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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 July through December.
Garlic is arranged in a head, called the “bulb,” averaging
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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
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
that regular consumption of garlic lowers blood pressure, and decreases
platelet aggregation, serum triglycerides and LDL-cholesterol (the
potentially dangerous form) levels while increasing serum
HDL-cholesterol (the protective form) and fibrinolysis (the process
through which the body breaks up blood clots), and stimulating the
production of nitric oxide in the lining of blood vessel walls, which
helps them to relax. As a result of these beneficial actions, garlic
helps prevent atherosclerosis and diabetic heart disease, and reduces
the risk of heart attack or stroke.
A study published in the November 2004 issue of Preventive
Medicine
shows that garlic also 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 the September 2004 issue of 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 November 2004 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.
Garlic's numerous beneficial cardiovascular effects are due to
not
only its sulfur compounds, but 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-solouble)
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 vitmain 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.
Anti-Inflammatory, Anti-Bacterial and Anti-Viral 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. 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, the
bacterium responsible for most peptic ulcers, 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 containing 81 healthy
individuals each. One group 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.
Laboratory studies recently
conducted at the University of Munich, Germany, help explain why garlic
may be such a potent remedy against the common cold. In these studies,
garlic was found to significantly reduce the activity a chemical
mediator of inflammation called nuclear transcription factor (NF)
kappa-B.
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 (e.g., 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 just published 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%!
Potent, Even Against Drug-Resistant Strains
Results of two recently published 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 mice.(MSRA is one of
the antibiotic resistant bacteria whose incidence has risen
dramatically in recent years in hospitals.) Sixteen hours after the
mice were infected, garlic extract, diallyl sulphide or diallyl
disulphide (two of the active compounds found in garlic), was given
orally. Twenty-four hours after they were infected, the mice were
sacrificed and examined. Both garlic extract and its compounds were
found to have exerted a number of protective actions against MSRA that
significantly decreased the infection while also providing antioxidant
protection in the blood, liver, kidney and spleen.
Cancer Protection
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 abilty to decrease H.pylori-induced
gastritits.
Cooking garlic with meat appears to reduce the production of
carcinogenic chemicals that can occur in meat as a result of cooking
methods, such as grilling, that expose meat to high temperatures. 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.
Diabetes Mellitus
Garlic may be able to help protect against a number of the most
damaging degenerative effects of diabetes—retinopathy disease of the
retina), nephropathy (kidney disease) and neuropathy (nervous system
disease)—all of which are caused by an imbalance between the free
radicals generated when blood sugar levels remain high and the body’s
protective antioxidant defenses. A study published August 2003 showed
that when diabetic rats were exposed to the cancer drug,
streptozotocin, which would normally have produced not only a
significant rise in blood sugar levels, but an increase in
triglycerides, cholesterol, damaged fats, and other markers of
increased inflammation, along with a decrease in the antioxidants the
body produces to protect itself, that giving the rats garlic oil both
lowered the drug’s negative effects while boosting protective
antioxidant levels. The rats in this study were given 10 mg of garlic
oil per kilogram of body weight daily for 15 days. In humans, a
comparable dose of garlic oil would be .7 grams per day, an amount that
could be easily consumed if using a garlic oil product, but would take
real dedication if consuming cloves. Since a typical garlic clove
weighs 3 grams and contains 15mg of total fat, which we can treat as
basically synonymous with oil, this would translate to about 46 ½
cloves of garlic!
Protection Against Diabetes-Linked Cardiovascular Disease
Cardiovascular disease is a well-known side-effect of diabetes, but
garlic may provide some protection, according to a study published
December 2003. When diabetic rats 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.
Weight Control
The most potent active constituent in garlic, allicin, has been shown
to not only lower blood pressure, insulin and triglycerides in rats fed
a fructose (sugar)-rich diet, but also to prevent weight gain,
according to a study published in the December 2003 issue of the American
Journal of Hypertension.
In this study, after 5 weeks of being fed a high fructose diet
consisting of 21% protein, 5% fat, 60% carbohydrate, 0.49% sodium and
0,49% potassium, male rats had developed high insulin levels, high
blood pressure and high triglycerides. The rats were then divided into
3 groups for the remaining 5 weeks of the study: the first group served
as a control; the second was given allicin during the final 2 weeks of
the study, and the third was given allicin during the initial 3 weeks.
Despite the fact that all three groups consumed the same amount of
food, weight rose in the control group and in groups 2 and 3 when not
receiving allicin, but remained stable or declined slightly when
allicin was given. The researchers concluded that allicin may be of
practical value for weight control.
Increased Antioxidant Protection
A study published in the November 2003 E-version of the journal Carcinogenesis
showed that levels of a critically important internally produced
antioxidant enzyme, glutathione-S-transferase,
rose substantially in the stomach and small intestine, and to a lesser
extent in the liver and colon, in rats that were put on a short-term
feeding regimen that featured two compounds from garlic, diallyl
disulfide and diallylthiosulfinate (allicin). Researchers discovered
that these garlic compounds selectively induced two genes to produce
more of the messenger RNAs (mRNAs) that encode
glutathione-S-transferase, and the greatest increases were noted in
mRNAs that are normally present only at low levels. The bottom line:
eating more garlic may help increase your body’s production of this
vitally important antioxidant enzyme.
Protection against Asbestos
Asbestos, a well known carcinogen, is thought to cause cell mutations
by generating reactive oxygen species (free radicals) and depleting one
of the body's most important internally produced antioxidants,
glutathione. Garlic contains numerous sulfur compounds and glutathione
precursors that act as antioxidants and also demonstrate
anti-carcinogenic properties. In a laboratory study published in the
November 2004 issue of Toxicology Letters,
garlic extract, when administered along with asbestos, so significantly
reduced DNA mutations in human blood lymphocytes (a type of immune
cell), that the researchers concluded: "garlic extract may be an
efficient, physiologically tolerable quencher of asbestos-induced
genotoxcity."
Description
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.
History
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 in which athletes ate garlic before sporting
events, and 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.
How to Select and Store
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, 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.
How to Enjoy
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 phytochemical 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.
Safety
Garlic is not a commonly allergenic food, is not included in
the
list of 20 foods that most frequently contain pesticide residues, and
is also not known to contain goitrogens, oxalates, or purines.
Nutritional Profile
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 (similar to other information
presented in the website, this DV is calculated for 25-50 year old
healthy woman); 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.
Garlic
1.00 oz-wt
42.24 calories |
| Nutrient |
Amount |
DV
(%) |
Nutrient
Density |
World's Healthiest
Foods Rating |
| manganese |
0.47 mg |
23.5 |
10.0 |
excellent |
| vitamin B6 (pyridoxine) |
0.35 mg |
17.5 |
7.5 |
very good |
| vitamin C |
8.85 mg |
14.8 |
6.3 |
very good |
| tryptophan |
0.02 g |
6.3 |
2.7 |
good |
| selenium |
4.03 mcg |
5.8 |
2.5 |
good |
| calcium |
51.31 mg |
5.1 |
2.2 |
good |
| phosphorus |
43.38 mg |
4.3 |
1.8 |
good |
| copper |
0.08 mg |
4.0 |
1.7 |
good |
| vitamin B1 (thiamin) |
0.06 mg |
4.0 |
1.7 |
good |
| protein |
1.80 g |
3.6 |
1.5 |
good |
World's Healthiest
Foods Rating |
Rule |
| excellent |
DV>=75% |
OR |
Density>=7.6 |
AND |
DV>=10% |
| very good |
DV>=50% |
OR |
Density>=3.4 |
AND |
DV>=5% |
| good |
DV>=25% |
OR |
Density>=1.5 |
AND |
DV>=2.5% |
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References
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hormonal and
biochemical mechanisms and associations. Scand J Clin Lab Invest.
1990:50(S201):3-23.
- Andorfer JH, Tchaikovskaya T, Listowsky I. Selective
expression of glutathione S-transferase genes in the murine
gastrointestinal tract in response to dietary organosulfur compounds. Carcinogenesis
2003 Nov 21 [Epub ahead of print].
- Anwar MM, Meki AR. . Oxidative stress in
streptozotocin-induced diabetic rats: effects of garlic oil and
melatonin. Comp Biochem Physiol A Mol Integr Physiol.
Aug;135(4):539-547.
- Baluchnejadmojarad T, Roghani M. Endothelium-dependent and
-independent effect of aqueous extract of garlic on vascular reactivity
on diabetic rats. Fitoterapia. 2003 Dec;74(7-8):630-7.
- Bhattacharya K, Yadava S, Papp T, Schiffmann D, Rahman Q.
Reduction of chrysotile asbestos-induced genotoxicity in human
peripheral blood lymphocytes by garlic extract. Toxicol Lett.
2004 Nov 28;153(3):327-32.
- Durak I, Aytac B, Atmaca Y, Devrim E, Avci A, Erol C, Oral
D.
Effects of garlic extract consumption on plasma and erythrocyte
antioxidant parameters in atherosclerotic patients. Life Sci.
2004 Sep 3;75(16):1959-66.
- Elkayam A, Mirelman D, Peleg E, Wilchek M, Miron T,
Rabinkov
A, Oron-Herman M, Rosenthal T. The effects of allicin on weight in
fructose-induced hyperinsulinemic, hyperlipidemic, hypertensive rats. Am
J Hypertens. 2003 Dec;16(12):1053-6.
- Keiss HP, Dirsch VM, Hartung T, Haffner T, Trueman L, Auger
J, Kahane R, Vollmar AM. Garlic (Allium sativum L.)
modulates cytokine expression in lipopolysaccharide-activated human
blood thereby inhibiting NF-kappaB activity. J Nutr. Jul;133(7):2171-5.
- Lee YL, Cesario T, Wang Y, Shanbrom E, Thrupp L.
Antibacterial activity of vegetables and juices. Nutrition.
2003 Nov-Dec;19(11-12):994-6.
- Salih BA, Abasiyanik FM. Does regular garlic intake affect
the prevalence of Helicobacter pylori in asymptomatic subjects. Saudi
Med J. Aug;24(8):842-5.
- Siegel G, Michel F, Ploch M, Rodriguez M, Malmsten M.
[Inhibition of arteriosclerotic plaque development by garlic]. Wien
Med Wochenschr. 2004 Nov;154(21-22):515-22.
- Tilli CM, Stavast-Kooy AJ, Vuerstaek JD, Thissen MR,
Krekels
GA, Ramaekers FC, Neumann HA. The garlic-derived organosulfur component
ajoene decreases basal cell carcinoma tumor size by inducing apoptosis.
Arch Dermatol Res. Jul;295(3):117-23.
- Tsao SM, Hsu CC, Yin MC. Garlic extract and two diallyl
sulphides inhibit methicillin-resistant Staphylococcus aureus infection
in BALB/cA mice. J Antimicrob Chemother. 2003 Dec;52(6):974-80.
Dietary supplements cannot be used to prevent or treat any
disease. These statements have not been evaluated by the FDA.
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Dietary supplements are not to be used to
prevent
or treat any disease.
The Statements on this web page have not been evaluated by the FDA. Any
information provided on this website is not a substitute for the advice
of a licensed medical practitioner. Individuals are advised not to
self-medicate in the presence of significant illness. Ingredients in
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