Atherosclerosis

• Tocotrienols: Tocotrienols (200 mg per day) may offer protection against atherosclerosis by preventing oxidative damage to LDL cholesterol. In a double-blind study in patients with severe atherosclerosis of the carotid artery - the main artery supplying blood to the head - tocotrienol supplementation reduced the size of the atherosclerotic plaques; in contrast, none of the patients receiving the placebo showed an improvement in their atherosclerosis.

• Fish oil: Rich in omega-3 fatty acids, fish oil has been associated with favorable changes in various risk factors for atherosclerosis and heart disease in some, but not all, studies (1-2 grams three times per day is often used).
• Folic acid: 500-800 mcg per day to lower homocysteine levels.
• Selenium: 100-200 mcg per day.
• Vitamin C: Leading vitamin C researchers have begun to suggest that vitamin C may be important in preventing heart disease, but only up to 100-200 mg of intake per day. In a double-blind trial, supplementation with 250 mg of timed-release vitamin C twice daily 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 (400-800 IU per day to prevent oxidative damage to LDL cholesterol) may lower the risk of atherosclerosis and heart attacks, but current evidence from large, well-designed studies is conflicting.

• Garlic: Garlic has been shown to be an effective anti-atherosclerotic at 900 mg per day (standardized extract).

• Fenugreek: (18 grams per day of powder), garlic (600-900 mg per day), guggul (25 mg guggulsterone three times a day), psyllium (5-10 grams per day).
• Green tea (three cups per day [providing 240-320 mg of polyphenols]) has been shown to block oxidation of cholesterol.
• Garlic has been shown to decrease excessive platelet stickiness.

• Meat and dairy: Reduce consumption of meat and dairy fat.
• Trans fatty acids: Avoid foods that contain trans fatty acids (margarine, partially hydrogenated vegetable oils).
• Alpha-linolenic acid: Opt for foods rich in alpha-linolenic acid (e.g., canola and flaxseed oils).
• Fiber: Certain fibers are linked to the reduction of cholesterol levels. They are found in oats, psyllium seeds, fruit (pectin), and beans (guar gum).
• Egg-yolks: High consumption of egg yolks may be able to induce atherosclerosis, independent of their action on serum cholesterol; therefore, people should reduce egg-yolk intake.
• Vegan diet: A vegan diet (i.e., no animal products) combined with exercise and stress reduction has been proven to reduce the incidence of atherosclerosis. (Note: people on a vegan diet need to be sure they are getting enough vitamin B12)
• Salt: Reduce salt consumption.

• Smoking: Smoking is directly linked to atherosclerosis. Quitting smoking is a critical step in the process of heart disease prevention.
• Weight loss: Obesity and type A behavior (time conscious, impatient, and aggressive) are both associated with an increased risk of atherosclerosis.
• Exercise: Exercise is linked to protection from atherosclerosis.

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.

Smoking

Virtually all doctors acknowledge the abundant evidence that smoking is directly linked to atherosclerosis and cardiovascular disease. Quitting smoking protects many people and is a critical step in the process of disease prevention.

Weight

Obesity, stress, and sedentary lifestyle are associated with an increased risk of atherosclerosis; interventions designed to change these risk factors are linked to protection from this condition.

Type A Behavior

Type A behavior (time conscious, impatient, and aggressive), and stress, especially combined with asedentary lifestyle are important factors. Aggressive verbal or physical responses when angry have been consistently related to coronary atherosclerosis in numerous preliminary studies. A low level of social support, especially when combined with a high level of outwardly expressed anger has also been associated with accelerated progression of coronary atherosclerosis.

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. 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, 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

Many actions associated with herbal supplements may help prevent or potentially alleviate atherosclerosis. Herbs such as garlic and ginkgo appear to directly affect the hardened arteries by multiple mechanisms. Herbs such as psyllium, guggul, and fenugreek reduce cholesterol and other lipid levels in the blood - known risk factors for hardened arteries. A related group are herbs, including green tea, prevents the oxidation of cholesterol, an important step in protecting against atherosclerosis. Finally, there are herbs such as ginger and turmeric that reduce excessive stickiness of platelets, thereby reducing atherosclerosis.

Herbs and their action

See research index