NEWSLETTER NOVEMBER 2020
Resveratrol: natural regulator - the role of resveratrol in COVID
Dietary factors including resveratrol can modulate the immune system in a variety of ways. Resveratrol is a polyphenol with antioxidant, anti-inflammatory, antiviral, and neuroprotective properties. Resveratrol occurs in various plant species, but especially in the skins of blue grapes, berries and plums. Lin et al. Showed in 2017 that resveratrol significantly inhibits viral replication of the directly Corona-related virus MERS-COVID in the cells.  This resulted in less severe respiratory symptoms in the group that received resveratrol compared to the untreated control group. COVID-19 activates the so-called NLRP-3 inflammasome, which leads to a cytokine storm and a lot of tissue damage. In a 2016 review entitled 'Natural sub-stances as regulators of NLRP-3 inflammasome-mediated IL-1 beta production' resveratrol, curcumin, EGCG, and quercetin are mentioned as potent inhibitors of NLRP-3 inflammasome-mediated IL-1 beta production. 
- Resveratrol is found in, among other things, blue grapes, blueberries, and pistachios.
- In addition to modulating NLRP3, curcumin in turmeric may also have a COVID Main protease-inhibiting effect, slowing down the multiplication of the virus.
- ECGC in green tea modulates and the NLRP3 inflammasome possibly inhibits the COVID-19 Main protease.
- Quercetin is found in, for example, onions, red apples, and citrus fruit. It has antiviral effects against RNA and DNA viruses, including influenza, the coronavirus, and herpes virus. It has anti-inflammatory effects and modulates several biochemical pathways associated with post-transcriptional modulators involved in the healing of the body after viral infection.
Quercetin promotes inactivation and elimination of viruses and inhibits viral replication and NLRP-3 inflammasome. More research is needed into the effectiveness of quercetin in the COVID-19 virus specifically.
Modulating action of nutrients
Various substances naturally occurring in food and herbs may have a modulating effect on the attachment, cell penetration, and multiplication of the COVID-19 virus and inflammatory (cytokine) storms caused by the virus. This is due to their influence on the ACE-2 receptors, furin and COVID Main proteases, and inflammasomes NLRP3.
Examples include luteolin, quercitin, curcumin, resveratrol, ECGC, glycyrrhizin, Andrographis paniculata, and baicalin. Baicalin is also a polyphenol of the flavonoids group. More research is needed into the effectiveness and correct dosage of these substances to arrive at a natural, effective approach to the prevention and treatment of the COVID-19 virus.
 Lin SC, Ho CT, Chuo WH, et al. Effective inhibition of MERS-CoV infection by resveratrol. BMC Infect Dis 2017;17:144-54.
 Tyzsér J. and Benky S., Natural Compounds as Regulators of NLRP3 Inflammasome-Mediated IL-1 Production, Mediators of Inflammation, Volume 2016, Article ID 5460302, http://dx.doi.org/10.1155/2016/5460302
Immune-boosting role of vitamins D, C, E, zinc, selenium and omega-3 fatty acids: promising protectors against covid-19
A number of nutrients such as vitamins A, C, D and E, the minerals zinc, selenium, magnesium and omega-3 fatty acids have been associated with improved out-comes to the defense against Covid-19:
1. Vitamin D
Vitamin D appears to be a promising protector against covid-19.
Since anthocyanins can be found in almost all plant families, they are also found in many edible plants. The main sources of anthocyanins in our food are berries, such as blackcurrants, redcurrants, blackberries, blue grapes, blueberries, aronia berries, cranberries, elderberries, raspberries, as well as some vegetables, such as eggplant and avocado. Other important sources are oranges, elderberries, olives, red onions, figs, sweet potatoes, mangoes, and red cabbage.
Polyphenols are generally divided into lignans, coumarins, stilbenes, flavonoids, neoflavonoids, isoflavonoids, quinones, hydrolyzable and condensed tannins. These substances can disrupt the function of viruses. For example, the procyanidins in bilberry (vaccinium myrtillus) and cranberry (cranberry) inhibit the action of bacteria that cause infections. Various flavanols from green tea have also been shown to have an effect against viruses so that drinking a large pot of high-quality green tea can have a resistance-increasing effect.
Due to the lack of zinc reserves, too low a zinc intake with the diet can lead to
(reversible) health problems such as fatigue and an increased (virus) infection sensitivity within a few weeks. A zinc deficiency also results in a reduced sense of taste and smell, which is often seen in COVID patients.
Selenium is also a mineral essential for immunity. A group of researchers led by Margeret Rayman (University of Surrey, UK) has found a link between selenium status and COVID-19 in China. In selenium-poor areas, COVID-19 patients are less likely to recover than patients living in selenium-rich areas of China. Selenium sources are; meat, fish, eggs, Brazil nuts, broccoli, cabbage, garlic, mushrooms.