Garlic for a healthier heart

In Western cultures, garlic is used for the prevention of or in the treatment of disease conditions, such as high blood pressure, atherosclerosis and high cholesterol, all more prevalent in industrialized, developed societies.

If one herb is both a culinary favorite and a medicinal treasure chest unto itself, it is garlic, Allium sativum. Garlic is known the world over as both food and medicine, a position it has occupied in human life for over 5,000 years.

Modern use of garlic is often determined by cultural perspective. In China, for example, garlic is called da-suan. While known as an edible plant since before recorded history, the first record of garlic's medicinal use in China appears in Tao Hongjing's Ming Yi Bei Lu (Miscellaneous Records of Famous Physicians), published during the era of the North and South Dynasties, around 91,0 A.D.

In modern China, garlic is considered a folk remedy, used by much, of the population, rather than an official drug" plant. However, the use of garlic has remained essentially the same over the centuries, as it is one of the best known treatments for dysentery caused by bacteria or other microorganisms. in Thailand, the bulbs are often used as a first line of treatment for skin diseases, as well as for cough, lung abscesses and other related conditions. In India, garlic is considered a powerful, natural disinfectant and internal cleansing herb. It is used as an antibacterial in intestinal disorders, as well as for a number of infectious diseases.

Garlic therapy has even been used in the treatment of leprosy. In developing countries around the world, it is clear that garlic is used for serious disease conditions, that would be treated with conventional drugs in Western medicine.

In Western cultures, garlic is used for the prevention of or in the treatment of disease conditions more prevelant in industrialized, developed societies. It is valued for its hypocholesterolemic (cholesterol-lowering) effect and for its antiatherosclerotic vascular plaque-fighting) effects, along with antiplatelet aggregation (anti-blood clumping), blood thinning and fibrinolytic (clot-dissolving) activities.

A biological overview of our arteries and their cells

Our inner arterial walls are composed of two types of cells. One type, called atherophils, is capable of accumulating fat. Atherophils will absorb fat when various factors are present, such as high cholesterol, high blood pressure or abnormal permeability of veins. Once the fat begins to collect, it can spread to neighboring cells and may cause cellular degeneration as it continues to accumulate. This process begins to consume high amounts of oxygen, increasing metabolism at the site. The changes take place where collagen fibers are produced by fibrocytes.

Other compounds, such as mucopolysaccharides, begin to build at the collagen fibers, causing the inner lining of the veins to thicken. As the process builds over time, atherosclerotic plaque builds in the cell walls, then extends to the muscle tissue on the middle layer of the vein or artery.

Consequently, the blood in the veins is slowed down. The ultimate result can be blockage, where the plaque breaks off and causes clotting.

Numerous studies, involving both animals and humans, have demonstrated the ability of garlic preparations to inhibit adhesion and aggregation, which then results in decreased risk to factors leading to hardening of the arteries. Garlic's ability to inhibit platelet aggregation has been shown to be influenced by the utilization of arachidonic acid, an unsaturated.

A number of compounds in a variety of different garlic preparations, including methyl-allyltrisulfide, dialyltrisulfide, allicin and ajoene have all been shown to be involved in antithrombotic (antistroke) and anti-blood-clumping activities, resulting in blood moving more freely in blood vessels. Garlic's ability to lower blood sugar levels, while increasing the concentration of glycogen (carbohydrate reserve) and free fatty acids in the liver, has also been shown to contribute to garlic's multi-faceted biological activity.

Garlic's effects on cholesterol -- a major area of study

One of the major areas in which garlic preparations have been studied in human clinical trials is its effect on cholesterol and low-density lipoprotein cholesterol (LDL, the "bad" kind). A recent review by German phytomedicine specialist, H.D. Reuter, in Cologne, summarizes the results of 28 clinical studies.

These studies were evaluated using various factors, including their initial design, number of patients involved, duration of treatment, types of garlic preparations used, dosages and tested effects. In these wide range of studies, with treatment durations lasting from several weeks to several months, when considered collectively, the garlic preparations showed a mean decrease in cholesterol levels of 10.3 percent.

The studies included both placebo-controlled and open studies. Various groups of patients were involved, including healthy people, those with hyperlipidemia, patients with hypercholesterolemia, those suffering from hypertension, coronary heart disease, arterial occlusive disease, and others.

Dosage forms involved fresh garlic, garlic powders and garlic oils. A number of lipid-regulating effects were measured, including a decrease of total cholesterol, increase of high-density lipoprotein cholesterol (so-called "good" cholesterol), inhibition of LDL, decreases in triglycerides, and an increase of apolipoprotein A, which is thought to be beneficial.

In the various studies, a number of indicators of garlic's effects on fibrinolysis and blood platelets were measured, including an increase in fibrinolytic activity, decrease of blood-plasma viscosity (stickiness), inhibition of platelet aggregation (clumping), suppression of connective-tissue-caused aggregation, and a decrease on spontaneous aggregation, among others.

Over two dozen clinical studies have evaluated the effect of garlic preparations on triglyceride levels. While there is greater variation in effects on triglycerides compared with studies on cholesterol levels, when evaluated collectively, clinical studies show an overall decrease in triglycerides of 14.3 percent. (Some clinicians regard high triglyceride levels as more dangerous than elevated cholesterol.

Garlic lowers blood pressure

A number of animal studies have shown the blood pressure-lowering effects of garlic preparations. The primary mechanism of action seems to be related to vasodilation (stimulation of blood vessels and widening of vessel's blood pathway). In one human study, a drop in blood pressure was seen in healthy subjects six hours after ingestion of a garlic preparation. The same effect was not observed in those volunteers who were not given the garlic supplementation.

In evaluating eight studies on the blood pressure-lowering effects of garlic, Reuter reported that treatment from one to six months decreased blood pressure by seven to nine percent. Patients with normal blood pressure failed to respond to garlic, while those with high blood pressure levels at the beginning of the studies experienced the greatest benefit.

Garlic is an antithrombotic and antiatherosclerotic agent

At proper dosage forms, it is reasonable to expect that garlic is useful as an antithrombotic (antistroke) and antiatherosclerotic vascular plaque-fighting) agent in western societies. The monograph produced by the Commission E of the German Federal Health Agency allows quality garlic preparations to be used as a dietary supplement to help control elevated blood lipids.

Garlic preparations also provide a preventive effect for age-related changes in the vascular system. According to the German health authorities, the daily dose of fresh garlic is calculated at 4 g of fresh garlic; phytomedicinal (plant-medicine) preparations correspond to the doses.

The German garlic monograph is now eight years old. According to Reuter, at that time, there was no standardization of garlic, based on the information that is available today. The basis for development of the phytomedicine Commission E monograph to bring quality medicinal products to the market must include pharmaceutical quality, clinical efficacy and safety.

He concludes that, based on the results of clinical and pharmacological studies done since 1988, a lipidlowering effect from garlic can be expected at a daily dose of about goo mg of powdered garlic.

Garlic has an extremely complex chemistry, with well over 160 compounds identified from the bulbs and the essential oil of garlic. Garlic's most noted effects Some of its noted effects include antioxidative and free-radical scavenging activity, lowering of blood pressure and increasing vascular resistance, blood-thinning activity, hypoglyremic effects, antifungal, antibacterial and antiviral effects, antimutagenic activity and hormonal effects, to name a few.

RELATED ARTICLE: What Garlic Can Do for You

Clinical studies show that garlic has these health-giving benefits:

Antibacterial Antiviral Antifungal Antiparasitic Antitumor Antioxidative Fights ear infections Decreases total and LDL cholesterol levels Decreases triglyceride levels Decreases HDL cholesterol levels Lowers blood pressure Decreases platelet aggregation (clumping) Prevents thrombosis (stroke) Increases insulin availability for diabetics Immunostimulant

SOURCE: Ralph Golan, M.D. Optimal Wellness. New York: Ballantine Books, 1995, p. 452.

REFERENCES

Farnsworth, N.R., and Bunyapraphatsara, N., editors. Thai Medicinal Plants Recommended for Primary Health Care System. Distributed in the U.S. by the American Botanical Council, Austin, Texas,1992.

Foster, S., and Yue, C.H. Herbal Emissaries Bringing Chinese Herbs to the West. Rochester, Vt.: Healing Arts Press,1992.

Reuter, H.D. "Allium Sativum and Allium Ursinum: Part 2. Pharmacology and Medicinal Application," Phytomedicine 2(l):73-91,1995.

Steven Foster is a specialist in medicinal and aromatic plants. He is the author of eight books, including Encyclopedia of Common Natural Ingredients, Used in Food, Drugs and Cosmetics (with Albert Leung,, John Wiley Sons 1995), and over 500 articles. Foster is a noted botanical photographer and serves as a consultant to the medicinal plant industries.

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