Garlic is not just for jazzing up your pizza

Garlic is not just for jazzing up your pizza
Source: Victoria Dolby

For centuries, garlic has been used for a variety of reasons, ranging from adding zest to pizza to keeping away the "undead." In addition, Allium sativum is one of the oldest traditional medicinal plants. Today, a growing body of scientific evidence confirms the amazing disease-prevention and health-promotion qualities of garlic, particularly for ensuring a healthy heart.

When researchers compare countries with a pen chant for garlic to those that eschew the herb, they find that the garlic-lovers have a collectively lower incidence of heart disease. Two of the most important precursors of heart disease are cholesterol and blood pressure levels. Garlic is gaining a reputation for combating both of these heart disease markers.

In fact, just recently, researchers from East Carolina University confirmed that garlic supplements, after being given to a group of men at risk for heart disease, have the ability to slash both cholesterol and blood pressure. Manfred Steiner, M.D., Ph.D., the lead researcher of this study, gathered together 41 men with moderately-high cholesterol levels (220-290 mg/dL) and explained the benefits of the National Cholesterol Education

Step I diet. This cholesterol-lowering diet was continued throughout the entire study period. After using this diet for one month, half of the men were given daily garlic supplements, while the other half unknowingly received dummy pills. After six months of these supplements, the pills were switched, and the study continued for another four months.

Steiner noted in the American Journal of Clinical Nutrition: "Our double-blind crossover study showed that garlic supplementation can produce significant reductions in total as well as LDL cholesterol...[in addition,] blood pressure is beneficially affected by garlic administration."
More specifically, total cholesterol levels were 7 percent lower and low-density lipoprotein (LDL) cholesterol (the "bad" kind) was 4 percent lower after using the garlic supplements. It took about three months of supplementation before garlic reached its maximum effect on cholesterol levels.

Garlic is thought to reduce blood cholesterol levels in at least three ways:
1) by either inhibiting or cutting down the amount of cholesterol produced by the liver;
2) by increasing the metabolic breakdown and removal of cholesterol from the body; and
3) by encouraging the movement of stored cholesterol from the tissues to the bloodstream for excretion.

Steiner's study also showed a significant decrease in systolic blood pressure by 5.5 percent and a small, but notable, decrease in the diastolic level. Other researchers suggest that the blood pressure lowering effects of garlic result from the relaxation of the smooth muscles of the blood vessels.

Atherosclerosis, a condition characterized by fatty deposits accumulated inside the blood vessel walls, is another important marker of future risk of heart attack. Again, garlic shows promise in counteracting this condition.

Researchers from the Russian Academy of Medical Sciences in Moscow extracted blood vessel cells from humans with atherosclerosis and combined them with a garlic extract. These cultured cells, in the absence of garlic, would be expected to retain excessive levels of cholesterol.

However, the addition of garlic lowered cholesterol levels in the cells and blocked the build-up of plaque in the blood vessels.

In a related experiment, a group of heart disease patients with angina were supplemented with garlic. Blood from these patients was drawn before and after taking the supplement and added to the cultured blood vessel cells. The cells with the pre-supplement blood continued to develop signs of heart disease, while the post-supplement blood resulted in a remarkable slowing in the development of heart disease. From this, the researchers concluded that garlic may both treat and prevent atherosclerosis.

Eating plenty of garlic will certainly increase your intake of this medicinal herb, but that might not be the most convenient to your diet. Alternatives include the standardized and odor-controlled garlic extract supplements available in encapsulated form.


REFERENCES
Steiner, M., et al "A Double-blind Crossover Study in Moderately Hypercholesterolemic Men that Compared the Effect of Aged Garlic Extract and Placebo Administration on Blood Lipids," American Journal of Clinical Nutrition 64(6):866-870, December 1996.

Orekhov, A., et al. "Direct Anti-atherosclerosis-related Effects of Garlic," Annals of Medicine 27:63-65, 1995.