Garlic (Allium sativum) Health Benefits

Garlic (Allium sativum L.) has acquired a reputation in different traditions as a prophylactic as well as a therapeutic medicinal plant. Garlic has played important dietary and medicinal roles throughout the history. Some of the earliest references to this medicinal plant were found in Avesta, a collection of Zoroastrian holy writings that was probably compiled during the sixth century BC (2)

Active constituents

Allium sativum contains many chemical ingredients, including 17 amino acids, more than 33 OSCs, 8 minerals (calcium, potassium, magnesium, germanium, selenium, copper, zinc, and iron), vitamins (A, B1, B2, B3 B6, B12, C, D, E), and some enzymes (allinase). (6)

Approximately 100 organosulfur compounds have been identified in garlic EO from Allium sativum, with diallyl sulfide, diallyl disulfide, allyl methyl sulfide, and diallyl trisulfide as the principal compounds. Novel sulfides called garlicnins have also been isolated from Allium sativum L. and were shown to modulate macrophage activity. (8)

Cholesterol and Cardiovascular Health

Garlic and its preparations have been widely recognized as agents for prevention and treatment of cardiovascular diseases. The wealth of scientific literature supports the proposal that Garlic consumption has significant effects on lowering blood pressure, prevention of atherosclerosis, reduction of serum cholesterol and triglyceride, inhibition of platelet aggregation, and increasing fibrinolytic activity. Both experimental and clinical studies on different Garlic preparations demonstrate these favorable cardiovascular effects. (2)

Long-term application of Garlic and its preparations on experimental atherosclerosis induced by a high cholesterol diet, showed 50% reduction in atheromatous lesions, particularly in the aorta. Most of the human studies on lipid-lowering effects of Garlic and Garlic preparations described a significant decrease in serum cholesterol and triglyceride. (2)

Improved immune function

The medicinal effects of garlic have been well documented, and natural garlic products have been shown to have antimycobacterial activity which is effective against tuberculosis. (5).

Experimental results indicate that Garlic appears to enhance the functioning of the immune system by stimulating certain cell types, such as macrophages, lymphocytes, natural killer cells, dendritic cells, and eosinophils by mechanisms including modulation of cytokine secretion, immunoglobulin production, phagocytosis, and macrophage activation. Garlic has also been shown to modulate/regulate immune activity (1)

Data from one study where participants were taking only 5g of raw crushed garlic daily indicated that the bioactivity of garlic is multifaceted and includes activation of 7 genes related to immunity and metabolism in humans. (7)

Immune system cells called Neutrophils are a type of phagocyte and are normally found in the bloodstream. During the beginning (acute) phase of inflammation, particularly as a result of bacterial infection, environmental exposure, and some cancers, neutrophils are one of the first-responders of inflammatory cells to migrate towards the site of inflammation. Results of one study demonstrate that certain organosulfur compounds can activate neutrophil functional activity and may serve as biological response modifiers by augmenting phagocyte functions. (8)

Anti-fungal

Garlic has been studied for its potential antifungal properties, particularly against Candida albicans, a common cause of yeast infections.

Garlic contains allicin, a compound with notable antifungal activity, which can inhibit the growth and viability of Candida yeast cells.

These effects are due to allicin’s ability to interfere with the lipid layer on the yeast cell walls, leading to cell damage and disruption of the yeast’s metabolic functions. (9)

A vaginal cream containing garlic and thyme was tested and was as effective as much as Clotrimazole vaginal cream (Canesten) for the treatment of candida vaginitis. (3)

Anti-Bacterial

Numerous publications have introduced allicin as an effective molecule against infectious agents and this fact has been repeatedly confirmed. Based on reports, bactericidal activity of allicin has been verified against important pathogens, including Enterococcus spp, Bacillus spp, Helicobacter pylori, Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, and Vibrio cholera, as well as methicillin-resistant Staphylococcus aureus strains. (6)

Anti-parasitic

Findings demonstrate the effect of allicin (from Garlic) on adult helminth worms and indicate that most of the changes occur at high concentrations. (4)

Several studies suggest that garlic because of containing the sulfur compounds like allicin can delay and prevent the growth of parasites such as Leishmania major, Crithidia fasciculata, Leptomonas colosoma, Giardia lamblia, Tetratrichomonas gallinarum, Cryptosporidium baileyi, Plasmodium berghei, Histomonas meleagridis, and Trypanosoma spp (6)
I recommend swallowing up to six whole cloves daily for 14 days.

Anti-Cancer

Several studies have been conducted to determine the chemopreventive and anticarcinogenic role of garlic’s main component since the in vitro and in vivo studies of Weisberger and Pensky, which showed garlic thiosulfinate inhibit the tumor cell growth. (6)

Garlic components have been found to block covalent binding of carcinogens to DNA, enhance degradation of carcinogens, have anti-oxidative and free radical scavenging properties, and regulate cell proliferation, apoptosis, and immune responses. Ajoene, a garlic stable oil soluble sulfur-rich compound and garlic-derived natural compound, have been shown to induce apoptosis in leukemic cells. (2)