Garlic Benefits & Nutritional values

Garlic characteristics

  • Rich in antioxidants;
  • Source of sulfur compounds;
  • Promotes cardiovascular health;
  • Anti-cancer properties;
  • Rich in taste and low in calories.

 Nutritional and caloric values ​​of garlic

Consumed in small quantities, garlic provides few nutrients. On the other hand, consumed in larger quantities over the course of a day, garlic turns out to be a source of some nutrients. For example, a bulb of garlic (about 40 ml or 24 g of garlic) is a good source of manganese and vitamin B6, as well as a source of phosphorus (see our Factsheet of nutrients Phosphorus), iron , copper, selenium and vitamin C.

What is a “portion” of garlic worth?
Weight / volumeRaw garlic, 3 g / 1 clove
Protein0.2 g
Carbohydrates1.0 g
Lipids0.0 g
Dietary fiber0.1 g

Garlic contains many active compounds, which provide different health benefits. Some of these compounds are assigned several roles. This is the case, among others, of sulfur compounds, associated both with the prevention of cancer and cardiovascular disease. It should be noted that not all of garlic’s phytochemicals are active in the body and that some have yet to be discovered. Note that the active ingredients contained in fresh garlic work synergistically to produce different health effects. Among these active ingredients, we can cite:

  • Sulphide compounds. These substances are so named because they contain sulfur atom (s) in their chemical structure. Sulfur compounds are released when garlic is cut, crushed or crushed. At this point, alliin (an inactive, odorless molecule in garlic) comes into contact with an enzyme and turns into allicin, which is the molecule responsible for the characteristic smell of garlic. Subsequently, the allicin is transformed into other sulfur compounds such as diallyl sulfide, diallyl disulfide and ajoene. It is mainly these compounds that could prevent certain cancer cells from multiplying and thus protect the body against potential carcinogens. It should be noted that during the manufacture of garlic tablets, the allicin would be destroyed, so that the consumption of garlic tablets would not allow the ingestion of the active compounds beneficial to health;
  • Allicin has been proposed as the main active compound associated with the cardioprotective effect of garlic, among other things by its ability to reduce atherosclerotic plaques in animals. On the other hand, when one takes into account the fact that allicin is not absorbed into the blood during consumption of garlic, it is unlikely that it contributes as such to the effect on cardiovascular health. Allicin is rather a transient compound rapidly transformed into other sulfur compounds which, in turn, are active in the body. Finally, ajoene would be a compound capable of preventing the synthesis (formation) of cholesterol in vitro and could thus play a role in the hypocholesterolemic effect attributed to garlic;
  • Saponins are compounds present in garlic which have the capacity to decrease blood cholesterol in animals and blood clotting in vitro, two effects sought for the prevention of cardiovascular diseases. In addition, it has been shown in animals that the isolated garlic protein may have a lipid-lowering effect. These promising compounds could therefore be associated with the cardioprotective effect of garlic, but more studies will be needed to better understand their roles.

 The benefits of garlic

Garlic has been used for several hundred years to treat various health problems. A large number of studies have been carried out in order to better understand the active ingredients of garlic and their physiological effects. In these studies, garlic is used in different forms: fresh, dehydrated, as well as as an extract, oil or tincture. It should be noted that this sheet is only devoted to the effects of consuming fresh garlic (raw or cooked) as used in various food preparations.

Garlic, a protective ingredient against certain chronic pathologies 

Several prospective and epidemiological studies have shown that a high consumption of vegetables and fruits decreases the risk of cardiovascular diseases, certain cancers and other chronic diseases. More specifically, studies have shown that the consumption of vegetables from the alliaceae family (garlic, onion, shallot, chives, scallions, leek) would have a protective effect against cancers of the stomach and intestine. 

Garlic and cancers

Garlic may slow down the development of certain cancers, both through its protective action against damage caused by carcinogens and through its ability to prevent cancer cells from growing. The sulfur compounds contained in garlic could play an important role. Thus, garlic, at the rate of a consumption of two cloves per day (approximately 6 g of garlic), is part of a list of foods containing molecules with anticarcinogenic potential to be favored in an optimal diet aimed at prevent cancer.

The results of a meta-analysis of 18 epidemiological studies published between 1966 and 1999 demonstrate a 30% reduction in the risk of colorectal cancer and about 50% in the risk of stomach cancer in the event of high consumption of garlic. Among all the studies noted, such consumption was equivalent to approximately 18 g of raw and cooked garlic per week (or approximately six cloves). Since the amounts ingested varied greatly from study to study, it is difficult to determine more precisely the minimum amount of garlic to consume in order to benefit from its effects on colorectal and stomach cancers. In addition, it is important to remember that a food alone cannot be effective in protecting against cancer. A varied and constant consumption of several foods with preventive potential as well as the maintenance of a healthy lifestyle are essential elements.

Other studies have observed an inverse relationship between garlic consumption and the incidence of laryngeal, prostate and breast cancers. However, no general conclusion can be drawn for the moment, given the too few studies on the subject. To date, there is insufficient data to establish a link with other types of cancer such as cancer of the esophagus and lung.

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A true ally for cardiovascular health

The American Heart Association (AHA) publishes dietary recommendations that help prevent the risk of cardiovascular disease, such as eating high fruit and vegetables, as well as choosing whole-grain cereal products and low-fat dairy products. . Based on numerous research results, the AHA offers a list of specific foods with some cardioprotective effect. Garlic is one of these foods (along with nuts, soy, legumes and tea) and its consumption is therefore in addition to the basic recommendations of the AHA for the prevention of cardiovascular disease.

The majority of studies evaluating the effect of garlic on risk factors for cardiovascular disease (such as blood pressure, cholesterol and blood glucose) have been performed with garlic supplements or extracts, in order to isolate the active ingredients. Overall, this research shows a tendency to slightly lower blood cholesterol and triglyceride levels. Few studies have therefore evaluated the real impact of the consumption of fresh garlic (raw or cooked) on these risk factors and they date back a few years. In two of these studies, consuming 3 g and 10 g of fresh garlic daily for 16 and 8 weeks, respectively, contributed to a decrease in total cholesterol. Further studies will be needed to assess the effect of consuming fresh garlic on the prevention and treatment of cardiovascular disease. According to the results of studies using garlic extracts, a daily consumption equivalent to 2 g to 5 g of raw garlic or 10 g to 15 g of cooked garlic would be necessary in order to benefit from certain factors. risk of cardiovascular diseases such as total cholesterol, LDL cholesterol (“bad” cholesterol) or high triglycerides in the blood.

 Anti-microbial and anti-infectious properties?

Garlic is traditionally used for its antimicrobial properties and for the treatment of certain infections. The majority of studies on the subject have been carried out using garlic extracts, at doses that are often difficult to achieve with usual consumption of fresh garlic. In a study carried out in a population in a region of China, a high consumption of garlic (more than 5 kg per year per person, or the equivalent of about four to five cloves of garlic per day) was weakly associated with a decrease in infections with Helicobacter pylori bacteria. This observation was disputed by a clinical study in which people consumed ten fresh garlic cloves per day, with no significant effect against H. pylori infection.

 Some studies suggest that garlic may help prevent colds. Indeed, in one study, two groups were compared: one consumed a garlic supplement and the other a placebo for 12 weeks during the cold season (November to February). The results show that those who were in the group with the garlic supplement had fewer cold episodes than those who took a placebo. In addition, when they had a cold, the individuals who were in the group with the garlic supplement saw their symptoms decrease more quickly than those who took a placebo. For now, the data are still insufficient to confirm that the consumption of fresh garlic would bring an anti-infectious effect in the body.

An interesting antioxidant content

Antioxidants are compounds that protect cells in the body from damage caused by free radicals. These are very reactive molecules that are believed to be involved in the development of cardiovascular diseases, certain cancers and other diseases linked to aging. Garlic contains various antioxidant compounds such as flavonoids and tocopherols, in addition to sulfur compounds which would also contribute to its antioxidant activity. 

Consumption of fresh garlic (raw or cooked) is believed to increase antioxidant activity in plasma in rats, but daily consumption of 3 g to 6 g of raw garlic for seven to eight days in humans has not. confirmed this observation. We know all the same that at equivalent weight, garlic has a higher antioxidant capacity than a wide selection of vegetables. On the other hand, when the frequency and size of the portion usually consumed are taken into account, the impact of garlic consumption on the total antioxidant capacity remains limited, compared to other vegetables consumed in larger quantities.

A word from the nutritionist


The enzyme found in garlic that allows the formation of allicin and other sulfur compounds is deactivated by heat. Depending on how and how long the garlic is cooked, the sulfur compounds formed will be different and the amount of antioxidants may decrease. The properties of raw garlic would thus be superior to those of cooked garlic. A tip: add the garlic 20 minutes or less before the end of cooking to preserve the quality of its active compounds as much as possible.

 How to choose the right garlic?

Garlic is a perennial vegetable plant with a bulb with a strong smell and flavor. This characteristic taste has earned it to be considered one of the major condiments of French cuisine. The head of garlic is made up of several cloves that are very popular in cooking. There are several varieties of garlic, the most common being white garlic and purple garlic. 

Garlic identity card

  • Family: amaryllidaceae;
  • Origin: Central Asia;
  • Season: available all year round;
  • Color: white to red;
  • Flavor: powerful.

Soft-stemmed garlic or hard-stemmed garlic?

Garlic commonly sold in America is of the subspecies Allium sativum var. sativum, which is botanically characterized by the absence of a flower stalk (hence its name “tender-stemmed garlic”) and numerous small pods.

From a culinary point of view, the subspecies Allium sativum var. ophioscorodon, which has a floral stalk (hence its name “hard-stemmed garlic” or “stick garlic”) and fewer and relatively larger pods, is clearly superior. This subspecies is believed to be the older of the two and has retained some of the characteristics of wild garlic including its flavor and, unfortunately, its short shelf life. 

Preserved over the centuries thanks to the care of informed amateurs, stick garlic is offered today through networks of artisan producers as well as by a few specialized shops. In Europe, where it is better known, it is not uncommon for it to be considered a local product. This is the case with pink garlic from Lautrec which, in France, has a controlled designation of origin.

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Rocambole garlic 

This hard-stemmed type is particularly tasty, but not always easy to find.

False garlic 

What is called in Quebec “elephant garlic” and, in France, “oriental garlic” is not garlic, but a kind of leek that is generally prepared in the same way, although it has neither the strong flavor nor the virtues of garlic.

Storage of garlic 

Depending on the variety, fresh garlic can be kept for three to nine months. Keep it dry at room temperature, as cold and humidity have the effect of triggering the germination process.

 How to prepare garlic

In order to remove the peel from the garlic, it is crushed with the flat of a knife. The germ is then removed which would make the garlic indigestible and which would be largely responsible for bad breath. The garlic is then ready to be cooked and incorporated into various preparations. 

Preparation of the garlic

This is the name of the garlic shoot that comes out of the ground in spring and has not yet started to form its bulb. It is eaten in a croque-au-sel or lightly steamed and drizzled with a vinaigrette, as with leek. You can also mince it in salads, soups, etc. Look for this product in Asian grocery stores.

Cooking the flower stalk 

In order to promote the production of the bulb, the flower stalk of the garlic, with its flower bud, must be cut shortly after its formation. Finely chopped, it goes into all kinds of preparations, such as garlic butter. It can be found in a jar in delicatessens.

Garlic in shirt

Roasted or grilled in the oven in its skin, garlic acquires a very special flavor that will enhance mayonnaise, dressings or hot sauces. The whole bulb will first be topped and brushed with oil. You can also add the individual pods to a broth or sauce and remove them when ready to serve, or stuff a roasting poultry with them. At the end of cooking, we can collect the garlic and make a sauce.

Savor garlic as an aioli

The aioli is assembled like mayonnaise except that you start with crushed garlic before adding the usual ingredients. It can accompany fish, cold meat or fondue. If we add a piece of bread crumbs soaked in fish stock and Spanish red peppers, we obtain a rouille, traditionally served in Provence with bouillabaisse.

Discovering aïgo-bouïdo

Of the many garlic soup recipes developed around the world, one of the simplest is aïgo-bouïdo, with semi-culinary, semi-medicinal uses. To prepare it, cook six crushed garlic cloves in a liter of boiling water for about ten minutes. Then remove from heat, add sage, thyme and bay leaf and let infuse for a few minutes. Remove the herbs, beat an egg into an omelet and add it to the soup without stopping beating. Salt and pepper. This broth is served on a slice of bread drizzled with oil.

Use garlic to spice up the simplest dishes

fry whole garlic cloves in oil, then remove the garlic and coat the pasta with this fragrant oil. Others prefer to simply add crushed garlic to very hot noodles with a little melted butter or olive oil.

Garlic, a bitter rectifier in the kitchen

Dandelion, chicory, escarole, raddichio, Treviso lose some of their bitterness and are enhanced when served with croutons returned in olive oil and rubbed with garlic. Drizzle with hot dressing to soften the greens, and add bacon, if desired.

Homemade garlic butter, a very French delight

Serve frog legs, shrimps and snails topped with butter and kneaded with finely chopped garlic, shallots and parsley. Spend a few minutes in the oven over high heat. Mussels can be cooked in butter, with garlic, herbs and white wine, covering, until they open. Reduce the liquid to high heat and coat the mussels with it.

Bet on garlic bread for a simple pleasure 

To do this, cut a slightly stale baguette into slices without completely detaching the slices. Insert between the slices the butter handled with chopped garlic and salt. Enclose the baguette in aluminum foil, put in the oven over medium heat and cook for 20 or 30 minutes.

 Contraindications and allergies

The very high concentration of active molecules in garlic is a valuable asset, but with a double edge. Indeed, garlic contains substances that can interfere with certain medications or damage the gastrointestinal barrier in sensitive people, especially if consumed in large quantities. 

Interactions with certain drugs

Garlic extracts or supplements interact with certain drugs that thin the blood or have an anticoagulant effect. Likewise, consuming excessive amounts of fresh garlic while taking certain blood thinning medications could have an additive effect, thus increasing the risk of bleeding.

 In addition, it is advisable to avoid consuming garlic before surgery to decrease the risk of prolonged bleeding. Finally, in people taking hypoglycemic drugs, consuming large amounts of fresh garlic may increase the effect of these drugs. In general, the consumption of less than 4 g of garlic (the equivalent of a clove) per day seems prudent in order to avoid any harmful interactions.

Garlic preserved in oil and risk of botulism 

Garlic can be stored in oil, which helps extend its shelf life. On the other hand, it is possible that garlic contains a bacteria responsible for botulism. Thus stored in oil (without oxygen), the conditions are optimal for the development of toxins.

 Consumption of a spoiled product can lead to serious food poisoning which manifests itself in symptoms such as dizziness, blurred or double vision, difficulty breathing, swallowing and speaking. The appearance, smell and taste of deteriorated oil will not necessarily change, hence the importance of observing the following guidelines:

  • Always keep garlic stored in oil in the refrigerator;
  • Consume immediately or within a week of homemade garlic oil. Commercial garlic oils should contain preservatives (acids, such as vinegar, or salt): check the product label.
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Other side effects of consuming too much garlic

  • Garlic can affect the taste of breast milk. Breastfeeding women should therefore watch their garlic consumption during this time;
  • Consuming a high and regular amount of garlic could affect blood glucose; people with diabetes should pay special attention to this;
  • Excessive consumption of raw garlic, especially when the stomach is empty, can cause gastrointestinal disorders: ingesting one to two cloves of garlic per day is a safe dose for an adult.

 History and anecdotes

A little history

The term “garlic” comes from the Latin allium. It could be derived from a Greek word meaning “to spring from”, alluding to the very rapid way the bulb divides into several cloves, which seem to literally spring from it. Others think it comes from Celtic all, which means “spicy”.

The center of origin of garlic is said to be a large crescent (the “garlic crescent”) that stretches from the Caspian Sea in the west to the Tian Shan Mountains on the border with China. and Kazakhstan to the east. In this vast region, there are about 150 wild species belonging to the genus Allium. On the other hand, we have not found the wild ancestor of cultivated garlic (Allium sativum).

The oldest writings on its culture date from the Sumerians (2500 BC), but it was consumed long before as a spice or remedy. Known to the Egyptians, Greeks and Romans, it will spread across southern and eastern Europe. It will not know the same glory in the countries of the north and in the British Isles, except sometimes as a medicinal plant in the gardens of the monasteries. 

Transported by the sailors who always keep it to protect themselves from epidemics and the evil eye, it will reach the Dominican Republic with Christopher Columbus and will then be disseminated throughout South America and Central America. However, it was not until the 19th century that it arrived in North America, under the influence of Mexican cuisine, which was very fond of it. It will find fertile ground in California, particularly in the Gilroy Valley, where it will be cultivated on a large scale and where people will not hesitate to grant themselves the status of “international capital of garlic”.

Did you know ? Shakespeare considered that garlic was not made for the nobles and Cervantes recommended not to eat either onion or garlic at the risk that their smell would betray a deplorable peasant origin. “Stinking rose”, “imprint of Satan’s left foot”, the most vehement qualifiers have never failed to describe it.

A little botany 

In Quebec, garlic is sown between September 15 and October 15, and harvested in July of the following year. For flower bed cultivation, the ideal spacing is 12 cm by 20 cm. For row cultivation, the plants should be spaced 15 cm apart, and the rows 20 to 25 cm apart. To ensure that garlic survives the vagaries of winter, it is recommended to cover it with a very thick mulch (dead leaves, straw or old hay). Remove the mulch in April or May to allow the soil to warm up and the plants to loosen, then replace it to prevent the emergence of weeds, against which garlic, with its narrow leaves, is helpless.

To promote bulb growth, the flower stems of stick garlic varieties will be cut no later than when they reach 15 cm (around mid-June in southern Quebec). We can let a few flower stems grow: their deployment is a spectacle in itself and, moreover, we can harvest the bulbils that will form later at its end to use them as seeds or in food. By the way, it is for the hens, who love them (the bulb and bulbils), an almost surefire way to decrease the incidence of infectious diseases in the henhouse, especially salmonellosis.

The harvest is done from mid-July to mid-August depending on the variety and the region, ie when there are five or six green leaves (out of the original ten) on the stem. The whole plant, with its leaves and roots, will be hung in a dry place in the shade for a period of two to four weeks to complete the process of ripening and drying of the bulbs. When harvesting, one must absolutely resist the urge to wash the bulbs, as this may hamper the ripening process. Once the bulbs are completely dry, cut the roots flush and the stems to two or three centimeters. Set aside medium sized pods for seed, making sure they are all very healthy.

Garlic and misconceptions

Some say brushing teeth after eating garlic reduces bad breath, but brushing teeth has no effect on garlic breath, since the characteristic odor comes from gases released in the garlic. mouth when chewing, then in the digestive tract throughout digestion. These gases take at least three hours to be eliminated. The best way to reduce your breath after a meal is to chew on parsley, mint, or coffee beans. Moreover, according to a garlic lover who was definitely not lacking in humor, “a five-cent piece may allow you to take the train, but garlic will guarantee you a seat”.

In the opinion of some good eaters, the only really effective method to avoid annoying those around him with sulphurous breath would be to convince them to eat garlic at the same time as yourself …

Garlic Benefits & Nutritional values
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