Atherosclerosis

Cerebrovascular disease is caused by plaque buildup in the arteries that supply the brain with oxygen-rich blood. Cerebrovascular disease causes transient ischemic attack (a sudden loss of brain function with complete recovery within 24 hours) and stroke.

Symptoms may include:

• Weakness or paralysis on one side of the body
• Garbled speech and/or inability to comprehend speech
• Loss of vision in one eye
• Paralysis of facial muscles
• Muscle weakness
• Impaired senses
• Stupor
• Poor coordination
• Involuntary, jerky movements on one side of the body
• Rapid, repetitious, involuntary eye movement
• Vertigo

Peripheral artery disease is caused by plaque buildup in the arteries that supply the extremities of the body (such as the hands and feet) with oxygen-rich blood.

Symptoms may include:

• Pain, aching, cramps, numbness or sense of fatigue in the muscles of the lower extremities
• Diminished pulses in the extremities
• Decreased muscle mass
• "Bruits" (blowing sounds that the physician hears with a stethoscope that indicates turbulence in blood flow)
• Hair loss
• Thickened nails
• Smooth, shiny skin surface
• Skin that is cold to the touch
• Gangrene

The most important dietary changes in protecting arteries from atherosclerosis include avoiding meat and dairy fat and avoiding foods that contain trans fatty acids (margarine, some vegetable oils, and many processed foods containing vegetable oils). Increasingly, the importance of avoiding trans fatty acids is being accepted by the scientific community. Leading researchers have recently begun to view the evidence linking trans fatty acids to markers for cardiovascular disease as "unequivocal."

People who eat diets high in alpha-linolenic acid (ALA), which is found in canola and flaxseed oils, have higher blood levels of omega-3 fatty acids than those consuming lower amounts, which may confer some protection against atherosclerosis.

Mediterranean Diet

In 1994, researchers conducted a study in people with a history of cardiovascular disease, using what they called the “Mediterranean” diet. The diet differed significantly from what people from Mediterranean countries actually eat, in that it contained little olive oil. Instead, the diet included a special margarine high in ALA. Those people assigned to the Mediterranean diet had a remarkable 70% reduced risk of dying from cardiovascular disease compared with the control group during the first 27 months. Similar results were also confirmed after almost four years.

The diet was high in beans and peas, fish, fruit, vegetables, bread, and cereals, and low in meat, dairy fat, and eggs. Although the authors believe that the high ALA content of the diet was partly responsible for the surprising outcome, other aspects of the diet may have been partly or even totally responsible for decreased death rates. Therefore, the success of the Mediterranean diet does not prove that ALA protects against cardiovascular disease.

Dietary Fiber

A systematic review of 20 years of research evaluated the association between dietary fiber and coronary heart disease. The meta-analysis portion of this review showed that regular whole grain foods are associated with a coronary heart disease risk reduction of about 26%.

In general, the fibers most linked to the reduction of cholesterol levels are found in oats, psyllium seeds, fruit (pectin) and beans (guar gum). An analysis of many soluble fiber trials proves that a cholesterol lowering effect exists, but the amount the cholesterol falls is quite modest. For unknown reasons, however, diets higher in insoluble fiber (found in whole grains and vegetables and mostly unrelated to cholesterol levels) have been reported to correlate better with protection against cardiovascular disease in both men and women. Some trials have used 20 grams of additional fiber per day for several months to successfully lower cholesterol.

Eggs & food high in cholesterol

Independent of their action on serum cholesterol, foods that contain high amounts of cholesterol - mostly egg yolks - can induce atherosclerosis. It makes sense to reduce the intake of egg yolks.

However, eating eggs does not increase serum cholesterol as much as eating saturated fat, and eggs may not increase serum cholesterol at all if the overall diet is low in fat. A decrease in atherosclerosis resulting from a pure vegetarian diet (no meat, poultry, dairy or eggs), combined with exercise and stress reduction, has been proven effective by controlled medical research.

Salt consumption

Preliminary evidence has suggested that excessive salt consumption is a risk factor for cardiovascular disease and death from cardiovascular disease in overweight people. Controlled trials are needed to confirm these observations.

Refined grains, sugars

Eating a diet high in refined carbohydrates (e.g., white flour, white rice, simple sugars) appears to increase the risk of coronary heart disease, and thus of myocardial infarctions, especially in overweight women.

However, controlled trials of reducing refined carbohydrate intake to prevent cardiovascular disease have not been attempted to confirm these preliminary findings.

Tocotrienols

Tocotrienols may offer protection against atherosclerosis by preventing oxidative damage to LDL cholesterol. In a double-blind trial in people with severe atherosclerosis of the carotid artery - the main artery supplying blood to the head - tocotrienol administration (200 mg per day) reduced the level of lipid peroxides in the blood. Moreover, people receiving tocotrienols for 12 months had significantly more protection against atherosclerosis progression, and in some cases reductions in the size of their atherosclerotic plaques, compared with those taking a placebo.

Omega-3 fatty acids

Supplementation with fish oil, rich in omega-3 fatty acids, has been associated with favorable changes in various risk factors for atherosclerosis and cardiovascular disease in some, but not all, studies. A double-blind trial showed that people with atherosclerosis who took fish oil (6 grams per day for 3 months and then 3 grams a day for 21 months) had significant regression of atherosclerotic plaques and a decrease in cardiovascular events (e.g., myocardial infarction and stroke) compared with those who did not take fish oil. These results contradict the findings of an earlier controlled trial in which fish oil supplementation for two years (6 grams per day) did not promote major favorable changes in the diameter of atherosclerotic coronary arteries.

Selenium

In some studies, people who consumed more selenium in their diet had a lower risk of cardiovascular disease. In one double-blind report, people who had already had one myocardial infarction were given 100 mcg of selenium per day or placebo for six months. At the end of the trial, there were four deaths from cardiovascular disease in the placebo group but none in the selenium group; however, the number of people was too small for this difference to be statistically significant. Some doctors recommend that people with atherosclerosis supplement with 100–200 mcg of selenium per day.

Homocysteine levels & vitamin C

Experimentally increasing homocysteine levels in humans has led to temporary endothelial dysfunction. Researchers are concerned this dysfunction may be linked to atherosclerosis and cardiovascular disease. Vitamin C has been reported in one controlled study to reverse the dysfunction caused by increases in homocysteine. Vitamin C also protects LDL.

Despite the protective mechanisms attributed to vitamin C, some research has been unable to link vitamin C intake to protection against cardiovascular disease. These negative trials have mostly been conducted using people who consume 90 mg of vitamin C per day or more—a level beyond which further protection of LDL may not occur. Studies of people who eat foods containing lower amounts of vitamin C have been able to show a link between dietary vitamin C and protection from cardiovascular disease. Therefore, leading vitamin C researchers have begun to suggest that vitamin C may be important in preventing cardiovascular disease, but only up to 100–200 mg of intake per day.47 In a double-blind trial, supplementation with 250 mg of timed-release vitamin C BID for three years resulted in a 15% reduction in the progression of atherosclerosis, compared with placebo. Many doctors suggest that people take vitamin C—often 1 gram per day—despite the fact that research does not yet support levels higher than 500 mg per day.

Vitamin E

Vitamin E is an antioxidant that serves to protect LDL from oxidative damage and has been linked to prevention of cardiovascular disease in double-blind research. Many doctors recommend 400–800 IU of vitamin E per day to lower the risk of atherosclerosis and myocardial infarctions. However, some leading researchers suggest taking only 100–200 IU per day, as studies that have explored the long-term effects of different supplemental levels suggest no further benefit beyond that amount, and research reporting positive effects with 400–800 IU per day have not investigated the effects of lower intakes.

In a double-blind trial, people with high cholesterol who took 136 IU of natural vitamin E per day for three years had 10% less progression of atherosclerosis compared with those taking placebo.

Homocysteine

Blood levels of homocysteine have been linked to atherosclerosis and cardiovascular disease in most research, though uncertainty remains about whether elevated homocysteine actually causes cardiovascular disease. Although some reports have found associations between homocysteine levels and dietary factors, such as coffee and protein intakes, evidence linking specific foods to homocysteine remains preliminary. Higher blood levels of vitamin B6, vitamin B12, and folic acid are associated with low levels of homocysteine and supplementing with these vitamins lowers homocysteine levels.

While several trials have consistently shown that B6, B12, and folic acid lower homocysteine, the amounts used vary from study to study. Many doctors recommend 50 mg of vitamin B6, 100–300 mcg of vitamin B12, and 500–800 mcg of folic acid. Even researchers finding only inconsistent links between homocysteine and cardiovascular disease have acknowledged that a B vitamin might offer protection against cardiovascular disease independent of the homocysteine-lowering effect. In one trial, people with normal homocysteine levels had demonstrable reversal of atherosclerosis when supplementing B vitamins (2.5 mg folic acid, 25 mg vitamin B6, and 250 mcg of vitamin B12 per day).

For the few cases in which vitamin B6, vitamin B12, and folic acid fail to normalize homocysteine, adding 6 grams per day of betaine (trimethylglycine) may be effective. Of these four supplements, folic acid appears to be the most important. Attempts to lower homocysteine by simply changing the diet rather than by using vitamin supplements have not been successful.

Quercetin

Quercetin, a flavonoid, protects LDL cholesterol from damage. While several preliminary studies have found that eating foods high in quercetin lowers the risk of cardiovascular disease,67 68 69 the research on this subject is not always consistent, and some research finds no protective link. Quercetin is found in apples, onions, black tea, and as a supplement. In some studies, dietary amounts linked to protection from cardiovascular disease are as low as 35 mg per day.

Evening Primrose

Though low levels (2 grams per day) of evening primrose oil appear to be without action, 3–4 grams per day have lowered cholesterol in double-blind research. Lowering cholesterol levels should in turn reduce the risk of atherosclerosis.

Chondrotin sulfate

Preliminary research shows that chondroitin sulfate may prevent atherosclerosis in animals and humans and may also prevent myocardial infarctions in people with pre-existing atherosclerosis. However, further research is needed to determine the value of chondroitin sulfate supplements for preventing or treating atherosclerosis.

Red wine - resveratrol

Preliminary studies have found that people who drink red wine, which contains resveratrol, are at lower risk of death from cardiovascular disease. Because of its antioxidant activity and its effect on platelets, some researchers believe that resveratrol is the protective agent in red wine. Resveratrol research remains very preliminary, however, and as yet there is no evidence that the amounts found in supplements help prevent atherosclerosis in humans.

Iron

In 1992, a Finnish study found a strong link between unnecessary exposure to iron and increased risk for cardiovascular disease. Since then many studies have not found that link, though perhaps an equal number have been able to confirm the outcome of the original report. One 1999 analysis of 12 studies looking at iron status and cardiovascular disease found no overall relationship, though another 1999 analysis of published studies came to a different conclusion. While the effect of unnecessary exposure to iron, including iron supplements, on the risk of cardiovascular disease remains unclear, there is no benefit in supplementing iron in the absence of a diagnosed deficiency.

Lycopene

The carotenoid, lycopene, has been found to be low in the blood of people with atherosclerosis, particularly if they are smokers. Although no association between atherosclerosis and blood level of any other carotenoid (e.g., beta-carotene) was found, the results of this study suggested a protective role for lycopene. Lycopene is present in high amounts in tomatoes.

Contraindications

Refer to the individual supplement for information about any side effects or interactions.

Garlic Directly anti-atherosclerotic
Fenugreek, garlic, guggul, psyllium Cholesterol-lowering
Green tea Block oxidation of cholesterol
Garlic, ginger, ginkgo, peony, turmeric Decrease excessive platelet aggregation
Butcher's broom, rosemary Traditionally considered circulatory stimulant

Garlic

Garlic has been shown to prevent atherosclerosis in a four-year double-blind trial. The preparation used, standardized for 0.6% allicin content, provided 900 mg of standardized garlic powder per day. The people in this trial were 50 to 80 years old, and the benefits were most notable in women. This trial points to the long-term benefits of garlic to both prevent and possibly slow the progression of atherosclerosis in people at risk.

Garlic has also lowered cholesterol levels in double-blind research, though more recently, some double-blind trials have not found garlic to be effective. Some of the negative trials have flaws in their design.Nonetheless, the relationship between garlic and cholesterol-lowering is somewhat unclear.

Garlic has also been shown to prevent excessive platelet adhesion in humans. Allicin, often considered the main active component of garlic, is not alone in this action. The constituent known as ajoene has also shown beneficial effects on platelets. Aged garlic extract, but not raw garlic, has been shown, to prevent oxidation of LDL cholesterol in humans, an event believed to be a significant factor in the development of atherosclerosis.

Ginkgo

Ginkgo may reduce the risk of atherosclerosis by interfering with a chemical the body sometimes makes in excess, called platelet activating factor (PAF). PAF stimulates platelets to stick together too much; ginkgo stops this from happening. Ginkgo also increases blood circulation to the brain, arms, and legs.

Garlic and ginkgo also decrease excessive blood coagulation. Both have been shown in double-blind and other controlled trials to decrease the overactive coagulation of blood that may contribute to atherosclerosis.

Guggul

Guggul has been less extensively studied, but double-blind evidence suggests it can significantly improve cholesterol and triglyceride levels in people. Numerous medicinal plants and plant compounds have demonstrated an ability to protect LDL cholesterol from being damaged by free radicals. Garlic, ginkgo, and guggul are of particular note in this regard. Garlic and ginkgo have been most convincingly shown to protect LDL cholesterol in humans.

Other herbs

Several other herbs have been shown in research to lower lipid levels. Of these, psyllium has the most consistent backing from multiple double-blind trials showing lower cholesterol and triglyceride levels.The evidence supporting the ability of fenugreek to lower lipid levels is not as convincing, coming from preliminary studies only.

Since oxidation of LDL cholesterol is thought to be important in causing or accelerating atherosclerosis, and green tea protects against oxidation, this herb may have a role in preventing atherosclerosis. However, while some studies show that green tea is an antioxidant in humans, others have not been able to confirm that it protects LDL cholesterol from damage. Much of the research documenting the health benefits of green tea is based on the amount of green tea typically drunk in Asian countries - about three cups per day (providing 240-320 mg of polyphenols).

The research on ginger's ability to reduce platelet aggregation indicates that 10 grams (approximately 1 heaping teaspoon) per day is the minimum necessary amount to be effective. Lower amounts of dry ginger, as well as various levels of fresh ginger, have not been shown to affect platelets.

Turmeric's active compound curcumin has shown potent anti-platelet activity in animal studies. It has also demonstrated this effect in preliminary human studies. In a similar vein, bilberry has been shown to prevent platelet aggregation as has peony. However, none of these three herbs has been documented to help atherosclerosis in human trials.

Butcher's broom and rosemary are not well studied as being circulatory stimulants but are traditionally reputed to have such an action that might impact atherosclerosis. While butcher's broom is useful for peripheral vascular disease, it also exerts effects that are protective for arteries.

Contraindications

Refer to the individual herb for information about any side effects or interactions.