The medicinal effect of garlic

Gringo has already written an interesting article about it garlic in Thailand, garlic is widely used in Asian dishes. You also see a lot of garlic in shapes and sizes on the market in Thailand. In this article some background on the health-promoting properties of garlic. 

The medicinal use of garlic is timeless. It's not for nothing that garlic is seen as a remedy for aging; Garlic undeniably counteracts cardiovascular disease, improves blood flow to organs and tissues, strengthens the immune system and protects the body against toxic substances. In addition, garlic is an excellent remedy for various infections with viruses, bacteria, fungi and parasites.

Garlic is rich in unique sulfur-containing compounds, the main component of which is alliin (S-allyl-L-cysteine ​​sulfoxide). The (stable) alliin is converted by the enzyme alliinase into allicin (diallyl thiosulfinate) when fresh garlic is chopped or crushed. Allicin, a very unstable substance, is then quickly converted into more than a hundred active metabolites (thiosulfinates). Good garlic preparations mainly contain alliin, which is converted in the intestines and elsewhere in the body into metabolites with a strong medicinal effect (allicine and others).

Garlic affects factors that play a decisive role in the pathogenesis and progression of atherosclerosis. Garlic decreases total and LDL cholesterol and triglyceride levels, increases beneficial HDL cholesterol, decreases fibrinogen levels, decreases arterial blood pressure, increases fibrinolysis, inhibits platelet aggregation and decreases blood viscosity. Allicin and S-allylcysteine ​​protect endothelial cells and LDL-cholesterol against oxidation and inhibit atherosclerosis partly on the basis of antioxidant protection. In addition, garlic directly inhibits the atherosclerotic process by counteracting the proliferation of smooth muscle cells in atherosclerotic plaques and fat accumulation in the vessel wall.

Garlic extract lowers systemic blood pressure in hypertension. Because garlic (in vivo) stimulates the enzyme nitric oxide synthase in the vascular endothelium, the production of the vasodilator nitric oxide (NO) increases. The reduction in blood pressure is also due to hyperpolarization of the smooth muscle cells in the blood vessels and/or inhibition of the opening of calcium channels in the muscle tissue. Inhibition of angiotensin-converting enzyme (ACE), modulation of prostaglandin synthesis or influencing the atherosclerosis process may also play a role.

Garlic extract (including allicin, S-allyl cysteine ​​and diallyl disulfide) has a strong antioxidant effect and provides protection against lipid peroxidation, counteracts the formation of superoxide anion radicals and scavenges free radicals. In addition, intake of garlic leads to an increase in the antioxidant enzymes catalase and glutathione peroxidase in the serum.
Garlic stimulates the activity of macrophages, lymphocytes and natural killer cells. By inhibiting the enzymes lipoxygenase and cyclooxygenase, garlic reduces the uncontrolled formation of pro-inflammatory eicosanoids (prostaglandins, leukotrienes and thromboxanes).

Garlic has very broad antimicrobial activity and is effective against gram-positive and gram-negative bacteria, viruses, parasites and yeasts and fungi including Candida albicans. The toxin production by the micro-organisms present is also counteracted by garlic. One mg of allicin is equivalent in potency to approximately 15 IU of penicillin. Garlic is also effective against intestinal parasites. For example, allicin kills dysenteric amoebae (Entamoeba histolytica) by blocking cysteine ​​proteinases and alcohol dehydrogenases in the amoeba.

Allicin inactivates the enzymes of pathogenic bacteria, viruses and fungi by reacting with the thiol group (SH or sulfhydryl group) of the enzyme. Mammals have much less proteins with SH groups than lower organisms. In the human body, glutathione therefore protects the thiol groups from damage. Micro-organisms that are sensitive to garlic are fortunately unable to develop resistance to garlic due to garlic's profound mechanism of action.
In vitro and in vivo studies have shown that garlic strengthens the immune system, partly due to the antioxidant effect of garlic. Allicin and numerous metabolites including diallyl sulfide (DAS), diallyl disulfide (DADS) and gamma glutamyl methyl selenocysteine ​​(GGMSC) are responsible for this.

Di- and trisulfides and allyl mercaptan from garlic also chelate heavy metals such as mercury, cadmium and lead. Not unimportantly, components in garlic induce phase II detoxification enzymes in the liver and other organs, improving the breakdown and excretion of toxins and protecting the body against highly reactive phase I detoxification metabolites. Garlic protects the liver against toxic substances such as aflatoxin, benzopyrene and acetaminophen. The effect of garlic decreases sharply when fresh garlic is heated.

From folk medicine it is known that garlic supports digestion, counteracts dysbiosis and promotes appetite.

Garlic can lower blood glucose levels. At least that's what animal research shows. Human studies are less clear. Garlic may improve insulin release and slow down insulin inactivation.

Contraindications

Be careful when using allium sativum extract before and after surgery and when taking anticoagulant medications (such as warfarin, indomethacin and aspirin), as garlic slows down blood clotting. Allium sativum extract is contraindicated in case of hypersensitivity to garlic and the use of protease inhibitors against the HIV virus. Garlic can significantly lower the blood level of protease inhibitors.

Side effects

Sometimes the use of Allium sativum extracts (especially in high doses) leads to nausea, dizziness, stomach complaints or irritation of the mucous membranes in the gastrointestinal tract. Reducing the dose usually resolves such complaints. An allergic reaction is possible in principle, but is very rare. Fermented garlic has hardly any side effects.

Interactions

Be careful when using blood glucose lowering medicines (sulfonylureas), because in combination with garlic, the blood glucose level can drop more. In theory, garlic extract can also enhance the effect of statins (cholesterol-lowering medication) and ACE inhibitors (medication against high blood pressure). The use of high doses of Allium sativum extract is not recommended for safety reasons when using the said medication. Finally, it is known that Allium sativum extract potentiates the effect of antibiotics.

Source: Naura foundation