Comment: another good article from World's Healthiest Foods
Garlic
Although garlic may not always bring good luck, protect against evil or ward off vampires, it is guaranteed to transform any meal into a bold, aromatic and healthy culinary experience.
Fresh, dried and powdered garlic are available in markets throughout the year, however, fresh varieties from California are in season from June through December.
Garlic is arranged in a head, called the "bulb," averaging about 2 inches in height and diameter consisting of numerous small separate cloves. Both the cloves and the entire bulb are encased in paper-like sheathes that can be white, off-white or pinkish. Although garlic cloves have a firm texture, they can be easily cut or crushed. The taste of garlic is like no other-it hits the palate with a hot pungency that is shadowed by a very subtle background sweetness. While elephant garlic has larger cloves, it is more closely related to the leek and therefore does not offer the full health benefits of regular garlic.
- Health Benefits
- Description
- History
- How to Select and Store
- How to Enjoy
- Safety
- Nutritional Profile
- References
Whole books have been written about garlic, an herb affectionately called "the stinking rose" in light of its numerous therapeutic benefits. A member of the lily or Allium family, which also includes onions, garlic is rich in a variety of powerful sulfur-containing compounds including thiosulfinates (of which the best known compound is allicin), sulfoxides (among which the best known compound is alliin), and dithiins (in which the most researched compound is ajoene). While these compounds are responsible for garlic's characteristically pungent odor, they are also the source of many of its health-promoting effects. In addition, garlic is an excellent source of manganese, a very good source of vitamin B6 and vitamin C and a good source of selenium.
Cardiovascular Benefits
Numerous studies have demonstrated potential benefits of regular garlic consumption on blood pressure, platelet aggregation, serum triglyceride level, and cholesterol levels. Routine eating of garlic may also help stimulate the production of nitric oxide in the lining of blood vessel walls, which may help to relax them. As a result of these beneficial actions, garlic can be described as a food that may help prevent atherosclerosis and diabetic heart disease, as well as reducing the risk of heart attack or stroke. However, exactly which individuals are most benefitted from garlic consumption remains a matter of some debate. A study published in the Archives of Internal Medicine showed that garlic did not help lower LDL cholesterol in adults with moderately high (versus very high) levels when consumed at approximately one clove per day, six days per week, for 6 months. However, these researchers simulateously concluded that garlic might still have cardiovascular benefits for these same individuals, even though it did not help lower their LDL levels. While more large-scale research studies are needed to determine the exact nature of garlic's benefits, this food can definitely be considered a potential ally in heart health. A study published in Preventive Medicine shows that garlic inhibits coronary artery calcification, a process that serves as a marker for plaque formation since the body lays down calcium in areas that have been damaged. In this year-long study, patients given aged garlic extract daily showed an average increase in their calcium score of 7.5%, while those in the placebo group had an average increase in calcium score of 22.2%. One reason for garlic's beneficial effects may be its ability to lessen the amount of free radicals present in the bloodstream. According to a study published in Life Sciences, a daily dose of 1 ml/kg body weight of garlic extract for six months resulted in a significant reduction in oxidant (free radical) stress in the blood of patients with atherosclerosis. Since atherosclerotic plaques develop when cholesterol circulating in the bloodstream is damaged or oxidized, garlic's ability to prevent these oxidation reactions may explain some of its beneficial effects in atherosclerotic cardiovascular diseases. A German study published in Toxicology Letters indicates that garlic also greatly reduces plaque deposition and size by preventing the formation of the initial complex that develops into an atherosclerotic plaque. Called "nanoplaque," it is formed when calcium binds to proteoheparan sulfate and then to LDL cholesterol. Garlic prevents the binding of calcium to proteoheparan sulfate, thus decisively inhibiting plaque generation. Research presented at the 6th Annual Conference on Arteriosclerosis, Thrombosis and Vascular Biology held by the American Heart Association in Washington, D.C., suggests that garlic can help prevent and potentially reverse atherosclerotic plaque formation. The laboratory studies, conducted by well-known German scientist Professor Güautnter Siegel, M.D., from the University of Medicine in Berlin, Germany, found that powdered garlic (Kwai ® garlic) reduced the formation of nanoplaque (the first building blocks of atherosclerotic plaque) by up to 40% and reduced the size of the nanoplaque that did form by up to 20%. Dr. Siegel's research shows that garlic acts in a manner similar to HDL ("good") cholesterol, which prevents the build-up of nanoplaques by hindering the docking of LDL ("bad" cholesterol) to its receptor sites in blood vessels or existing plaques. Both garlic and HDL were able to reduce plaque formation and size within 30 minutes of incubation in these experiments. Existing plaques were dissolved by up to 25% within 15 minutes after the garlic was introduced, indicating a reversal of existing problems related to build-up of arterial plaque. In addition, calcification of the cholesterol docking sites in the arteries was reduced by up to 50% in the presence of the garlic extracts. New Research More Fully Explains Garlic's Cardiovascular Benefits Laboratory research by US and Swedish scientists published in the August 2005 Proceedings of the National Academy of Sciences reveals the mechanism behind garlic's cardiovascular benefits. The compounds in garlic responsible for its pungency also excite a neuron pathway providing cardiovascular benefits. Garlic's pungency-and that of the other members of the Alliumgenus of plants, such as onions, leeks and chives-results from its organosulphur compounds, allicin and diallyl disulphide (DADS). In this current in vitro study, allicin and DADS were found to activate perivascular sensory nerve endings, inducing the relaxation and enlargement of blood vessels, lowering blood pressure and improving blood flow throughout the body.
Garlic's numerous beneficial cardiovascular effects are due to not only its sulfur compounds, but also to its vitamin C, vitamin B6, selenium and manganese:
Garlic is a very good source of vitamin C, the body's primary antioxidant defender in all aqueous (water-soluble) areas, such as the bloodstream, where it protects LDL cholesterol from oxidation. Since it is the oxidized form of LDL cholesterol that initiates damage to blood vessel walls, reducing levels of oxidizing free radicals in the bloodstream can have a profound effect on preventing cardiovascular disease.
Garlic's vitamin B6 helps prevent heart disease via another mechanism: lowering levels of homocysteine. An intermediate product of an important cellular biochemical process called the methylation cycle, homocysteine can directly damage blood vessel walls.
The selenium in garlic not only helps prevent heart disease, but also provides protection against cancer and heavy metal toxicity. A cofactor of glutathione peroxidase (one of the body's most important internally produced antioxidants), selenium also works with vitamin E in a number of vital antioxidant systems. Since vitamin E is one of the body's top defenders in all fat-soluble areas, while vitamin C protects the water-soluble areas, garlic, which contains both nutrients, does a good job of covering all the bases. Garlic is rich not only in selenium, but also in another trace mineral, manganese, which also functions as a cofactor in a number of other important antioxidant defense enzymes, for example, superoxide dismutase. Studies have found that in adults deficient in manganese, the level of HDL (the "good form" of cholesterol) is decreased.
Practical Tip: National Health and Medical Research Council (NHMRC) Level III-3 evidence shows that consuming a half to one clove of garlic daily may have a cholesterol-lowering effect of up to 9%.(Tapsell LC, Hemphill I, et al. Med J Aust)
Anti-Inflammatory, Antibacterial and Antiviral Activity
Garlic, like onions, contains compounds that inhibit lipoxygenase and cyclooxygenase, (the enzymes that generate inflammatory prostaglandins and thromboxanes), thus markedly reducing inflammation. These anti-inflammatory compounds along with the vitamin C in garlic, especially fresh garlic, make it useful for helping to protect against severe attacks in some cases of asthma and may also help reduce the pain and inflammation of osteoarthritis and rheumatoid arthritis.
In addition, allicin, one of the sulfur-compounds responsible for garlic's characteristic odor, is a powerful antibacterial and antiviral agent that joins forces with vitamin C to help kill harmful microbes. In research studies, allicin has been shown to be effective not only against common infections like colds, flu, stomach viruses, and Candida yeast, but also against powerful pathogenic microbes including tuberculosis and botulism. Although garlic alone appears unable to prevent infection with Helicobacter pylori (H. pylori), the bacterium responsible for most peptic ulcers, as well as gastritis, frequently eating this richly flavored bulb may keep H. pylori from doing much damage. A study recently conducted at Faith University in Istanbul, Turkey, compared two groups of healthy individuals: one was selected from individuals who regularly ate lots of raw and/or cooked garlic, while the other group was composed of individuals who avoided it. For 19 months, blood samples were regularly collected from both groups and evaluated for the presence of H.pylori. While the incidence of H.pylori was pretty comparable-the bacterium was found in 79% of garlic eaters and 81% of those who avoided garlic-the garlic-consuming group had a clear advantage in that antibodies to H.pylori were much lower in their blood compared to those who ate no garlic. (Antibodies are formed when the immune system reacts to anything it considers a potential pathogen, so less antibodies to H.pylori means less of the bacterium was present.) Among those who ate garlic, those who ate both raw and cooked garlic had even lower levels of antibodies than those who ate their garlic only raw or only cooked. NF kappa-B is itself activated as part of the immune system's inflammatory response to invading organisms and damaged tissue. So, anything that sets off an inflammatory response (e.g. allergenic foods, a cold or other infection, physical trauma, excessive exercise, excessive consumption of foods containing high levels of omega-6 fatty acids-such as meat, corn or safflower oil) can trigger a surge in NF kappa-B, which in turn not only promotes inflammation but sets up ideal conditions for viruses, including HIV, to replicate. In the blood samples tested in these German studies, unfertilized garlic caused a 25% drop in NF kappa-B activity, while sulfur-fertilized garlic lowered NF kappa-B activity by a very robust 41%! Garlic and Onions Protective against Many Cancers Results of two studies suggest that garlic is a potent antibiotic, even against strains that have become resistant to many drugs. One study conducted at the University of California Irvine Medical Center and published in the December 2003 issue of Nutrition showed that garlic juice, even when diluted up to 1:128 of the original juice, demonstrates significant antibacterial activity against a spectrum of pathogens including antibiotic-resistant strains such as methicillin- and ciprofloxacin-resistant staphylococci, vancomycin-resistant enterococci, and ciprofloxacin-resistant Pseudomonas aeruginosa. A second study found that garlic was able to inhibit methicillin-resistant Staphylococcus aureus (MSRA) from human patients that was injected into laboratory animals.(MSRA is one of the antibiotic resistant bacteria whose incidence has risen dramatically in recent years in hospitals.)
Study participants consuming the most garlic had a 39% reduced risk for cancer of the oral cavity and pharynx, 57% reduced risk for esophageal cancer, 26% reduced risk for colorectal cancer, 44% reduced risk for laryngeal cancer, 10% reduced risk for breast cancer, 22% reduced risk for ovarian cancer, 19% reduced risk for prostate cancer, and 31% reduced risk for renal cell cancer, compared to those eating the least garlic.
Similarly, those eating the most onions showed an 84% reduced risk for cancer of the oral cavity and pharynx, 88% reduced risk for esophageal cancer, 56% reduced risk for colorectal cancer, 83% reduced risk for laryngeal cancer, 25% reduced risk for breast cancer, 73% reduced risk for ovarian cancer, 71% reduced risk for prostate cancer, and 38% reduced risk for renal cell cancer, compared to those eating the least onions.
Potent, Even Against Drug-Resistant Strains of Bacteria
Promotes Optimal Health
The organosulfur compound found in garlic called ajoene may also be useful in the treatment of skin cancer. In a study published in the July 2003 Archives of Dermatological Research, researchers applied ajoene topically to the tumors of patients with either nodular or superficial basal cell carcinoma, and in 17 of the 21 patients, the tumors shrunk significantly. Lab tests of the tumors before and after the application of ajoene revealed a significant decrease in Bcl-2, an apoptosis-suppressing protein. (Apoptosis is the self-destruct sequence used by the body to eliminate cancerous cells.)Other studies have shown that as few as two or more servings of garlic a week may help protect against colon cancer. Substances found in garlic, such as allicin, have been shown to not only protect colon cells from the toxic effects of cancer-causing chemicals, but also to stop the growth of cancer cells once they develop. While more research is needed to confirm, recent animal research has also suggested that garlic may confer protection against the development of stomach cancer through its potential ability to decrease H.pylori-induced gastritits.
Cooking garlic with meat appears to reduce the production of carcinogenic (cancer-causing) chemicals that can occur in meat as a result of cooking methods, such as grilling, that expose meat to high temperatures. Research presented at the American Association for Cancer Research's Frontiers in Cancer Prevention Research meeting in Baltimore, MD, suggests that the phytonutrient responsible for garlic's pungency may help prevent cancer by inhibiting the effects of one such carcinogen called PhIP. A cancer-causing heterocyclic amine, PhIP is thought to be one reason for the increased incidence of breast cancer among women who eat large quantities of meat because it is rapidly transformed into DNA-damaging compounds. Diallyl sulphide (DAS), an organosulfur compound that gives garlic its unique flavor, has been shown to inhibit the transformation of PhIP into carcinogens. DAS blocks this transformation by decreasing the production of the liver enzymes (the Phase I enzymes CYP1A1, CYP1A2 and CYP1B1) that transform PhIP into activated DNA-damaging compounds. In addition, DAS signals the genes responsible for producing two protective antioxidant enzymes, (glutathione-S-transferase (GST) and superoxide dismutase (SOD), which help protect the body against harmful compounds such as those produced from PhIP. These findings suggest that making garlic, onion, chives and other Allium vegetables, all of which contain DAS, a staple part of your Healthiest Way of Eating may help in preventing breast cancer induced by PhIP in well-done meats. And enjoying these DAS-rich foods may help protect the men you love as well: Consumption of Allium vegetables has also been associated with a reduced risk of prostate cancer.
Good intakes of vitamin C and selenium, with which fresh garlic is well-endowed, are also associated with a reduced risk of colon cancer, making garlic a smart addition to any colon cancer prevention plan. Cardiovascular disease is a well-known side-effect of diabetes, but garlic may provide some protection. When diabetic laboratory animals were given garlic extract for an 8-week period, the hyperreactivity of their blood vessels to noradrenaline (a vasoconstrictive hormone) and acetylcholine (a compound involved in nerve transmission) was significantly lessened. According to the researchers, their results suggest that garlic may help prevent the development of abnormal vascular contraction seen in diabetics. Promotes Weight Control Protection against Asbestos
For a small vegetable, garlic (Allium sativum) sure has a big, and well deserved, reputation. This member of the Lily family, a cousin to onions, leeks and chives, can transform any meal into a bold, aromatic and healthy culinary experience.
Garlic is arranged in a head, called the "bulb," which is made up of separate cloves. Both the cloves and the entire bulb are encased in paper-like sheathes that can be white, off-white or pinkish.
Garlic cloves are off-white in color, and although they have a firm texture, they can be easily cut or crushed. The taste of garlic is like no other; it hits the palate with a hot pungency that is shadowed by a very subtle background sweetness.
The teardrop-shaped garlic bulbs range in size; however, they usually average around two inches in height and two inches in width at their widest point. While elephant garlic has larger cloves, it is more closely related to the leek and therefore does not offer the full health benefits of regular garlic.
Native to central Asia, garlic is one of the oldest cultivated plants in the world and has been grown for over 5000 years. Ancient Egyptians seem to have been the first to cultivate this plant that played an important role in their culture.
Garlic was not only bestowed with sacred qualities and placed in the tomb of Pharaohs, but it was given to the slaves that built the Pyramids to enhance their endurance and strength. This strength-enhancing quality was also honored by the ancient Greeks and Romans, civilizations whose athletes ate garlic before sporting events and whose soldiers consumed it before going off to war.
Garlic was introduced into various regions throughout the globe by migrating cultural tribes and explorers. By the 6th century BC, garlic was known in both China and India, the latter country using it for therapeutic purposes.
Throughout the millennia, garlic has been a beloved plant in many cultures for both its culinary and medicinal properties. Over the last few years, it has gained unprecedented popularity since researchers have been scientifically validating its numerous health benefits.
Currently, China, South Korea, India, Spain and the United States are among the top commercial producers of garlic.
For maximum flavor and nutritional benefits, always purchase fresh garlic. Although garlic in flake, powder or paste form may be more convenient, you will derive less culinary and health benefits from these forms.
Purchase garlic that is plump and has unbroken skin. Gently squeeze the garlic bulb between your fingers to check that it feels firm and is not damp.
Avoid garlic that is soft, shriveled and moldy or that has begun to sprout. These may be indications of decay that will cause inferior flavor and texture. Size is often not an indication of quality. If your recipe calls for a large amount of garlic, remember that it is always easier to peel and chop a few larger cloves than many smaller ones. Fresh garlic is available in the market throughout the year.
Store fresh garlic in either an uncovered or a loosely covered container in a cool, dark place away from exposure to heat and sunlight. This will help maintain its maximum freshness and help prevent sprouting, which reduces its flavor and causes excess waste. It is not necessary to refrigerate garlic. Some people freeze peeled garlic; however, this process reduces its flavor profile and changes its texture.
Depending upon its age and variety, whole garlic bulbs will keep fresh from two weeks to two months. Inspect the bulb frequently and remove any cloves that appear to be dried out or moldy. Once you break the head of garlic, it greatly reduces its shelf life to just a few days.
Tips for Preparing Garlic:
The first step to using garlic (unless you are roasting the entire bulb) is to separate the individual cloves. An easy way to do this is to place the bulb on a cutting board or hard surface and gently, but firmly, apply pressure with the palm of your hand at an angle. This will cause the layers of skin that hold the bulb together to separate.
To separate the skin from the individual cloves, place a clove with the smooth side down on a cutting board and gently tap it with the flat side of a wide knife. You can then remove the skin either with your fingers or with a small knife. If there is a green sprout in the clove's center, gently remove it since it is difficult to digest.
Chopping or crushing stimulates the enzymatic process that converts the phytonutrient alliin into allicin, a compound to which many of garlic's health benefits are attributed. In order to allow for maximal allicin production, wait several minutes before eating or cooking the garlic.
A Few Quick Serving Ideas:
Marinate pressed garlic in olive oil and use this flavored oil in dressings and marinades.
Purée fresh garlic, canned garbanzo beans, tahini, olive oil and lemon juice to make quick and easy hummus dip.
Healthy sauté steamed spinach, garlic, and fresh lemon juice.
Add garlic to sauces and soups.
Purée roasted garlic, cooked potatoes and olive oil together to make delicious garlic mashed potatoes. Season to taste.
Garlic is not a commonly allergenic food, is not known to contain measurable amounts of goitrogens, oxalates, or purines, and is also not included in the Environmental Working Group's 2006 report "Shopper's Guide to Pesticides in Produce" as one of the 12 foods most frequently containing pesticide residues.
Do not store garlic in oil at room temperature. Garlic-in-oil mixtures stored at room temperature provide perfect conditions for producing botulism, regardless of whether the garlic is fresh or has been roasted.
Garlic is an excellent source of manganese. . It is also a very good source of vitamin B6 and vitamin C. and . In addition, garlic is a good source of protein and thiamin (vitamin B1) as well as the minerals phosphorous, selenium, calcium, potassium, iron and copper.
For an in-depth nutritional profile click here: Garlic.
In-Depth Nutritional Profile
In addition to the nutrients highlighted in our ratings chart, an in-depth nutritional profile for Garlic is also available. This profile includes information on a full array of nutrients, including carbohydrates, sugar, soluble and insoluble fiber, sodium, vitamins, minerals, fatty acids, amino acids and more.Introduction to Food Rating System Chart
The following chart shows the nutrients for which this food is either an excellent, very good or good source. Next to the nutrient name you will find the following information: the amount of the nutrient that is included in the noted serving of this food; the %Daily Value (DV) that that amount represents; the nutrient density rating; and the food's World's Healthiest Foods Rating. Underneath the chart is a table that summarizes how the ratings were devised. Read detailed information on our Food and Recipe Rating System.
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No comments:
Post a Comment