Although it is by no means the only major risk factor, elevated serum (blood) cholesterol is clearly associated with a high risk of heart disease.
Most doctors suggest cholesterol levels should stay under 200 mg/dl. As levels fall below 200, the risk of heart disease continues to decline. Many doctors consider cholesterol levels of no more than 180 to be optimal. A low cholesterol level, however, is not a guarantee of good heart health, as some people with low levels do suffer heart attacks.
Medical laboratories now subdivide total cholesterol measurement into several components, including LDL (“bad”) cholesterol, which is directly linked to heart disease, and HDL (“good”) cholesterol, which is protective. The relative amount of HDL to LDL is more important than total cholesterol. For example, it is possible for someone with very high HDL to be at relatively low risk for heart disease even with total cholesterol above 200. Evaluation of changes in cholesterol requires consultation with a healthcare professional and should include measurement of total serum cholesterol, as well as HDL and LDL cholesterol.
The following discussion is limited to information about lowering serum cholesterol levels or increasing HDL cholesterol using natural approaches. Because high cholesterol is linked to atherosclerosis and heart disease, people concerned about heart disease should also learn more about atherosclerosis.
What are the symptoms of high cholesterol?
This condition does not produce symptoms. Therefore, it is prudent to visit a health professional on a regular basis to have cholesterol levels measured.
Dietary changes that may be helpful for high cholesterol
Eating animal foods containing saturated fat is linked to high cholesterol levels1 and heart disease.2 Significant amounts of animal-based saturated fat are found in beef, pork, veal, poultry (particularly in poultry skins and dark meat), cheese, butter, ice cream, and all other forms of dairy products not labeled “fat free.” Avoiding consumption of these foods reduces cholesterol and has been reported to reverse even existing heart disease.3
Unlike other dairy foods, skimmed milk, nonfat yogurt, and nonfat cheese are essentially fat-free. Dairy products labeled “low fat” are not particularly low in fat. A full 25% of calories in 2% milk come from fat. (The “2%” refers to the fraction of volume filled by fat, not the more important percentage of calories coming from fat.)
In addition to large amounts of saturated fat from animal-based foods, Americans eat small amounts of saturated fat from coconut and palm oils. Palm oil has been reported to elevate cholesterol.4 5 Research regarding coconut oil is mixed, with some trials finding no link to heart disease,6 while other research reports that coconut oil elevates cholesterol levels.7 8
Despite the links between saturated fat intake and serum cholesterol levels, not every person responds to appropriate dietary changes with a drop in cholesterol. A subgroup of people with elevated cholesterol who have what researchers call “large LDL particles” has been reported to have no response even to dramatic reductions in dietary fat.9 (LDL is the “bad” cholesterol most associated with an increased risk of heart disease.) This phenomenon is not understood. People who significantly reduce intake of animal fats for several months but do not see significant a reduction in cholesterol levels should discuss other approaches to lowering cholesterol with a doctor.
Yogurt, acidophilus milk, and kefir are fermented milk products that have been reported to lower cholesterol in most,10 11 12 13 14 15 16 but not all, double-blind and other controlled research.17 18 19 Until more is known, it makes sense for people with elevated cholesterol who consume these foods, to select nonfat varieties.
Eating fish has been reported to increase HDL cholesterol20 and is linked to a reduced risk of heart disease in most,21 but not all, studies.22 Fish contains very little saturated fat, and fish oil contains EPA and DHA, omega-3 fatty acids that appear to protect against heart disease.23
Vegetarians have lower cholesterol24 and less heart disease25 than meat eaters, in part because they avoid animal fat. Vegans (people who eat no meat, dairy, or eggs) have the lowest cholesterol levels,26 and switching from a standard diet to a vegan diet, along with other lifestyle changes, has been reported to reverse heart disease in controlled research.27 28
Egg consumption does not appear to be totally safe, however, even for people consuming a low-fat diet. When cholesterol from eggs is cooked or exposed to air, it oxidizes. Oxidized cholesterol is linked to increased risk of heart disease.31 Eating eggs also makes LDL cholesterol more susceptible to damage, a change linked to heart disease.32
Whether or not egg eaters are more likely to die from heart disease is a matter of controversy. In one preliminary study, egg eaters had a higher death rate from heart disease, even when serum cholesterol levels were not elevated.33 However, another preliminary study found no evidence of an overall significant association between egg consumption, and risk of heart disease or stroke, except in people with diabetes.34 Until more is known, limiting egg consumption may be a good idea, particularly for people with existing heart disease or diabetes.
While coconut oil is high in saturated fat, some evidence suggests it does not cause unhealthy changes in blood cholesterol levels compared with other saturated fats. In a controlled study of people with high cholesterol, coconut oil resulted in higher total and LDL cholesterol levels compared with safflower oil (a polyunsaturated oil), but lower levels compared with butter, while HDL levels were similar for all three diets.35 Another controlled study compared coconut oil with canola oil,36 and found that coconut oil raised total and LDL cholesterol in people with high cholesterol who were not taking cholesterol-lowering drugs, but did not affect these levels in people who were taking these drugs. HDL levels were not reported in this study.
Oat bran is rich in a soluble fiber called beta-glucan. In 1997, the U.S. Food and Drug Administration passed a unique ruling that allowed oat bran to be registered as the first cholesterol-reducing food at an amount providing 3 grams of beta-glucan per day, although some evidence suggests this level may not be high enough to make a significant difference.45 Several double-blind and other controlled trials have shown that oat bran46 47 48 and oat milk49 supplementation may significantly lower cholesterol levels in people with elevated cholesterol, but only weakly lowers them in people with healthy cholesterol levels.50
Flaxseed, another good source of soluble fiber, has been reported to lower total and LDL cholesterol in preliminary studies.51 52 A double-blind trial found that while both flaxseed and sunflower seed lowered total cholesterol, only flaxseed significantly lowered LDL.53 Amounts of flaxseed used in these trials typically range from 30–50 grams per day. A controlled trial found that partially defatted flaxseed, containing 20 grams of fiber per day, significantly lowered LDL cholesterol, suggesting that at least one of the cholesterol-lowering components in flaxseed is likely to be the fiber in this product, as opposed to the oil removed from it.54 Controlled trials of flaxseed oil alone have shown inconsistent effects on blood cholesterol.55 56 57
Preliminary research on the effects of ALA from flaxseed has produced conflicting results. For example, ALA has improved parameters of arterial health that should protect people from heart disease, yet ALA may cause damage to LDL cholesterol.60 Such damage is believed to be a precursor to heart disease.
In 1994, researchers conducted a study in people with a history of heart disease, using what they called the “Mediterranean” diet.61 The diet was significantly different 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 heart disease compared with the control group during the first 27 months. Similar results were also confirmed after almost four years.62 Although cholesterol levels fell only modestly in the “Mediterranean” diet group, the positive results suggest that people with elevated cholesterol attempting to reduce the risk of heart disease should consider such a diet. 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 partially 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 heart disease.63
Trans fatty acids and margarine
Trans fatty acids (TFAs) are found in many processed foods containing partially hydrogenated oils. The highest levels occur in margarine. Margarine consumption is linked to increased risk of unfavorable changes in cholesterol levels95 and heart disease.96 Margarine and other processed foods containing partially hydrogenated oils should be avoided.
However, special therapeutic margarines are now available that contain substances, called phytostanols, that block the absorption of cholesterol.97 The FDA has approved some of these margarines as legitimate therapeutic agents for lowering blood cholesterol levels. The best-known of these products is Benecol™. The cholesterol-lowering effect of these margarines has been demonstrated in numerous double-blind and other controlled trials.98 99 100 101 102 103 104
Nuts contain many factors that could be responsible for protection against heart disease, including fiber, vitamin E, alpha-linolenic acid (found primarily in walnuts), oleic acid, magnesium, potassium, and arginine. Therefore, exactly how nuts lower cholesterol or lower the risk of heart disease remains somewhat unclear. Some doctors even believe that nuts may not be directly protective; rather, people busy eating nuts will not simultaneously be eating eggs, dairy, or trans fatty acids from margarine and processed food, the avoidance of which would reduce cholesterol levels and the risk of heart disease.128 129 Nonetheless, the remarkable consistency of research outcomes strongly suggests that nuts do help protect against heart disease. Although nuts are loaded with calories, a preliminary trial surprisingly reported that adding hundreds of calories per day from nuts for six months did not increase body weight in humans130 —an outcome supported by other reports.131 Even when increasing nut consumption has led to weight gain, the amount of added weight has been remarkably less than would be expected, given the number of calories added to the diet.132 Given the number of calories per ounce of nuts, scientists do not understand why moderate nut consumption apparently has so little effect on body weight.
Number and size of meals
Exercise increases protective HDL cholesterol,135 an effect that occurs even from walking.136 Total and LDL cholesterol are typically lowered by exercise, especially when weight-loss also occurs.137 Exercisers have a relatively low risk of heart disease.138 However, people over 40 years of age, or who have heart disease, should talk with their doctor before starting an exercise program; overdoing it may actually trigger heart attacks.139
Obesity increases the risk of heart disease,140 in part because weight gain lowers HDL cholesterol.141 Weight loss reduces the body’s ability to make cholesterol, increases HDL levels, and reduces triglycerides (another risk factor for heart disease).142 143 Weight loss also leads to a decrease in blood pressure.
Smoking is linked to a lowered level of HDL cholesterol144 and is also known to cause heart disease.145 Quitting smoking reduces the risk of having a heart attack.146
The combination of feelings of hostility, stress, and time urgency is called type A behavior. Men,147 148 but not women,149 with these traits are at high risk for heart disease in most, but not all, studies.150 Stress151 or type A behavior152 may elevate cholesterol in men. Reducing stress and feelings of hostility has reduced the risk of heart disease.153
Glucomannan is a water-soluble dietary fiber that is derived from konjac root. Controlled154 155 and double-blind156 157 trials have shown that supplementation with glucomannan significantly reduced total blood cholesterol, LDL cholesterol, and triglycerides, and in some cases raised HDL cholesterol. Effective amounts of glucomannan for lowering blood cholesterol have been 4 to 13 grams per day.
Test tube and animal studies indicate that policosanol is capable of inhibiting cholesterol production by the liver.158 159
Extensive preliminary and double-blind research in Cuba and other countries in Latin America has demonstrated that taking 10 to 20 mg per day of policosanol extracted from sugar cane results in significant changes in blood cholesterol levels, including total cholesterol (17 to 21% lower on average), LDL cholesterol (21 to 29% lower), and HDL cholesterol (7 to 29% higher).160 161 162 163 164 165 166 167 168 169 170
The combined results of nine double-blind trials indicate that supplementation with beta-hydroxy-beta-methylbutyrate (HMB) effectively lowers total and LDL cholesterol.171 All trials used 3 grams per day, taken for three to eight weeks.
Vitamin C appears to protect LDL cholesterol from damage.172 In some clinical trials, cholesterol levels have fallen when people with elevated cholesterol supplement with vitamin C.173 Some studies report that decreases in total cholesterol occur specifically in LDL cholesterol.174 Doctors sometimes recommend 1 gram per day of vitamin C. A review of the disparate research concerning vitamin C and heart disease, however, has suggested that most protection against heart disease from vitamin C, is likely to occur with as little as 100 mg per day.175
Pantethine, a byproduct of vitamin B5 (pantothenic acid), may help reduce the amount of cholesterol made by the body. Several preliminary176 177 178 179 180 and two controlled181 182 trials have found that pantethine (300 mg taken two to four times per day) significantly lowers serum cholesterol levels and may also increase HDL. However, one double-blind trial in people whose high blood cholesterol did not change with diet and drug therapy, found that pantethine was also not effective.183 Common pantothenic acid has not been reported to have any effect on high blood cholesterol.
Chromium supplementation has reduced total cholesterol,184 185 LDL cholesterol186 187 and increased HDL cholesterol188 189 in double-blind and other controlled trials, although other trials have not found these effects.190 191 One double-blind trial found that high amounts of chromium (500 mcg per day) in combination with daily exercise was highly effective, producing nearly a 20% decrease in total cholesterol levels in just 13 weeks.192
Brewer’s yeast, which contains readily absorbable and biologically active chromium, has also lowered serum cholesterol.193 People with higher blood levels of chromium appear to be at lower risk for heart disease.194 A reasonable and safe intake of supplemental chromium is 200 mcg per day. People wishing to use brewer’s yeast as a source of chromium should look for products specifically labeled “from the brewing process” or “brewer’s yeast,” since most yeast found in health food stores is not brewer’s yeast, and does not contain chromium. Optimally, true brewer’s yeast contains up to 60 mcg of chromium per tablespoon, and a reasonable intake is 2 tablespoons per day.
High amounts (several grams per day) of niacin, a form of vitamin B3, lower cholesterol, an effect recognized in the approval of niacin as a prescription medication for high cholesterol.195 The other common form of vitamin B3—niacinamide—does not affect cholesterol levels. Some niacin preparations have raised HDL cholesterol better than certain prescription drugs.196 Some cardiologists prescribe 3 grams of niacin per day or even higher amounts for people with high cholesterol levels. At such intakes, acute symptoms (flushing, headache, stomachache) and chronic symptoms (liver damage, diabetes, gastritis, eye damage, possibly gout) of toxicity may be severe. Many people are not able to continue taking these levels of niacin due to discomfort or danger to their health. Therefore, high intakes of niacin must only be taken under the supervision of a doctor.
Symptoms caused by niacin supplements, such as flushing, have been reduced with sustained-release (also called “time-release”) niacin products. However, sustained-release forms of niacin have caused significant liver toxicity and, though rarely, liver failure.197 198 199 200 201 One partial time-release (intermediate-release) niacin product has lowered LDL cholesterol and raised HDL cholesterol without flushing, and it also has acted without the liver function abnormalities typically associated with sustained-release niacin formulations.202 However, this form of niacin is available by prescription only.
In an attempt to avoid the side effects of niacin, alternative health practitioners increasingly use inositol hexaniacinate, recommending 500 to 1,000 mg, taken three times per day, instead of niacin.203 204 This special form of niacin has been reported to lower serum cholesterol but so far has not been found to cause significant toxicity.205 Unfortunately, compared with niacin, far fewer investigations have studied the possible positive or negative effects of inositol hexaniacinate. As a result, people using inositol hexaniacinate should not take it without the supervision of a doctor, who will evaluate whether it is helpful (by measuring cholesterol levels) and will make sure that toxicity is not occurring (by measuring liver enzymes, uric acid and glucose levels, and by taking medical history and doing physical examinations).
Soy supplementation has been shown to lower cholesterol in humans.206 Soy is available in foods such as tofu, miso, and tempeh and as a supplemental protein powder. Soy contains isoflavones, naturally occurring plant components that are believed to be soy’s main cholesterol-lowering ingredients. A controlled trial showed that soy preparations containing high amounts of isoflavones effectively lowered total cholesterol and LDL (“bad”) cholesterol, whereas low-isoflavone preparations (less than 27 mg per day) did not.207 However, supplementation with either soy208 or non-soy isoflavones (from red clover)209 in pill form failed to reduce cholesterol levels in a group of healthy volunteers, suggesting that isoflavone may not be responsible for the cholesterol-lowering effects of soy. Further trials of isoflavone supplements in people with elevated cholesterol, are needed to resolve these conflicting results.
Soy contains phytosterols. One such molecule, beta-sitosterol, is available as a supplement. Beta-sitosterol alone, and in combination with similar plant sterols, has been shown to reduce blood levels of cholesterol in preliminary210 and controlled211 trials. This effect may occur because beta-sitosterol blocks absorption of cholesterol.212 In studying the effects of 0.8, 1.6, and 3.2 grams of plant sterols per day, one double-blind trial found that higher intake of sterols tended to result in greater reduction in cholesterol, though the differences between the effects of these three amounts were not statistically significant.213
A synthetic molecule related to beta-sitosterol, sitostanol, is now available in a special margarine and has also been shown to lower cholesterol levels. In one controlled trial, supplementation with 1.7 grams per day of a plant-sterol product containing mostly sitostanol, combined with dietary changes, led to a dramatic 24% drop in LDL (“bad”) cholesterol compared with only a 9% decrease in the diet-only part of the trial.214 Other controlled and double-blind trials have confirmed these results.215 216 217 218 219 A review of double-blind trials on sitostanol found that a reduction in the risk of heart disease of about 25% may be expected from use of sitostanol-containing spreads, a larger clinical effect than that produced by people reducing their saturated fat intake.220
Tocotrienols, a group of food-derived compounds that resemble vitamin E, may lower blood levels of cholesterol, but evidence is conflicting. Although tocotrienols inhibited cholesterol synthesis in test-tube studies,221 222 human trials have produced contradictory results. Two double-blind trials found that 200 mg per day of either gamma-tocotrienol223 or total tocotrienols224 were more effective than placebo, reducing cholesterol levels by 13–15%. However, in another double-blind trial, 200 mg of tocotrienols per day failed to lower cholesterol levels,225 and a fourth double-blind trial found 140 mg of tocotrienols and 80 mg of vitamin E (d-alpha-tocopherol) daily resulted in no changes in total cholesterol, LDL cholesterol, or HDL cholesterol levels.226
Deficiency of the trace mineral, copper, has been linked to high blood cholesterol.227 228 In a controlled trial, daily supplementation with 3 to 4 mg of copper for eight weeks decreased blood levels of total cholesterol and LDL cholesterol, in a group of people over 50 years of age.229
Beta-glucan is a type of soluble fiber molecule derived from the cell wall of baker’s yeast, oats and barley, and many medicinal mushrooms, such as maitake. Beta-glucan is the key factor for the cholesterol-lowering effect of oat bran.230 231 232 233 As with other soluble-fiber components, the binding of cholesterol (and bile acids) by beta-glucan and the resulting elimination of these substances in the feces is very helpful for reducing blood cholesterol.234 235 236 Results from a number of double-blind trials with either oat- or yeast-derived beta-glucan indicate typical reductions, after at least four weeks of use, of approximately 10% for total cholesterol and 8% for LDL (“bad”) cholesterol, with elevations in HDL (“good”) cholesterol ranging from zero to 16%.237 238 239 240 241 For lowering cholesterol levels, the amount of beta-glucan used has ranged from 2,900 to 15,000 mg per day.
Some preliminary242 and double-blind243 244 trials have shown that supplemental calcium reduces cholesterol levels. Possibly the calcium is binding with and preventing the absorption of dietary fat.245 However, other research has found no substantial or statistically significant effects of calcium supplementation on total cholesterol or HDL (“good”) cholesterol.246 Reasonable supplemental levels are 800 to 1,000 mg per day.
In one double-blind trial,247 vitamin E increased protective HDL cholesterol, but several other trials,248 249 250 found no effect of vitamin E. However, vitamin E is known to protect LDL cholesterol from damage.251 Most cardiologists believe that only damaged LDL increases the risk of heart disease. Studies of the ability of vitamin E supplements to prevent heart disease have produced conflicting results,252 but many doctors continue to recommend that everyone supplement 400 IU of vitamin E per day to lessen the risk of having a heart attack.
L-carnitine is needed by heart muscle to utilize fat for energy. Some,253 254 but not all, preliminary trials report that carnitine reduces serum cholesterol.255 HDL cholesterol has also increased in response to carnitine supplementation.256 257 People have been reported in controlled research to stand a greater chance of surviving a heart attack if they are given L-carnitine supplements.258 Most trials have used 1 to 4 grams of carnitine per day.
Magnesium is needed by the heart to function properly. Although the mechanism is unclear, magnesium supplements (430 mg per day) lowered cholesterol in a preliminary trial.259 Another preliminary study reported that magnesium deficiency is associated with a low HDL cholesterol level.260 Intravenous magnesium has reduced death following heart attacks in some, but not all, clinical trials.261 Though these outcomes would suggest that people with high cholesterol levels should take magnesium supplements, an isolated double-blind trial reported that people with a history of heart disease assigned to magnesium supplementation experienced an increased number of heart attacks.262 More information is necessary before the scientific community can clearly evaluate the role magnesium should play for people with elevated cholesterol.
Chondroitin sulfate has lowered serum cholesterol levels in preliminary trials.263 264 Years ago, this supplement dramatically reduced the risk of heart attacks in a controlled, six-year follow-up of people with heart disease.265 The few doctors aware of these older clinical trials sometimes tell people with a history of heart disease or elevated cholesterol levels, to take approximately 500 mg of chondroitin sulfate three times per day.
Although lecithin has been reported to increase HDL cholesterol and lower LDL cholesterol,266 a review of the research found that the positive effect of lecithin was likely due to the polyunsaturated fat content of the lecithin.267 If this is so, it would make more sense to use inexpensive vegetable oil, rather than take lecithin supplements. However, an animal study found a cholesterol-lowering effect of lecithin independent of its polyunsaturate content.268 A double-blind trial found that 20 grams of soy lecithin per day for four weeks had no significant effect on total cholesterol, LDL cholesterol, HDL cholesterol, or triglycerides.269 Whether taking lecithin supplements is a useful way to lower cholesterol in people with elevated cholesterol levels remains unclear.
The fiber-like supplement chitosan may lower blood cholesterol.270 A preliminary trial reported that 3 to 6 grams per day of chitosan taken for two weeks resulted in a 6% drop in cholesterol and a 10% increase in protective HDL cholesterol.271 However, a double-blind trial found a smaller 2.4 gram daily dose did not produce significant beneficial changes in total, LDL, or HDL cholesterol.272
Royal jelly has prevented the cholesterol-elevating effect of nicotine273 and has lowered serum cholesterol in animal studies.274 Preliminary human trials have also found that royal jelly may lower cholesterol levels.275 276 An analysis of cholesterol-lowering trials shows that 50 to 100 mg per day is the typical amount used in such research.277
A double-blind trial found that 20 grams per day of creatine taken for five days, followed by ten grams per day for 51 days, significantly lowered serum total cholesterol and triglycerides, but did not change either LDL or HDL cholesterol, in both men and women.278 However, another double-blind trial found no change in any of these blood levels in trained athletes using creatine during a 12-week strength training program.279 Creatine supplementation in this negative trial was lower—only 5 grams per day were taken for the last 11 weeks of the study.
Octacosanol, a substance found in wheat germ oil, is sometimes available as a supplement. Small amounts (5 to 20 mg per day) of policosanol, an experimental supplement from Cuba consisting primarily of octacosanol, has led to large reductions in LDL cholesterol and/or increases in HDL.280 281 282 283 Octacosanol may lower cholesterol by inhibiting the liver’s production of cholesterol.284
Homocysteine, a substance linked to heart disease risk, may increase the rate at which LDL cholesterol is damaged.285 While vitamin B6, vitamin B12, and folic acid lower homocysteine,286 a recent trial found no effect of supplements of these vitamins on protecting LDL cholesterol, even though homocysteine was lowered.287
Are there any side effects or interactions with high cholesterol?
Refer to the individual supplement for information about any side effects or interactions.
Herbs that may be helpful for high cholesterol
Researchers have determined that one of the ingredients in red yeast rice, called monacolin K, inhibits the production of cholesterol by stopping the action of the key enzyme in the liver (i.e., HMG-CoA reductase) that is responsible for manufacturing cholesterol.288 The drug lovastatin (Mevacor®) acts in a fashion similar to this red-yeast-rice ingredient. However, the amount per volume of monacolin K in red yeast rice is small (0.2% per 5 mg) when compared to the 20 to 40 mg of lovastatin available as a prescription drug.289
The red yeast rice used in various studies was a proprietary product called Cholestin®, which contains ten different monacolins. The sale of Cholestin has been banned in the United States, as a result of a lawsuit alleging patent infringement. Other red yeast rice products currently on the market differ from Cholestin in their chemical makeup. None contain the full complement of 10 monacolin compounds that are present in Cholestin, and some contain a potentially toxic fermentation product called citrinin. 290 Until further information is available, red yeast rice products other than Cholestin cannot be recommended.
Use of psyllium has been extensively studied as a way to reduce cholesterol levels. An analysis of all double-blind trials in 1997 concluded that a daily amount of 10 grams psyllium lowered cholesterol levels by 5% and LDL cholesterol by 9%.291 Since then, a large controlled trial found that use of 5.1 grams of psyllium two times per day significantly reduced serum cholesterol as well as LDL-cholesterol.292 Generally, 5 to 10 grams of psyllium are added to the diet per day to lower cholesterol levels. The combination of psyllium and oat bran may also be effective at lowering LDL cholesterol.293
Guggul, a mixture of substances taken from a plant, is an approved treatment for elevated cholesterol in India and has been a mainstay of the Ayurvedic approach to preventing atherosclerosis. One double-blind trial studying the effects of guggul reported that serum cholesterol dropped by 17.5%.294 In another double-blind trial comparing guggul to the drug clofibrate, the average fall in serum cholesterol was slightly greater in the guggul group; moreover, HDL cholesterol rose in 60% of people responding to guggul, while clofibrate did not elevate HDL.295 A third double-blind trial found significant changes in total and LDL cholesterol levels, but not in HDL.296 However, in another double-blind trial, supplementation with guggul for eight weeks had no effect on total serum cholesterol, but significantly increased LDL-cholesterol levels, compared with a placebo.297 Daily intakes of guggul are based on the amount of guggulsterones in the extract. The recommended amount of guggulsterones is 25 mg taken three times per day. Most extracts contain 5 to 10% guggulsterones, and doctors familiar with their use usually recommend taking guggul for at least 12 weeks before evaluating its effect.
In a double-blind trial, people with moderately high cholesterol took a tincture of Achillea wilhelmsii, an herb used in traditional Persian medicine.298 Participants in the trial used 15 to 20 drops of the tincture twice daily for six months. At the end of the trial, participants experienced significant reductions in total cholesterol, LDL cholesterol and triglycerides, as well as an increase in HDL cholesterol compared to those who took placebo. No adverse effects were reported.
Reports on many double-blind garlic trials performed through 1998 suggested that cholesterol was lowered by an average of 9 to 12% and triglycerides by 8 to 27% over a one-to-four month period.299 300 301 Most of these trials used 600 to 900 mg per day of garlic supplements. More recently, however, several double-blind trials have found garlic to have minimal success in lowering cholesterol and triglycerides.302 303 304 305 One negative trial has been criticized for using a steam-distilled garlic “oil” that has no track record for this purpose,306 while the others used the same standardized garlic products as the previous positive trials. Based on these findings, the use of garlic should not be considered a primary approach to lowering high cholesterol and triglycerides.307
Part of the confusion may result from differing effects from dissimilar garlic products. In most but not all trials, aged garlic extracts and garlic oil (both containing no allicin) have not lowered cholesterol levels in humans.308 309 Therefore, neither of these supplements can be recommended at this time for cholesterol lowering. Odor-controlled, enteric-coated tablets standardized for allicin content are available and, in some trials, appear more promising.310 Doctors typically recommend 900 mg per day (providing 5,000 to 6,000 mcg of allicin), divided into two or three admininstrations.
Green tea has been shown to lower total cholesterol levels and improve people’s cholesterol profile, decreasing LDL cholesterol and increasing HDL cholesterol according to preliminary studies.311 312 313 314 However, not all trials have found that green tea intake lowers lipid levels.315 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 to 320 mg of polyphenols.
An extract of green tea, enriched with a compound present in black tea (theaflavins), has been found to lower serum cholesterol in a double-blind study of people with moderately high cholesterol levels.316 The average reduction in total serum cholesterol during the 12-week study was 11.3%, and the average reduction in LDL cholesterol was 16.4%. The extract used in this study provided daily 75 mg of theaflavins, 150 mg of green tea catechins, and 150 mg of other tea polyphenols.
Artichoke has moderately lowered cholesterol and triglycerides in some,317 but not all,318 human trials. One double-blind trial found that 900 mg of artichoke extract per day significantly lowered serum cholesterol and LDL cholesterol but did not decrease triglycerides or raise HDL cholesterol.319 Cholesterol-lowering effects occurred when using 320 mg of standardized leaf extract taken two to three times per day for at least six weeks.
Fenugreek seeds contain compounds known as steroidal saponins that inhibit both cholesterol absorption in the intestines and cholesterol production by the liver.320 Dietary fiber may also contribute to fenugreek’s activity. Multiple human trials (some double-blind) have found that fenugreek may help lower total cholesterol in people with moderate atherosclerosis or those having insulin-dependent or non-insulin-dependent diabetes.321 322 323 One human double-blind trial has also shown that defatted fenugreek seeds may raise levels of beneficial HDL cholesterol.324 One small preliminary trial found that either 25 or 50 grams per day of defatted fenugreek seed powder significantly lowered serum cholesterol after 20 days.325 Germination of the fenugreek seeds may improve the soluble fiber content of the seeds, thus improving their effect on cholesterol.326 Fenugreek powder is generally taken in amounts of 10 to 30 grams three times per day with meals.
Preliminary Chinese research has found that high doses (12 grams per day) of the herb fo-ti may lower cholesterol levels. Double-blind or other controlled trials are needed to determine fo-ti’s use in lowering cholesterol. A tea may be made from processed roots by boiling 3 to 5 grams in a cup of water for 10 to 15 minutes. Three or more cups should be drunk each day. Fo-ti tablets containing 500 mg each are also available. Doctors may suggest taking five of these tablets three times per day.
Wild yam has been reported to raise HDL cholesterol in preliminary research. Doctors sometimes recommend 2 to 3 ml of tincture taken three to four times per day, or 1 to 2 capsules or tablets of dried root taken three times per day. 327
Animal studies suggest that the mushroom maitake may lower fat levels in the blood.328 This research is still preliminary and requires confirmation with controlled human trials.
Animal studies indicate that saponins in alfalfa seeds may block absorption of cholesterol and prevent the formation of atherosclerotic plaques.329 However, consuming the large amounts of alfalfa seeds (80 to 120 grams per day) needed to supply high doses of these saponins may potentially cause damage to red blood cells in the body.330
Are there any side effects or interactions with high cholesterol?
Refer to the individual herb for information about any side effects or interactions.