Does garlic help prevent coronavirus infection?

As COVID-19 pandemic spread all over the globe, there has been a rise in the consumption of multivitamins and multimineral tablets. There is speculation of the protective effects of different spices against COVID-19. Along with turmeric, garlic is being popularized as an anti-infective agent against COVID-19. In this article, we review all the existing evidence and conclude if garlic has any protective effect against COVID-19.

Garlic is known to have medicinal effects and it has been part of ayurvedic medicine for centuries. Garlic is proven to have anticancer properties and anti-diabetic effects. It is also proven to lower blood pressure in people with hypertension, regulate cholesterol levels and also stimulate immunity.

There is no research studying anti-COVID-19 properties of garlic. However, there are published articles that looked at anti-viral properties of garlic against respiratory viruses like avian influenza and infectious bronchitis virus. Infectious bronchitis virus is a type of coronavirus. We may have to take these studies as a surrogate to conclude if garlic may have any preventive measures against COVID-19.

A study published in Avicenna Journal of Phytomedicine, looked at the effects of garlic on infectious bronchitis virus, a type of coronavirus, in chicken eggs. Chicken eggs were treated with the infectious bronchitis virus, followed by garlic extract. The study concluded that garlic has inhibitory effects on both the strains of the virus but more effect was found on the vaccine strain than the acute strain.

In another study published in Pakistan Journal of Pharmaceutical Sciences, ginger and garlic extracts were used to study their effects on avian influenza virus (bird flu). Chicken eggs were first infected with the virus and garlic and ginger extracts were used to treat the eggs. The study concluded that both garlic and ginger have anti-viral properties but ginger had more anti-viral activity against avian influenza virus.

There are similar studies on anti-bacterial properties of garlic. In one study published in Asian Pacific Journal of Tropical Biomedicine, ginger and garlic were proven to have significant antimicrobial effects. Garlic was shown to have inhibitory activity against deadly bacteria like Pseudomonas, E. Coli, Proteus, Bacillus Sp and Staph Aureus. Antimicrobial effects on Klebsiella and Enterobacter were not significant enough. Similar inhibitory effects were also found against drug-sensitive and drug-resistant tuberculosis.

Based on the above studies, it is apparent that garlic has anti-viral and anti-bacterial properties. Specifically, garlic has an inhibitory effect on infectious bronchitis virus, a type of coronavirus. It should be noted that none of these studies were conducted in human beings. Nonetheless, they shed light on antimicrobial properties of garlic and the importance of including garlic in our diet.

In conclusion, there is no strong evidence to prove garlic can prevent Novel Coronavirus in human beings. However, it may have some anti-coronavirus properties and it may be included in the diet or taken as a supplement to boost immunity against COVID-19.

References:

1. Shojai T et al. The effect of Allium sativum (Garlic) extract on infectious bronchitis virus in specific pathogen free embryonic egg. Avicenna J Phytomed. 2016 Jul-Aug;6(4):458-267.
2. Ried K et al. Garlic Lowers Blood Pressure in Hypertensive Individuals, Regulates Serum Cholesterol, and Stimulates Immunity: An Updated Meta-analysis and Review. J Nutr. 2016 Feb;146(2):389S-396S. doi: 10.3945/jn.114.202192. Epub 2016 Jan 13.
3. Rasool A. Anti-avian influenza virus H9N2 activity of aqueous extracts of Zingiber officinalis (Ginger) and Allium sativum (Garlic) in chick embryos. Pak J Pharm Sci. 2017 Jul;30(4):1341-1344.
4. Karuppiah et al. Antibacterial effect of Allium sativum cloves and Zingiber officinale rhizomes against multiple-drug resistant clinical pathogens. Asian Pac J Trop Biomed. 2012 Aug;2(8):597-601. doi: 10.1016/S2221-1691(12)60104-X.
5. Dwivedi VP et al. Allicin enhances antimicrobial activity of macrophages during Mycobacterium tuberculosis infection. J Ethnopharmacol. 2019 Oct 28;243:111634. doi: 10.1016/j.jep.2018.12.008. Epub 2018 Dec 8.