A great reason to consume quercetin? It blocks the flu virus from entering cells

01/16/2019 / By Ellaine Castillo

Winter is fast approaching, and it’s not just the cold that you have to worry about, but the flu as well. This disease, which is caused by the influenza virus, is very hard to avoid since it is easily be passed on from person to person. Health authorities encourage people to receive their annual flu vaccines to avoid getting infected, but this is not an effective solution to the problem. Moreover, they contain large amounts of neurotoxins that can make your health even worse.

There are different ways through which you can naturally avoid the flu. These include changing unhealthy lifestyle habits that interfere with your immune functions or taking natural immune-boosters. Recently, researchers also found a powerful new ally in flu prevention in quercetin.

In a Chinese study, which was published in the journal Viruses, the researchers treated cells with quercetin either during or after trying to infect them with influenza. They did this experiment to determine if the flavonoid is effective against the flu. The results showed that quercetin was more effective when it was added during infection than after, meaning it works as a preventive measure and not as a therapeutic agent.

Quercetin prevents infection from happening by blocking the entry of the flu virus into the cells. Cell invasion is a crucial part of viral infections since there are certain components inside the host cell that viruses need to live and replicate. To enter the cells, they utilize two proteins called H and N, which vary between viral strains. Treatment with quercetin worked since it was able to block the H protein. The results even showed that the flavonoid was effective against different subtypes of influenza A virus, including H1N1, H3N1, and H5N1. The last variant is especially dangerous since it causes bird flu, which has a 60 percent mortality rate.

When continuously exposed to certain treatments, viruses and even bacteria might start having mutations that make them difficult to kill with existing drugs. Fortunately, viruses did not seem to develop resistance against quercetin. Moreover, using it alongside other antiviral drugs was shown to prevent the development of resistance even when it normally would.

Overall, this study showed that quercetin is effective in preventing the flu since it blocks viral entry into the cell. The discovery of this natural remedy can sway people away from vaccines that have adverse side effects. (Related: New research: flavonoid quercetin fights viral infections, protects against chronic lung diseases.)

Other health benefits of quercetin

Quercetin was already famous even before its antiviral properties were observed. This is because of its potent antioxidant properties and many other health benefits, which include the following:

Protecting the brain — Quercetin protects brain cells against harmful free radicals through its inherent antioxidant properties and its ability to stimulate the production of antioxidant enzymes like superoxide dismutase. Moreover, it can prevent excessive inflammation of the brain, which has been associated with Alzheimer’s, dementia, and meningitis.
Preventing cancer — People who frequently eat quercetin-rich foods can reduce their risk of getting lung cancer, especially if they are under 50 years old. It works by reducing the concentration of tumor necrosis factor alpha, which triggers tumor cell growth and metastasis.
Alleviates allergy — During an allergic reaction, there is an excessive release of histamine and other inflammatory substances. By taking histamine, you don’t just reduce the concentration of these substances, you also reduce your body’s sensitivity to histamine by inhibiting one of its receptors.

Sources of quercetin

Quercetin supplements are widely available on the market, but if you prefer to get it from its natural source, you can choose to eat any of the following foods: