One of the most significant discoveries in preventive medicine is that elevated levels of cholesterol in the blood accelerate atherosclerosis, a condition commonly known as hardening of the arteries. Along with high blood pressure, inactivity, smoking, and diabetes, high cholesterol has proven to be one of the most important promoters of heart disease, strokes, and peripheral vascular disease (blockage of circulation to the extremities, usually the legs).

Cholesterol does not directly clog arteries like grease clogs pipes. The current theory is that elevated levels of cholesterol irritate the walls of blood vessels and cause them to undergo harmful changes. Because most cholesterol is manufactured by the body itself, dietary sources of cholesterol (such as eggs) are not usually the most important problem. The relative proportion of unsaturated fats (from plants) and saturated fats (mainly from animal products) in the diet is more significant.

When the consequences of elevated cholesterol were first being researched, total cholesterol was the only measurement considered. Today, the overall lipid profile is taken into account. LDL (“bad”) cholesterol, HDL (“good”) cholesterol, and triglycerides are the most common measurements related to cholesterol. Lipoprotein A and oxidized LDL cholesterol are drawing increasing attention as well.

This change in emphasis has thrown some long-standing recommendations into confusion. For example, reducing total fat intake generally decreases total cholesterol. On this basis, medical authorities long ago adopted a policy of recommending low-fat diets. However, when you take into account other lipid measurements, it is now clear that reducing fat intake is not the clear blessing it first appeared to be. Low-fat diets improve total and LDL cholesterol levels, but worsen HDL and triglyceride levels. Conversely, low-carb, high-fat diets tend to raise levels of LDL and total cholesterol, but reduce triglycerides and raise HDL. Some researchers use these effects as “proof” that the low-fat diet is healthier,270but, in fact, the current state of knowledge does not tell us whether the changes in lipids produced by low-fat diets are better or worse than the changes produced by low-carb diets. It is possible that a diet low in carbs and high in mono-unsaturated fats (eg, olive oil) offers the best of both worlds, but this has not been conclusively proven.271-276What is clear is that losing weight is extremely important. If you are overweight and lose weight, your cholesterol profile is almost certain to improve.188

Increasing exercise and losing weight may produce adequate improvements in the lipid profile. If such lifestyle changes are not effective, however, there are many highly effective drugs to choose from. Medications in the statin family are most effective, and they have been shown to prevent heart attacks and reduce mortality. Other useful conventional options include ezetimibe (Zetia), fibrate drugs, and various forms of the vitamin niacin (discussed below).

There are several herbs and supplements that appear to help lower cholesterol levels. For some (such as stanols/sterols, vitamin B 3, fiber, and soy), the evidence is sufficiently strong to have produced mainstream acceptance.

Note: If your primary problem is elevated triglycerides, see the High Triglycerides article.

Stanols/Sterols

Stanolsare substances that occur naturally in various plants. Their cholesterol-lowering effects were first observed in animals in the 1950s. Since then, a substantial amount of research suggests that plant stanols (usually modified into stanol esters) can help to lower cholesterol in individuals with normal or mildly to moderately elevated cholesterol levels. Stanols are available in margarine spreads, salad dressings, and dietary supplement tablets. Related substances called plant sterols appear to have equivalent effects,173,189 and in this subsection we will refer to sterols and stanols and their esters somewhat interchangeably.

Plant stanol esters reduce serum cholesterol levels by inhibiting cholesterol absorption.10Because they are structurally similar to cholesterol, stanols (and sterols) can displace cholesterol from the "packages" that deliver cholesterol for absorption from the intestines to the bloodstream.1 The displaced cholesterol is then excreted from the body. This not only interferes with the absorption of cholesterol from food, it has the additional (and probably more important) effect of removing cholesterol from substances made in the liver that are recycled through the digestive tract.

Numerous double-blind, placebo-controlledstudies, ranging in length from 30 days to 12 months, have found stanol esters and their chemical relatives effective for improving cholesterol profile levels.2-15,167-169,174,175,263,280The combined results suggest that these substances can reduce total cholesterol and LDL ("bad") cholesterol by about 10%-15%.16,278,279 However, stanols/sterols do not appear to have any significant effect on HDL ("good") cholesterol or triglycerides.

Fish oilhas also been shown to have a favorable effect on fats in the blood, in particular triglycerides. A study investigating the possible benefit of combining sterols with fish oil found that together they significantly lowered total cholesterol, LDL-cholesterol and triglycerides, and raised HDL-cholesterol in subjects with undesirable cholesterol profiles.286

Individuals taking statin drugs may benefit from using stanols/sterols as well.20,21,170,241,278According to one study, if you are on statins and start taking sterol ester margarine as well, your cholesterol will improve to the same extent as if you doubled the statin dose.170Stanols or sterols also appear to enhance the effects of cholesterol-lowering diets.17,174

Stanols or sterols also appear to be safe and effective in helping to improve cholesterol profile in people with type 2 (adult-onset) diabetes.18,19,175

For more information, including dosage and safety issues, see the full Stanols article.

Niacin (Vitamin B 3)

The common vitamin niacin, also called vitamin B 3, is an accepted medical treatment for elevated cholesterol with solid science behind it. Several well-designed, double-blind, placebo-controlled studies have found that niacin reduced LDL cholesterol by approximately 10% and triglycerides by 25%, and raised HDL cholesterol by 20%-30%.22-27Niacin also lowers levels of lipoprotein A—another risk factor for atherosclerosis—by about 35%. Furthermore, long-term use of niacin has been shown to significantly reduce death rates from cardiovascular disease.28

Niacin appears to be a safe and effective treatment for high cholesterol in people with diabetes as well, and (contrary to previous reports) does not seem to raise blood sugar levels.29Unfortunately, niacin, if taken in sufficient quantities to lower cholesterol, can cause an annoying flushing reaction and occasionally liver inflammation.30 Close medical supervision is essential when using niacin to lower cholesterol.

Combining high-dose niacin with statin drugs (the most effective medications for high cholesterol) further improves lipid profile by raising HDL (“good”) cholesterol.149-151 Unfortunately, there are real concerns that this combination therapy could cause a potentially fatal condition called rhabdomyolysis.

A growing body of evidence, however, suggests that the risk is relatively slight in individuals with healthy kidneys. Furthermore, even much lower doses of niacin than the usual dose given to improve cholesterol levels (100 mg versus 1,000 mg or more) may provide a similar benefit.152 At this dose, the risk of rhabdomyolysis should be decreased.

Nonetheless, it is not safe to try this combination except under close physician supervision. Rhabdomyolysis can be fatal.

For more information, including dosage and safety issues, see the full Vitamin B3 article.

Soluble Fiber

Water-soluble fiber supplements (such as psyllium, hydroxymethylcellulose and its relatives, and beta glucanfrom oats) are thought to lower cholesterol,253,263,291and the FDA has permitted products containing this form of fiber to carry a "heart-healthy" label.31It must be kept in mind, however, that the bulk of the supporting evidence for this theory comes from studies of oats conducted by manufacturers of oat products.255 A typical dose of oat bran is 5 to 10 g with each meal and at bedtime; psyllium is taken at 10 g with each meal.

Soy Protein

Soy protein appears capable of modestly lowering total cholesterol, LDL ("bad") cholesterol, and triglycerides by approximately 5%-15%.32,238,287The FDA has allowed foods containing soy protein to make the "heart-healthy" claim on the label. One study suggests that substituting as little as 20 g daily of soy protein for animal protein can significantly improve cholesterol levels.33Higher doses appear to cause increased benefit.238

Although it was once thought that isoflavones are the active ingredients in soy responsible for improving cholesterol profile, evidence suggests otherwise.34-41,153,158-161,190-194,256,277,288,290Other substances, such as certain soy proteins, may be more important. However, it has been additionally suggested that soy protein must be kept in its original state to be effective. Ordinary soy protein extracts are somewhat damaged (“denatured”). In a double-blind study of 120 people, a special “preserved” soy protein extract proved more effective for improving cholesterol profile than standard denatured soy protein extracts.260

For more information, including dosage and safety issues, see the full Soy article.

Artichoke Leaf

Although primarily used to stimulate gallbladder function, artichoke leaf may be helpful for high cholesterol as well.

In a double-blind, placebo-controlled study of 143 individuals with elevated cholesterol, artichoke leaf extract significantly improved cholesterol readings.81 Total cholesterol fell by 18.5% as compared to 8.6% in the placebo group; LDL cholesterol fell by 23% versus 6%; and the LDL to HDL ratio decreased by 20% versus 7%. In a subsequent study of 75 otherwise healthy people with high cholesterol, artichoke leafextract significantly reduced total cholesterol compared to placebo, but it did not affect LDL, HDL, or triglycerides levels.283

Artichoke leaf may work by interfering with cholesterol synthesis.82A compound in artichoke called luteolin may play a role in reducing cholesterol.83

Red Yeast Rice

Red yeast rice is a traditional Chinese medicinal substance. It is made by fermenting a type of yeast called Monascus purpureus over rice. It contains cholesterol-lowering chemicals in the statin family, including one identical to the drug lovastatin. Like statin drugs, red yeast rice appears to be effective for improving various aspects of the lipid profile, including total cholesterol, LDL cholesterol, and the LDL/HDL ratio.205-206,259 Presumably it also presents the same safety risks as statins, compounded by the uncertainty regarding how much active drug any particular batch of red yeast rice contains.

In a 2011 review of 22 trials, researchers concluded that an alcohol extract of red yeast rice (called xuezhikang) was no more or less effective than statins in lowering levels of cholesterol and triglycerides in people with high cholesterol and/or high triglycerides.292 They also found that the supplement may be more effective than inositol nicotinate (another cholesterol-lowering medication) in reducing cholesterol levels.

For more information, including complete dosage and safety issues, see the full Red Yeast Rice article.