Garlic

Origin and history

The well-known garlic ( Allium sativum ) belongs to the allium family. The edible tuber has been used in all cuisines around the world for thousands of years, but originally comes from South and Central Asia and Iran. It is an excellent source of sulfur-containing compounds such as alliin, which our body urgently needs for building proteins, for example. Some compounds are only formed when the garlic is cut or heated. These compounds are also the main reason for garlic's pungent smell and taste.  

In addition to its use in cooking, garlic has traditionally been used for health purposes by people in many parts of the world, including the Egyptians, Greeks, Romans, Chinese and Japanese, dubbed the “all-rounder”. This reputation stems from its numerous medicinal uses throughout history. This is where all the superstitions surrounding garlic developed, which say that it can protect against evil such as demons and vampires.  

Garlic is a source of important vitamins such as vitamins C and B6 and contains minerals such as selenium and manganese. Garlic also provides fiber, which is important for healthy digestion  

As it lives up to its name as an all-rounder, garlic is said to have many health-promoting properties in traditional medicine. These include anticarcinogenic, antioxidant, antidiabetic, renal protective, antiatherosclerotic, antibacterial, antifungal, antiparasitic and antihypertensive properties. Garlic is also known for its immunomodulatory and anti-inflammatory effects. In many cultures it is therefore very popular for colds.  

The antioxidant and anti-inflammatory properties were examined in a study where different levels were observed in cyclists after a 40 km ride. It was found that additional garlic intake did not improve performance, but it reduced training-induced inflammatory levels and weakened muscle damage after training.  

However, what is more evident from studies is that garlic may have many heart-protecting and anti-atherosclerotic (which counteracts narrowing of the arteries) properties. For example, through the observed reduction in the total concentration of blood fat, inhibition of platelet aggregation and lowering of blood pressure. These together could reduce the risk of heart disease. However, more detailed research is still needed and benefits for the cardiovascular system are currently the main focus of research regarding garlic supplementation. Benefits are also suspected for diseases such as diabetes, as it has been observed that ingredients in garlic increased the sensitivity of the cells to insulin and triggered a higher insulin release, which leads to an overall reduction in blood sugar.  

Possible side effects  

Garlic is safe for people without an intolerance. In the case of intolerances such as large quantities on an empty stomach, flatulence and gastrointestinal problems can occur. Burns may occur if used on the skin. At higher concentrations, more severe symptoms may occur. Therefore, for older people, the recommended amount of raw garlic is 4g per day.  

Interactions  

Garlic is safe for people without an intolerance. However, it is suspected that garlic ingredients may interact with some medications. Therefore, those affected are advised not to consume garlic in dietary supplements. The risk of bleeding may be increased if taken, so caution should be taken when taking blood thinners such as warfarin/Coumadin at the same time or before surgery. Garlic may also reduce the effectiveness of some HIV medication, saquinavir.  

Literature:  

1. "Garlic”. National Center for Complementary and Integrative Health, US National Institutes of Health. December 2020. https://www.nccih.nih.gov/health/garlic (Accessed on January 22, 2024)  
2. El-Saber Batiha G, Magdy Beshbishy A, G Wasef L, Elewa YHA, A Al-Sagan A, Abd El-Hack ME, Taha AE, M Abd-Elhakim Y, Prasad Devkota H. Chemical Constituents and Pharmacological Activities of Garlic ( Allium sativum L.): A Review. Nutrients. 2020 Mar 24;12(3):872.  
3. Sobenin IA, Myasoedova VA, Iltchuk MI, Zhang DW, Orekhov AN. Therapeutic effects of garlic in cardiovascular atherosclerotic disease. Chin J Nat Med. 2019 Oct;17(10):721-728.  
4. Shang A, Cao SY, Xu XY, Gan RY, Tang GY, Corke H, Mavumengwana V, Li HB. Bioactive Compounds and Biological Functions of Garlic (Allium sativum L.). Foods. 2019 Jul 5;8(7):246.  
5. Valls RM, Companys J, Calderón-Pérez L, Salamanca P, Pla-Pagà L, Sandoval-Ramírez BA, Bueno A, Puzo J, Crescenti A, Bas JMD, Caimari A, Salamanca A, Espinel AE, Pedret A, Arola L , Solà R. Effects of an Optimized Aged Garlic Extract on Cardiovascular Disease Risk Factors in Moderate Hypercholesterolemic Subjects: A Randomized, Crossover, Double-Blind, Sustained and Controlled Study. Nutrients. 2022 Jan 18;14(3):405.  
6. Varade S, Nadella M, Hirake A, Mungase SB, Ali A, Adela R. Effect of garlic on the components of metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials. J Ethnopharmacol. 2024 Jan 10;318(Pt B):116960.  
7. Tsao JP, Bernard JR, Tu TH, Hsu HC, Chang CC, Liao SF, Cheng IS. Garlic supplementation attenuates cycling exercise-induced oxidative inflammation but fails to improve time trial performance in healthy adults. J Int Soc Sports Nutr. 2023 Dec;20(1):2206809.