What nutritional supplements are available to reduce cholesterol?
Artichoke: The discovery that artichoke leaf extract reduces elevated cholesterol levels opens up exciting perspectives in the prevention and treatment of arteriosclerosis and coronary heart disease.
It was as early as the 1930s that scientists first discovered that artichoke extract had a favorable effect on atherosclerotic plaques in the arteries (Tixier, 1939). Later animal studies, in which rats were fed a high-fat diet, also showed that artichoke extract prevented a rise in serum cholesterol levels and the manifestation of atherosclerotic plaque (Samochowiec, 1959 and 1962).
In addition to findings in animal experiments (Samochowiec et al., 1971; Frohlich and Ziegler, 1973; Wojcicki 1976; Lietti 1977 and 1978), a study by Fintelmann in 1996 of 553 outpatients demonstrated a significant effect of the extract on fat (lipid) metabolism. The researchers found a significant decline in both the cholesterol and triglyceride levels in the blood, which confirmed a discovery made as early as the 1930s.
Recent research confirms these earlier findings. The study by Fintelmann demonstrated a significant reduction in cholesterol and triglyceride levels in spite of the relatively short duration of the study (6 weeks). On an average, there was an 11.5% reduction in serum cholesterol from 264 mg/dL initially to 234 mg/dL. Serum triglycerides were similarly reduced from 215 mg/dL initially to 188 mg/dL, corresponding to a decrease of 12.5%. Although this was an open study, its reliability is buttressed by the relatively large number of patients (302) and the very high level of statistical significance attained for the main results.
Artichoke extract may work through indirect inhibition of the enzyme HMGCoA-reductase, which might avoid problems known to occur with strong direct inhibitors of HMGCoA-reductase during long-term treatment. The indirect inhibition was supported by the fact that artichoke leaf extract effectively blocked insulin-dependent stimulation of HMGCoA-reductase without affecting insulin in general. HMGCoA-reductase is a key enzyme in cholesterol synthesis, and HMGCoA-reductase inhibitors generally reduce total cholesterol, low-density lipoprotein cholesterol and triglyceride levels
Artichokes contain a compound called cynarin, which increases the liver's production of bile. Studies show that the extract also boosts the flow of bile from the gallbladder. Bile plays a key role in the excretion of excess cholesterol from the body. Artichoke supplements are free of side effects, and in my clinical experience, artichoke is a highly effective cholesterol reducer.
Traditional healers prescribed artichoke leaf to treat digestive upset, poor liver function, and a range of other ailments. Its primary use has been as a choleretic--a substance that strengthens liver function by increasing bile production. Artichoke leaf also has a centuries-old reputation as a diuretic (to increase urination).
Ongoing research seems to indicate that artichoke does indeed have medicinal qualities. Most significant appears to be its beneficial effect on the liver. In animal studies, liquid extracts of the roots and leaves of artichoke have demonstrated an ability to protect the liver, and possibly even to help liver cells regenerate. Although research is not yet conclusive, scientists are optimistic that its long-standing use in humans for digestive and bowel problems is indeed justified. It may also play a role in lowering cholesterol and thus help to prevent heart disease.
Artichoke is particularly helpful in relieving gastrointestinal problems that result from an inability to adequately process fats, a result of poor bile secretion. Because it stimulates the liver to produce of this important gastric "juice," artichoke can help to ease upset stomach symptoms such as nausea, bloating, abdominal pain, and vomiting. Artichoke leaf is also reputed to relieve flatulence. Cynarin, an artichoke extract, has recently been listed in the The Merck Index, a pharmaceutical guide, for this use.
Secreting bile helps the liver to regulate its production of cholesterol. Given artichoke's role in boosting bile output, researchers have examined whether artichoke lowers cholesterol. While results have been inconsistent, some manufacturers have nonetheless added cynarin, the artichoke extract, to their cholesterol-lowering drugs.
Garlic: Cholesterol - a white, waxy substance found in the blood plasma - is essential to life. However overly high cholesterol levels can have serious health implications on the cardiovascular system in particular leading to atherosclerosis. Excessive cholesterol levels can be an indicator of increased risk of heart attack and/or stroke.
Garlic has been reputed to assist the heart for centuries and has been used in herbal medicines for all manner of conditions. Garlic & cholesterol reduction are frequently mentioned together.
Modern medical science suggests one reason garlic might reduce cholesterol: garlic is a proven anti-oxidant. This property might help to prevent LDLs from being oxidised. In this way the cholestrol build-up that clogs the arteries could perhaps be reduced by garlic.
In recent decades, numerous scientific studies have been conducted to test the claims regarding garlic and cholesterol. These studies involve measuring the cholesterol and triglyceride levels of patients taking garlic supplements compared with a control group of patients taking a placebo. Unfortunately the results are not conclusive. Some studies have shown a reduction in total cholesterol levels and/or low-density lipoprotein levels in those taking garlic. Other medical studies have shown no significant difference between the cholestrol levels of those taking garlic and those taking a placebo.
Garlic reduces blood pressure & cholesterol and helps prevent blood clots that trigger heart attack. Garlic kills the bacteria that cause tuberculosis, food poisoning, bladder infections & fungi that cause athletes foot and vaginal yeast infections. In the First World War, garlic was prescribed to prevent and treat dysentery. European studies show that garlic helps eliminate lead and other heavy metals in the body. Children are particularly susceptible to lead effects, as it interferes with thinking and causes other serious health problems.
The cardioprotective benefits associated with garlic are generally attributed to the various sulfur compounds that can be isolated from the raw clove. These compounds, which include alliin, allicin, S-allyl-cysteine, S-methyl-cysteine and many others are found in varying concentrations in garlic, chives, leeks, shallots and onions, but the chemical composition may vary considerable depending on processing methods. The chemical responsible for the pungent smell of garlic, allicin, is produced from alliin via the action of alliinase and is thought to contribute to many of the health effects associated with garlic supplements.
If you have high LDL cholesterol levels, garlic supplementation is especially important because LDL cholesterol oxidation causes atherosclerosis, and garlic specifically inhibits LDL oxidation. And garlic helps protect the arterial lining against oxidation. Most importantly, garlic prevents abnormal platelet aggregation (thrombosis) via several different mechanisms. The formation of arterial blood clots is the primary cause of most heart attacks and strokes.
Investigators reported in a study published in the American Journal of Clinical Nutrition (1996, 64:866-70) that the daily administration of 7.2 grams of Kyolic garlic powder for 6 months produced a modest reduction (of between 6.1 and 7%) in total cholesterol, compared with the placebo group. The more dangerous low-density lipoprotein cholesterol was reduced 4 to 4.6% in the Kyolic group.
The heart-healthy benefits of garlic include protecting the endothelial lining of the arterial system against oxidative damage. A study published in Atherosclerosis (1999, 144:237-49) shows an actual reduction in buildup of fatty plaque in arteries in garlic-supplement users. Fatty plaque is comprised of many substances, including cholesterol. When plaque accumulates in the coronary arteries, the condition can lead to heart attack. In a study of 280 adults, German researchers reported that participants who took 900 mg of garlic powder a day had up to 18% less plaque in their arteries than those who took a placebo, or "dummy," powder. Male study participants who took a placebo had a 5.5% increase in plaque volume, while those who took the garlic powder experienced just a 1.1% increase in plaque buildup during the 4-year study period. By comparison, women who took the garlic showed a 4.6% decrease in plaque volume, while those who took the placebo powder had a 5.3% increase. Garlic may affect plaque buildup by reducing blood platelet stickiness (aggregation) and specifically preventing the oxidation of low-density lipoprotein cholesterol onto the lining of the arteries. Platelet aggregation helps plaque cling to the arteries.
An April 1998 study reported on the effect of garlic on blood lipids, blood sugar fibrogen, and fibrinogenic activity of 30 patients who received 4 grams of garlic daily for 3 months. The patients were monitored at 1.5 and 3 months when it was determined that garlic had "significantly reduced total serum cholesterol and triglycerides, and significantly increased HDL cholesterol." With regard to fibrinogenic activity, it was determined that the garlic inhibited platelet aggregation (Prostagland. Leuk. Essent. Fatty Acids, April 1998, 58:257-63).
In summary, the mechanisms by which garlic have shown to protect against cardiovascular disease include the following: cholesterol reduction, preventing abnormal blood clot formation inside of blood vessels; protecting against low-density lipoprotein cholesterol oxidation; and protecting the endothelial lining of the arterial system against oxidation. A review of all the studies on garlic indicates that high doses are required for effective cholesterol reduction. If you were to use garlic alone to lower serum cholesterol, you should take 6000 to 8000 mg a day. When used in combination with other cholesterol-lowering nutrients, lower doses of garlic may be effective.
Curcumin: Curcumin, also known as turmeric root, an ancient spice in the ginger family, is gaining attention for its positive impact on a number of diseases, including cholesterol reduction. Scientific evidence has been building since the mid-1980s of curcumin's potential cholesterol-lowering capabilities.
Several studies have reported that Curcumin is beneficial in lowering LDL and raising HDL or good cholesterol while reducing the lipid peroxidation. Ten human volunteers were given 500 mg of curcumin for seven days during a controlled trial at Amala Cancer Research Centre in India. After seven days, they noted a 29% increase in good cholesterol (HDL) and a reduction of 11.6% total cholesterol. Lipid peroxidation was also reduced by 33%. Another study published in Atherosclerosis in Dec. 1999 by the Faculty of Pharmacy at the University of Granada reported that curcumin was effective in inhibiting low-density lipoprotein oxidation and lowering LDL cholesterol as well as triglycerides. According to the latest research, curcumin reduces cholesterol by interfering with intestinal cholesterol uptake, increasing the conversion of cholesterol into bile acids, and increasing the excretion of bile acids (International Journal of Vitamin Nutritional Research, 1991, 61:364-69). Another 2000 study shows that "a daily oral administration of the curcumin extract significantly decreases LDL and apo B (a leading heart disease risk factors) and increases the HDL and apo A of healthy subjects."
The volatile oil fraction of turmeric has been demonstrated significant anti-inflammatory activity in a variety of experimental models. Even more potent than its volatile oil is the yellow or orange pigment of turmeric, which is called curcumin. Curcumin is thought to be the primary pharmacological agent in turmeric. In numerous studies, curcumin's anti-inflammatory effects have been shown to be comparable to the potent drugs hydrocortisone and phenylbutazone as well as over-the-counter anti-inflammatory agents such as Motrin. Unlike the drugs, which are associated with significant toxic effects (ulcer formation, decreased white blood cell count, intestinal bleeding), curcumin produces no toxicity.
Curcumin may be able to prevent the oxidation of cholesterol in the body. Since oxidized cholesterol is what damages blood vessels and builds up in the plaques that can lead to heart attack or stroke, preventing the oxidation of new cholesterol may help to reduce the progression of atherosclerosis and diabetic heart disease. In addition, turmeric is a very good source of vitamin B6, which is needed to keep homocysteine levels from getting too high. Homocysteine, an intermediate product of an important cellular process called methylation, is directly damaging to blood vessel walls. High levels of homocysteine are considered a significant risk factor for blood vessel damage, atherosclerotic plaque build-up, and heart disease; while a high intake of vitamin B6 is associated with a reduced risk of heart disease.
Curcumin also provides an additional benefit by potentially reducing the risk of cardiovascular-related disease as it inhibits platelet aggregation and significantly decreases the level of lipid (LDL) peroxidation. "Observation of curcumin's mechanism of action shows that it blocks the formation of thromboxane A2, a promoter of platelet aggregation, thereby inhibiting abnormal blood clot formation. Curcumin also increases a prostacyclin, a natural inhibitor of platelet aggregation" (Arzneim. Forsch., 1986, 36:715-17).
Green Tea: Green tea has been shown to lower "bad" LDL cholesterol and serum triglyceride levels. Further, green tea's potent antioxidant effects inhibit the oxidation of LDL cholesterol in the arteries, which plays a major contributory role in the formation of atherosclerosis.
Green tea contains volatile oils, vitamins, minerals, and caffeine, but the primary constituents of interest are the polyphenols, particularly the catechin called epigallocatechin gallate (EGCG). The polyphenols are believed to be responsible for most of green tea's roles in promoting good health.
Green tea has been shown to mildly lower total cholesterol levels and improve the cholesterol profile (decreasing LDL "bad" cholesterol and increasing HDL "good" cholesterol) in most, but not all, studies. Green tea may also promote cardiovascular health by making platelets in the blood less sticky.
Green tea has also been shown to protect against damage to LDL ("bad") cholesterol caused by oxygen. Consumption of green tea increases antioxidant activity in the blood.8 Oxidative damage to LDL can promote atherosclerosis. While population studies have suggested that consumption of green tea is associated with protection against atherosclerosis, the evidence is still preliminary.
The cholesterol-lowering (hypocholesterolemic) effects of green tea (as well as black tea) have been confirmed by both animal and human epidemiological studies. High consumption of green tea by humans, especially more than 10 cups a day, was found to be associated with higher HDLs and lower LDL and VLDL cholesterol, as well as with various biomarkers indicating better liver health. Lower levels of lipid peroxides in the liver are one well-confirmed benefit of green-tea supplementation found in study after study.
Green tea also has been shown to elevate levels of HDL, the good cholesterol that helps remove atherosclerotic plaque from arterial walls. Green tea is a natural ACE inhibitor. This is an extra benefit for those with high cholesterol and blood pressure, as published studies show lowered blood pressure in animals and humans given green tea extracts. We recommend one capsule (350 mg) of green tea 95% extract daily, or drinking one to ten cups of green or black tea a day.
Fish Oil: Fish oil has been shown to reduce high levels of triglycerides by an average of 35%. Fish oil does not appear to reduce cholesterol to that extent, but does offer benefits when consumed as part of an integrated therapy.
Investigations published in the American Journal of Clinical Nutrition in 1997 examined the effects of n-3 fatty acids on serum lipid and lipoprotein concentrations in seven species of experimental animals. n-3 Fatty acids consistently lower serum triglyceride concentrations in humans, but not in most animals. These differences between animals and humans may arise from underlying species differences in lipoprotein metabolism.
Scientific studies have demonstrated that alpha-linolenic acid (from flax or perilla oil) reduces the incidence of atherosclerosis, stroke, and second heart attacks. One study showed a 70% reduction in second heart attacks in those consuming this type of fatty acid. Additionally, perilla oil suppresses platelet-activating factor (PAF), a major cause of arterial blood clots that cause heart attacks and strokes. Perilla oil was shown to decrease PAF by 50% in rats, compared with the administration of safflower oil.
Fish oil and garlic is a beneficial combination: Forty subjects, all with cholesterol over 200 mg/dL, were enrolled in a single-blind, placebo-controlled crossover study to evaluate both fish oil and garlic extract used in a synergistic regimen. Each patient received 1800 mg of fish oil plus 1200 mg of garlic for 1 month. Crossovers were then made to placebos for 1 month. This study found an 11% decrease in cholesterol, a 34% decrease in triglycerides, and a 10% decrease in LDL levels as well as a 19% decrease in HDL risk. Although not significant, there was a trend toward increase in HDL. The doctors concluded by stating
These results suggest that in addition to the known anticoagulant and antioxidant properties of both fish oil and garlic, the combination causes favorable shifts in the lipid subfractions within 1 month. Triglycerides are affected to the largest extent. The cholesterol lowering and improvement in lipid/HDL risk ratios suggests that these combinations may have antiatherosclerotic properties and may protect against the development of coronary artery disease.
Although fish oil appears to be beneficial for cholesterol reduction, there is a remaining problem: fish and flax oil, traditional sources of omega-3 fatty acids, can cause gastrointestinal side effects as well a stomach upset. There is good news in this regard; a new source of essential fatty acids, perilla oil, is showing superior health benefits without adverse gastrointestinal side effects. For cardiovascular disease risk reduction, we recommend 6000 mg of perilla oil a day.
Vitamin E: To say that vitamin E is very important to our health is an understatement: it is protective against approximately 80 diseases. Vitamin E may help inhibit and slow the development of LDL oxidation, the progression of cardiovascular-related diseases, and possibly slow aging. Vitamin E has the ability to stabilize free radicals. Free radicals are unstable oxygen molecules that can break down and degenerate cells, much as oxygen causes rust on iron. Partly caused by increased LDL cholesterol oxidation, free radicals result in increased plaque deposits and restricted blood flow, making them extremely dangerous to the interior of arteries.
Increased blood cell adhesion to human aortic endothelial cells (ECs) lining veins and arteries is one of the early events in the development of atherogenesis. Investigators in 1997, in the Journal of Thrombosis and Vascular Biology (United States), indicate that vitamin E has an "inhibitory effect" on LDL-induced production of adhesion molecules and adhesion of blood cell to ECs via its antioxidant function and/or its direct regulatory effect on cell adhesion and arteriosclerosis.
The elderly may receive extra value from vitamin E supplementation, as supplementation with 100 IU vitamin E in the elderly has been reported as beneficial in lowering the rate of oxidation of LDL, slowing the progression of atherosclerosis (Atherosclerosis, Sept. 1997, 133:255-63).
Smokers may benefit from long-term vitamin E supplementation, as it has been reported to improve endothelium-dependent relaxation in forearm resistance in vessels of hypercholesterolemic smokers which are characterized by increased levels of auto-antibodies against oxidized LDL. These findings suggest the beneficial effect of vitamin E for subjects with increased exposure to oxidized LDL such as smokers.
Soy: The FDA has approved soy as a method of lowering the risk of coronary heart disease. Soy has been a staple part of the Southeastern diet for nearly 5,000 years and is associated with a reduction in the rates of cardiovascular disease, and certain types of cancer. The research is now showing that phyto-chemicals in soy are the mechanism of action responsible.
Diets rich in soy protein can protect against the development of atherosclerosis. The mechanisms of action of soy protein include cholesterol lowering, inhibition of LDL oxidation, protection against the development of atherosclerosis, and reduction in risk of thrombosis. The active constituents in soy responsible for these benefits are the isoflavones genistein, daidzein, and glycitein. In a study to determine whether soy isoflavones would protect against atherosclerosis in mice, it was reported that mice fed a soy diet averaged 30% lower cholesterol.
Reducing saturated fat is the single most important dietary change you can make to cut blood cholesterol. Used as a replacement for meat and cheese, soy foods help your heart by slashing the amount of saturated fat that you eat.
Why is saturated fat so bad for your heart? The liver uses saturated fat to make cholesterol, so eating foods with too much saturated fat can increase cholesterol levels, especially low-density lipoproteins (LDL)---the bad cholesterol. Saturated fats are usually found in animal products such as whole milk, cream, butter, and cheese, and meats, such as beef, lamb and pork. There are some plant-based saturated fats you should avoid too, notably palm kernel oil, coconut oil, and vegetable shortening. Beyond replacing saturated fat, research suggests that compounds in soy foods called isoflavones may also work to reduce LDL cholesterol.
Soy products help to control the cholesterol level because: soy is cholesterol-free, the soy proteins reduce the cholesterol level, most of the fats in soy products are poly-unsaturated, soy isoflavones prevent atherosclerosis, soy contains soluble fibers which reduces the amount of cholesterol circulating in the blood. It is known that in countries were traditional soy products are consumed daily, the rates of cardiovascular diseases are low. There is some research that suggests that soy foods may help to prevent heart disease by reducing total cholesterol, low density lipoprotein cholesterol, blood pressure and possibly preventing plaque build-up in the arteries (atherosclerosis). Before the age of 60, man have more problems than women with their cholesterol levels. After menopause, when the production of natural estrogens drops, cholesterol levels in women will go up and the women become more suseptible to heart attacks. The soy isoflavones have a weak estrogen actity which is large enough to help reduce the cholesterol levels.
Postmenopausal women may also benefit from intake of soy protein, and it is suggested to be beneficial by researchers in a 1998 issue of American Journal of Clinical Nutrition for diseases and the risk factors (cholesterol) associated with cardiovascular disease.