Fermented Foods and COVID | Natural ACE2 inhibitor?

We first reported on potential, natural strategies worth considering at the beginning of the pandemic. As always there are conflicting thoughts...

To date? No magical cures of course, and reasonably we still must wait for an approved vaccine. Recently though in the flood of COVID research, a population study has come out highlighting one natural contender here worthy of repeat mention. 

Population studies can be dicey, and not each without their own unique caveats. Still, this new publication affords a level of added intrigue, even if indeed with a grain of salt.

The contender? Fermented foods!

Fermented Foods, COVID, ACE2?

Maybe most because of the suggested level of safety, and what appears to be a huge (potential) health payoff. In South Korea, kimchi is an example of a commonly enjoyed, traditional fermented food product, and is at least one nation referenced in the new research. [1]

The Montpellier University team elaborated on what they hypothesize as a link between fatality rate and nationally enjoyed fermentations. This recent population study evaluated a correlation between consumption of fermented foods and rates (and severity) of COVID infection. [1]

Fermented Vegetables ACE2 | Probiotics and COVID

They also contrasted potential benefits of fermented vegetables against traditional fermented milk products. South Korea which consumes a lot of fermented veggies has a relatively low fatality rate, as did countries similar, but not in the case of fermented milk products.

While there is no specific causation, it remains that those countries which have higher consumption of fermented veggies are those with lower fatality rates. Coincidence? 

How does it work? Kimchi and ACE2 | Fermented Foods ACE2

The mechanisms are still under discovery, but natural compounds from fermented vegetables here are explained for a possible balancing effect on ACE2, an enzyme found on certain cell types, especially those in the lungs. 

First reported at the pandemic’s onset, ACE2 is important for targeted treatments because it acts as a primary ‘entry point’ for the virus. And importantly, it’s found in increased levels in those with certain pre-existing conditions, including diabetes and high blood pressure. [2]

Oxidative Stress and COVID | Antioxidants and COVID

One reason these conditions cause increased ACE2 levels is in response to the high levels of “angiotensin 2,” a hormone involved in blood pressure. This hormone causes oxidative stress, and is best when not chronically elevated.

So, ACE2 in this sense protects against undue oxidative stress while controlling that hormone, this very cycle is one reason why ACE2 can be a risk factor for COVID. But it’s not the only determinant either...

In fact, oxidative stress in general may be involved in increased ACE2 activity. [2] Here is where lifestyle and diet come in. 

How to lower ACE2

As high levels of ACE2 may be in response to a variety of free radicals, certain choices which might limit oxidative stress (or naturally increase antioxidants) may serve similar benefits against the virus, either directly or indirectly staying ACE2 in a healthier range.

In the case of fermented vegetables, natural probiotic properties affect metabolism in the gut, optimizing key nutrients and co-factors involved in your body’s natural antioxidant defenses. While also imparting their own antioxidants. [1]

The new population study essentially recommends how fermented veggies may activate your body’s preferred antioxidant pathways. [1,3]

And by relying on primary antioxidants, the body doesn’t have to rely on secondary antioxidants (e.g. ACE2 could be considered one).

Fermented veggies, exercise, and matcha green tea are all examples which naturally increase antioxidant levels in the body.

How to Reduce Risk of COVID

Most importantly, these lifestyle strategies keep your health stocked up on the right antioxidants. This way, your body doesn’t have to call in reinforcements, and perhaps, you can leave that viral doorway (ACE2 enzyme) closed – or at least not wide open.

Exercise might be a given, but it’s additional assurance that both fermented veggies and matcha tea impart a probiotic effect in the gut.

The microbiome is a key foundation to our entire physiology. At least for COVID it may be either friend or foe, and fermented veggies and matcha tea may very well be deciding factors. 


-Team Matcha Kari



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[1] Fonseca, S., Rivas, I., Romaguera, D., Quijal, M., Czarlewski, W., Vidal, A., ... & Cunha, L. M. (2020). Association between consumption of fermented vegetables and COVID-19 mortality at a country level in Europe. medRxiv.
[2] Samavati, L., & Uhal, B. D. (2020). ACE2, Much More Than Just a Receptor for SARS-COV-2. Frontiers in Cellular and Infection Microbiology, 10, 317.
[3] Senger, D. R., Li, D., Jaminet, S. C., & Cao, S. (2016). Activation of the Nrf2 cell defense pathway by ancient foods: disease prevention by important molecules and microbes lost from the modern western diet. PloS one, 11(2), e0148042.