting platlet aggretation and increasing fibrinogen levels, as well as indirectly contributing to elevated cholesterol levels. Smoking is a source of free radicals, which play a major role in not only atherosclerosis, but cancer and aging as well. Smoking cessation is critical to the prevention of atherolsclerosis. If you smoke, or have ever smoked, it is even more important to ensure an adequate intake of antioxidants.
Elevated Cholesterol (Hyperlipidemia):
Very low density lipoprotein (VLDL) cholesterol and LDL cholesterol carry cholesterol and triglycerides from the liver to the cells of the body, thus elevations of either are associated with an increase risk of developing atherosclerosis. High density lipoprotein (HDL) cholesterol carries cholesterol and triglycerides from the cells of the body back to the liver to be excreted from the body. The higher the HDL cholesterol levels the lower the risk of developing atherosclerosis. Controlling cholesterol levels and altering the lipid profile in favor of HDL cholesterol through diet, exercise, natural treatments, and conventional medicine is essential to halting and even reversing the progression of atherosclerosis. See the section on hyperlipidemia for more.
Elevated Blood Pressure (Hypertension):
As stated earlier, hypertension can result in initial damage to the endothelium, an inciting event in the formation of a fibrous plaque and subquently the developement of atherosclerosis. Controlling blood pressure is a basic tennet in the prevention of atherosclerosis. See the section on hypertension for more.
Diabetics have 2 to 3 times the risk of dying from atherosclerosis as compared to a non-diabetic. Diabetics must keep their blood pressure lower (less than 135/80) than the normal standard (less than 140/90). Diabetics also routinely have lower levels of many of the antioxidants, futher increasing their risk of developing atherosclerosis. To help prevent atherosclerosis, diabetics must maintain tight control of their blood glucose levels, and be sure to supplement their diet with adequate intake of antioxidants. See the section on diabetes for more.
Regular exercise decreases total and LDL cholesterol levels, increases HDL cholesterol levels, inceases the metabolism of glucose, improves the functional capacity of the cardiovascular system, reduces blood pressure, and reduces obesity. All of which are key to the prevention of atherosclerosis. A bare minimum of 15 to 20 minutes of exercise at your training heart rate three times per week is necessary to obtain cardiovascular benefit. Ideally, exercise should be part of your daily routine. Aerobic activities such as walking (fast), runnining, bicycling, swimming, aerobics, and racquet sports are good examples. If you currently lead a sedentary lifestyle, consult your care provider prior to starting an exercise program.
It is now commonly accepted that free radicals (pro-oxidants) play a major role in the development of atherosclerosis, as well as cancer and aging. The body is capable of manufacturing antioxidants that can neutralize the effects of free radicals. However our bodies are bombarded with free radicals from such sources as cigarette smoke and preservatives. Cholesterol and triglycerides are particularly prone to free radical damage, further promoting atherosclerosis. Antioxidant (vitamins A, E, and C) supplementation is critical, especially if you smoke or have ever smoked, or if you have diabetes.
Low levels of essential fatty acids:
Studies demonstrate the diets rich in omega-3 fatty acids (FA) from fish or vegetable sources are associated with a decreased risk of developing coronary heart disease. Sources include: cold water fish (salmon,trout, tuna) - 2 to 3 times per week. Also, sardines, herring, anchovies, flaxseed oil, walnuts, romaine lettuce, mesclun mixed greens, argula, kale, collard greens, swiss chard. Use olive oil instead of other cooking oils, it is high in omega-3 FA and low in omega-6 FA.
Low levels of magnesium and potassium:
Magnesium and potassium are essential minerals for the proper function of the heart. The average highly refined american diet is strikingly low in these minerals, as well as having a dangerously low potassium to sodium ratio. Low magnesium levels have been well documented to be associated with heart attack. The blood levels of magnesium and potassium are routinely checked during a work-up for suspected heart attack and if low is supplemented either orally or intravenously. Some of the beneficial effects of magnesium are: its ability to improve energy production in the heart, dilate coronary arteries which improve blood flow to the heart, reduction of peripheral resistance which decreases blood pressure and reduces the demand on the heart, and inhibition of platelet aggregation which potentially decreases the size of the infarct (during a heart attack), and stabilization of the rate and rhythm of the heart. Potassium is further discussed in the section on hypertension.
Increased platelet stickness (platelet aggregation):
When platelets adhere to eachother (aggregate) they release compounds that promote the formation of the atherosclerotic plaque. They can also form clots independent of the plaque, additionally increasing the risk of heart attack or stroke. This is the concept behind the recommendation for the use of aspirin (an antiplatelet) for the prevention of heart attack and stroke. Saturated fats and cholesterol increase platelet aggregation, omega-3 FA decrease platelet aggregation. Garlic has also been demonstrated to inhibit platelet aggregation.
Increased fibrinogen formation:
Fibrinogen promotes atherosclerosis through several mechanisms. Elevated levels of fibrinogen are associated with an increased risk cardiovascular disease. Exercise, niacin, omega-3 FA, and garlic promote the break-down (fibrinolysis) of fibrinogen.
Elevated levels of homocysteine:
Elevation levels of homocysteine are associated with an increase risk of heart attack, stroke, and peripheral vascular disease. Homocysteine is thought to promote atherosclerosis by damaging the arterial wall, reducing its integrity as well as by interfering with the formation of collagen. A deficiency in folic acid, vitamin B6 or vitamin B12 can result in elevevated levels of homocysteine. Dietary supplementation of folic acid as well as vitamins B6 and B12 can lower homocysteine levels.
A diet low in refined carbohydrates, high in antioxidants, high in essential fatty acids (omega-3), high in fiber, and adequate in specific minerals is essential to the prevention and reversal of atherosclerosis.
Brief recommendations:
Consume more dietary fiber (vegetables and fruits, or psyllium)
Limit refined carbohydrates.
Eat foods as natural and unprocessed as possible.
Eat non-starchy vegetables.
Eat less natural carbohydrate-dense foods.
Do not drink soft drinks, fruit juices or alcohol.
Use olive oil only, not regular vegetable oils.
Eat more omega 3 FA whenever possible.
Avoid trans-fatty acids.
For more information, see the expanded section on dietary recommendations.
Vitamin E is a fat soluble antioxidant, able to be incorporated into
LDL cholesterol and prevent free radical damage at that level. It is
the most studied antioxidant, for which there is the most evidence of
its effectiveness. Studies indicate that therapeutic doses of vitamin
E result in a significant reduction in nonfatal heart attacks. There
is evidence that vitamin E can also help to prevent atherosclerosis.
There appears to be a synergistic effect with the addition of vitamin
C, resulting in an even greater risk reduction.
Sources: Polyunsaturated vegetable oils, seeds, nuts, whole grains
Dose: 400 to 800 IU daily (look for mixed tocopherols)
Safety issues: Vitamin E has a blood thinning effect, and as
such should be used with care in the presence of other blood thinning
medications or garlic.
Vitamin C is a water soluble antioxidant. As stated above, vitamin C
with vitamin E can lower the risk of atherosclerosis better than
either vitamin alone. Vitamin C also strengthens collagen in arterial walls.
Sources: Red chili peppers, sweet peppers, kale, parsley,
collard greens, turnip greens, broccoli, brussel sprouts, watercress,
cauliflower, cabbage, strawberries, citrus.
Dose: 500 to 1000 mg daily, divided at doses greater than 500 mg.
Several studies show a decreased risk of atherosclerosis with a diet
high in beta-carotene. These findings have not been duplicated
with supplemental forms of beta-carotene.
Sources: Dark green and orange-yellow vegetables: carrots,
sweet potatoes, squash, spinach, romaine lettuce, broccoli, apricots,
and green peppers.
Dose: 3 mg daily (5000 IU) from a dietary source.
Folic acid decreases the levels of homocysteine in the blood.
Elevated levels of homocysteine is recognized as a risk factor for
coronary heart disease. Most sources recommend that for heart disease
prevention, folic acid should be taken with vitamins B6 and B12.
Sources: Dark green leafy vegetables, oranges, rice, brewer's
yeast, beef liver, beans, asparagus, soybeans, soy flour.
Dose: 400 mcg, taken with vitamins B6 and B12
Adequate intake of vitamin B6 can reduce the risk of coronary heart
disease. It can reduce the levels of homocysteine as well, especially
when combined with folic acid and vitamin B12.
Sources: Nutritional (torula) yeast, brewer's yeast, sunflower
seeds, wheat germ, soybeans, walnuts, lentils, lima beans, buckwheat
flour, bananas, and avocados.
Dose: Up to 50 mg daily. Best in the form of B-complex supplement.
Vitamin B12 works with folic acid and vitamin
B6 to decrease blood levels of homocysteine, which is associated
with an increased risk of coronary heart disease.
Sources: Beef, liver, clams, lamb - all contain 80 to 100 mcg
of B12 per 3.5 ounce serving. Sardines, chicken liver, beef kidney,
calf liver - all contain 25 to 60 mcg per serving. Trout, salmon,
tuna, eggs, whey and many cheeses contain at least the RDA (>2
mcg) per serving. It is also found in sea vegetables such as dulse,
kelp, kombu and nori, as well as soy products. Vegetarians may need
to take supplemental forms of vitamin B12 because most sources are
from animal products.
Dose: In the absence of pernicious anemia, the RDA of 2 mcg
per day is sufficient, best in the form of B-complex supplement (if
not a food source).
Coenzyme Q10 is an antioxidant, helping to improve tissue oxygenation.
Sources: Found in small amounts in nature. Necessary amounts
need to be supplemented.
Dose: 30 - 300 mg daily, divided into two to three doses.
Better absorbed when taken in an oil-based gel form.
Atherosclerosis is a preventable, slowly progressive process, accelerated by hypertension, high cholesterol, diabetes, smoking, and lack of physical activity.
Well documented risk factors include:
Smoking. high cholesterol, high blood pressure, diabetes, HDL < 35, family history of early CHD, male age 45 and older, female age 55 and older or menopause without HRT, decreased antioxidants, low levels of essential fatty acids, low levels of magnesium and potassium, increased platelet stickness, increased fibrinogen formation, and elevated levels of homocysteine.
A diet low in refined carbohydrates, high in antioxidants, high in essential fatty acids (omega-3), high in fiber, and adequate in specific minerals is essential to the prevention and reversal of atherosclerosis.
Vitamin E: 400 to 800 IU daily (look for
mixed tocopherols)
Vitamin C: 500 to 1000 mg daily, divided
at doses greater than 500 mg
Beta carotene: 3 mg daily (5000 IU)
from a dietary source
Folic Acid: 400 mcg, taken with vitamins
B6 and B12
Vitamin B6: Up to 50 mg daily (in the
form of B-complex supplement)
Vitamin B12: 2 mcg per day (in the
form of B-complex supplement)
Coenzyme Q10: 30 - 300 mg daily, divided
into two to three doses