Garlic: Cultivation Challenges and Health Benefit Claims

Garlic, scientifically known as Allium sativum L, is a member of the onion family and thrives best in climates with cool winters. This bulbous plant struggles to grow in hot climates, with the quality of home-grown garlic largely depending on the seed bulb used, soil conditions, and the presence of diseases. Among the various types of garlic, the white-skinned Common garlic is the most familiar, while Elephant garlic (Allium ampeloprasum L) is notable for its very large cloves, albeit with a milder garlic flavor.

Garlic is rich in a variety of phytochemicals, the most notable being allicin. Interestingly, garlic does not naturally contain allicin; it is formed when garlic is cut or crushed. This process breaks down the sulfur-containing amino acid alliin through enzymatic action, resulting in the formation of allicin. Allicin is relatively stable when kept cool but starts to degrade when heated, leading to the formation of diallyl sulfides.

Garlic is lauded for its potential health benefits, particularly for cardiovascular issues. It is said to help lower blood pressure, reduce blood lipid levels, and possess anticoagulant properties. Additionally, garlic is believed to have anticancer properties and the ability to fight hepatic and microbial infections. Some reports also suggest that consuming garlic can reduce the frequency and severity of the common cold. However, many of these claims are not robustly supported by scientific evidence.

Recent reviews of scientific literature conclude that, despite the numerous purported health benefits of garlic and allicin, there is insufficient evidence to support these claims conclusively. No definitive mechanisms of action have been identified that can fully explain the alleged benefits. Current research continues to explore these potential effects, but more rigorous studies are needed to substantiate the health claims associated with garlic consumption.

In summary, while garlic remains a popular ingredient both for its culinary uses and its purported health benefits, it is essential to approach its medicinal claims with cautious optimism. The ongoing scientific inquiry may eventually provide clearer insights into the true extent of garlic's health properties.
Garlic: Cultivation Challenges and Health Benefit Claims

Bioactive compounds of garlic

Garlic (Allium sativum L.) is a common spice with many health benefits, mainly due to its diverse bioactive compounds, such as organic sulfides, saponins, phenolic compounds, and polysaccharides.

Garlic is a seasonal vegetable, which loses its beneficial substances during long-term storage. It has been reported that the bioactive compounds of the green parts of garlic can provide the same health benefits as garlic cloves.

Fresh garlic bulbs contain about 60 % of water, 32 % of carbohydrates and 6,5 % of fiber. Vitamin C is present in the greatest amount (about 31 mg in 100 g of product). Garlic also supplies vitamins from A, B1, B2 and PP group. Among mineral ingredients, potassium is present in the highest concentration, whilst iron, magnesium and phosphorus in a slightly lower concentration.

The main quality feature of garlic products is the distinct flavor of cloves, as the result of complex biochemical reactions. The main responsible compounds for that flavor are sulfur-containing non-volatile amino acids (thiosulfinates), among which alliin or S-allyl-cysteine sulfoxide (ACSO) comprises the most predominant garlic flavor precursors.

Apart from their flavor attributes, these sulfur compounds are also responsible for the renowned medicinal properties of garlic, and additionally may improve the biosynthesis of glutathione, from which important antioxidant functions are known.

In general, organosulfur compounds in raw garlic have higher digestibility than those in cooked garlic. In addition, saponins were found to be more stable in the cooking process.

Other important volatile compounds, with prominent bioactive properties are ajoenes, as also several sulfur-containing compounds, such as allicin, 1,2-vinyldithiin, allixin and S-allyl-cysteine and sulfides, such as diallyl-, methyl allyl-, and dipropyl mono-, di-, tri- and tetra-sulfides.

A pioneer study supports the role of garlic in cancer as diallyl sulfide, diallyl disulfide and garlic extract showed role in reduction of anti-proliferative gene and propose that modulation of apoptosis linked cellular proteins in the in non-small cell lung cancer cells.
Bioactive compounds of garlic

Allicin in garlic

Garlic contains a wide variety of phytochemicals, but most attention has centered on allicin. Allicin is the substance that gives its distinctive aroma and flavor.

Garlic, in fact, does not normally contain allicin. Allicin is a “dormant” compound found in garlic. Allicin is formed when garlic is cut. The sulphur containing amino acid alliin is broken down by enzymes to form allicin. This process produces the familiar aroma associated with garlic.

Allicin is the pungent, hot, stinky stuff that makes garlic special. Allicin is relatively stable if it is kept cool, but starts to degrade when heated. As allicin breaks down, diallyl sulphides are formed.

Allicin has antioxidant properties including the ability to trap the free radicals that cause damage to healthy cells within the body. Allicin also has antiviral activity and has been proven effective against many common viruses, including herpes and influenza.
Allicin in garlic

Health Benefits of Garlic

Thousands of research papers have been published in the United States alone pointing to garlic’s beneficial effect on heart disease, cancer and infectious. It is one of the best examples of an age old medicinal plant that is still one of the most effective herbs for the major diseases of time. Garlic belongs to the lily family and it is a perennial plant that is cultivated worldwide.

*Garlic lowers blood pressure. Study from the University of Alabama at Birmingham suggests that eating garlic, may lead to relaxation of blood vessels, thus lowering high blood pressure.

*Garlic lowers LDL cholesterol. Garlic also can normalize plasma lipid.

*Garlic lowers or helps regulate blood sugar.

*Garlic provides protection from heart disease by preventing clots that can lead to heart attacks and strokes and can reduce high blood pressure significantly.

*Garlic helps prevent cancer, especially of the digestive system, prevents certain tumors from growing larger, and reduces the size of certain tumors. In an exciting study form the Medical University of South Carolina, researchers found that garlic may kill the cells that cause glioblastoma, a fatal brain cancer.

*Garlic helps to remove heavy metals such as lead and mercury from the body.

*Garlic is a potent natural antibiotic. Fresh garlic is effective against bacteria, yeasts, and fungi. It is most effective against fungi and candida.

*Garlic has anti-oxidant properties.

*Garlic is a source of selenium.
Health Benefits of Garlic

Garlic beneficial effects

Used for centuries as a flavoring ingredient in food, garlic is believed to carry many beneficial effects.

Garlic is an excellent source of vitamin B6, vitamin C and manganese. Garlic has anti-inflammatory, anti-bacteria, anti-oxidant and antiviral properties.

Garlic is the richest source of selenium among the edible plants, but because it is eaten in such small quantities, its selenium contribution to the diet is minimal.

Routinely eating garlic has an effect on the lining of the blood vessel walls which causes them to relax; thus helping to reduce the risk of heart attack and stroke.

Garlic glycosides and lower blood pressure and can decrease blood lipids and thus may be good prevention for arteriosclerosis.

According to the Commission E, German’s regulatory agency for herbs, all forms of garlic - including fresh, powdered, oil and aged extract – act similarly in reducing cholesterol synthesis and platelet aggregation and all exhibit anti-bacterial, anti-fungal and anti-viral action in both laboratory and animal studies.

The essential oil of garlic is the sulfur rich allicin or allyl, which is found in the onion family and is the cause of garlic’s pungent odor.

Allicin is only formed when the garlic is crushed. Cooking and heating destroys the necessary enzymes for the formation of allicin.

Garlic is also a good source of nutrients as saponins, polyphenols, selenium, arginine and vitamin C.
Garlic beneficial effects