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,
diabetes, high cholesterol has proven to be one of the most important promoters of
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
is taken into account. LDL (“bad”) cholesterol, HDL (“good”) cholesterol, and
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,270 but, 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.271-276 What 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
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
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.
If your primary problem is elevated triglycerides, see the
Stanols are 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.10 Because 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.
double-blind, placebo-controlled studies, ranging in length from 30 days to 12 months, have found stanol esters and their chemical relatives effective for improving cholesterol profile levels.2-15,167-169,174,175,263,280 The 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 oil has 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.20,21,170,241,278 According 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.170 Stanols 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
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%.22-27 Niacin 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.29 Unfortunately, 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
Water-soluble fiber supplements (such as
psyllium, hydroxymethylcellulose and its relatives, and
beta glucan from oats) are thought to lower cholesterol,253,263,291 and the FDA has permitted products containing this form of fiber to carry a "heart-healthy" label.31 It 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 appears capable of modestly lowering total cholesterol, LDL ("bad") cholesterol, and triglycerides by approximately 5%-15%.32,238,287 The 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.33 Higher 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.34-41,153,158-161,190-194,256,277,288,290 Other 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
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 leaf extract 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.82 A compound in artichoke called luteolin may play a role in reducing cholesterol.83
Red yeast rice
is a traditional Chinese medicinal substance. It is made by fermenting a type of yeast called
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
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
There are several other promising alternative treatments for high cholesterol. Approaches that specifically lower triglycerides (such as
fish oil) are discussed in the
Numerous studies enrolling a total of many thousands of individuals purported to show that the substance
policosanol, made from sugarcane, can markedly improve cholesterol profile. However, the single Cuban research group behind these studies has a financial connection to the product. It was not until 2006 that independent research groups began to report their results on the use of policosanol for hyperlipidemia. Currently, 9 such independent studies have been reported, enrolling more than 500 people, and in not one of these studies has policosanol proved to be more effective than placebo. See the full Policosanol
article for detailed information.
In a 12-month study of 223 postmenopausal women,
calcium supplements (calcium citrate at a dose of 1 g daily) significantly improved the ratio of HDL ("good") cholesterol to LDL ("bad") cholesterol.155
This appears to have been primarily due to a meaningful rise in HDL levels.
Krill are tiny shrimp-like crustaceans that flourish in the Antarctic Ocean and provide food for numerous aquatic animals.
Krill oil, similar but not identical to
fish oil, may improve cholesterol profile.204 Fish oil may enhance the effectiveness of drugs in the statin family.252,264 EPA, another constituent of fish oil, may help prevent severe heart complications in people with high cholesterol already taking statins.254
One double-blind study found evidence that
cinnamon, taken at a dose of 1-6 grams daily, improved triglyceride, LDL cholesterol, and total cholesterol, without worsening HDL cholesterol.198
Inconsistent evidence hints that
might reduce LDL cholesterol and, overall, slow down
atherosclerosis.95,96,98-100,157,208,284 Flaxseed oil may be helpful as well, although evidence is again inconsistent.209,242 It may be the generic fiber and not the other specific ingredients in flaxseed that benefit cholesterol levels.97,184 Studies of purified lignans (found in flaxseed) have yielded mixed results.210,269
A growing body of evidence suggests that increased consumption of nuts such as almonds, walnuts, pecans, and macadamia nuts may improve lipid profile and reduce heart disease risk, presumably because of their high monounsaturated fat content.101-109,163,211-212,281
Olive oil is known to improve cholesterol profile. Up until recently, it has been thought that the monounsaturated fats in olive oil are its primary active ingredients. However, some evidence hints that polyphenols in olive oil (particularly, virgin olive oil) may play a positive role as well.239
Some but not all studies suggest that "friendly" bacteria (
probiotics) might be able to improve cholesterol profile.123-128,213, 250
prebiotics," substances that enhance the growth of friendly bacteria, have shown inconsistent benefit in studies as well.214-221 One study found that any improvement, if it does occur, is short-lived.262
enriched with either theaflavin
261 have shown promise for lowering cholesterol.201,293
There is some suggestion that without such enhancement, both green tea
and black tea
may be ineffective.
Dark chocolate contains substances related to those in black and green tea, and it too has shown some promise for improving cholesterol profile.243-244, 251,262
Other preliminary double-blind trials suggest potential benefit with the Iranian herb
the Peruvian herb caigua (
the Chinese caterpillar/fungus
cordyceps,224Ipomoea batatus (sweet potato),162 and a drink containing broccoli and cabbage.199
Chitosan, a type of insoluble fiber derived from crustacean shells, has been proposed for reducing cholesterol levels. But, current evidence suggests that if it does offer any benefits, they are minimal at best.84-92,147,148,187,197,225-226,285
A comprehensive review combining the results of 14 studies found that
glucomannan, a dietary fiber derived from the tubers of
Amorphophallus konjac, significantly reduced total and LDL cholesterol levels.289
Weaker, and in some cases inconsistent, evidence suggests potential benefit with
berberine (found in
Oregon grape, and
barberry);227,282 beta-hydroxy-beta-methylbutyrate (HMB);164 blue-green algae;129-131,233 conjugated linoleic acid (CLA);165 L-carnitine;185,230-232 Ayurvedic
Eclipta alba (also know as Bhringraja or Keshraja);257 grape polyphenols;228-229 mesoglycan;110-112
Studies on whether the mineral
chromium can improve cholesterol levels have returned mixed results.113-121
However, this mineral may offer benefit for people taking drugs in the
beta-blocker family. These medications, used for high blood pressure and other conditions, sometimes reduce HDL cholesterol levels. Chromium supplements may offset this side effect.122
One study provides preliminary evidence that the herb
black cohosh may improve lipid profiles in postmenopausal women.156
Rice bran oil, like other vegetables oils, appears to favorably change lipid profile as well as reduce heart disease risk in other ways.166, 234
Weaker evidence suggests that
gamma oryzanol, a substance found in rice bran oil, can also improve lipid profiles.
Substances related to vitamin E called
tocotrienols are sometimes promoted as improving cholesterol levels. However, while benefit has been reported in test-tube studies, animal studies, and nonblinded human trials, properly designed studies have failed to find it effective.177, 246-249
Other herbs and supplements sometimes recommended for high cholesterol include
He shou wu,
maitake, and royal jelly , but there is as yet no real evidence that they work.
A number of studies published in the 1980s and 1990s reported that various
garlic preparations, including raw garlic, stabilized garlic powder, and aged garlic, can lower cholesterol.68,69 However, several more recent and generally better-designed studies have found that if any benefits exist, they are so small as to be of little help in real life.70-76,202,235,245
lecithin is commonly believed to reduce cholesterol levels, evidence indicates that it does not work.178-182
guggul, the sticky gum resin from the mukul myrrh tree, has been widely marketed as a cholesterol-reducing herb. However, while preliminary studies found evidence of benefit,77-80 they all suffered from significant design flaws; a well-designed study did not find guggul effective.186
Vitamin C,203 cranberry,236 curcumin (turmeric),267
have failed to prove effective in studies thus far.
One study failed to find special fats called
medium-chain triacylglycerols (MCTs) more effective for reducing cholesterol than ordinary unsaturated fats.183
A small randomized trial involving 67 people with high cholesterol found evidence to support the use of
sage leaf extract (500 mg every 8 hours) for modestly lowering total and LDL cholesterol levels.294