Dr. Theoharides of Tufts University School of Medicine has always been a great source of information on all things immune.
In his latest paper (link in Insta bio), he posits that post-COVID brain fog may involve inflammation via mast cell activation. And one of his all-time favorite phytonutrients for calming mast cell-derived inflammation? LUTEOLIN.
Luteolin is a natural flavonoid plant compound that’s found in good amounts in celery, parsley, broccoli, carrots, peppers, cabbages. However, the super-star luteolin foods are radicchio and Mexican dried oregano (not the regular oregano).
Luteolin is also available as a supplement. I particularly like Neuroprotek by Algonot.