Curcumin has many anti-inflammatory properties. , ,  Found in the turmeric root, the active ingredient is generally recognized as curcuminoids.
You can ingest curcumin several ways. You can eat the turmeric root. It is delicious in a stir-fry with mixed vegetables, but you can also eat the ground root as a powder. Populations that ingest a lot of turmeric have been associated with decreased risk of development of many chronic medical illnesses.
The second way to ingest curcumin is via a curcumin supplement. These can be capsules of curcumin which come in different sizes. The best formulation is to get one that is at least 90% or greater curcuminoids. Some products are specially formulated to increase the bioavailability of the curcumin, so you get better absorption of the active curcuminoids.
The recommendation is to take at least 500 mg of curcumin (as active curcuminoids) twice a day. A formula that boosts the absorption of curcumin may come in lesser strengths, such as 400 mg curcumin. However, if specially formulated to boost absorption, you actually get more curcumin into your system and the benefit is multiplied. Adding a black pepper extract, piperine or bioperine, may increase the absorption hundreds of times over.
Curcumin absorption systemically is important, but so are the effects of curcumin on the gastrointestinal tract. Curcumin has been shown to have beneficial effects on intestinal flora (microbiota), intestinal permeability (less leaky gut), gut inflammation and oxidative stress. It has been postulated that some of the beneficial effects of curcumin to the body are at least partially due to these gastrointestinal effects. 
Chronic inflammatory diseases such as IBS or Crohn’s disease have been improved with curcumin. These are inflammatory diseases of the GI tract. The decreased inflammation that curcumin provides in inflammatory bowel diseases is most likely at least partly the reason why curcumin is helpful in these conditions.
Decreasing inflammation in the gut may also decrease the “leaky gut” problem that can happen from chronic inflammation of the gut with subsequent “leakage” of this inflammation into the general circulation. This has been associated with many chronic inflammatory conditions in the body such as arthritis and autoimmune diseases.
Curcumin has multiple systemic body effects due to suppress acute and chronic inflammation. It inhibits the formation of many compounds that induce inflammation, including cytokines, IL-1, and TNF-alpha. and others. These work by recruiting other inflammatory cells to migrate to the areas affected. This blocks the inflammatory response; after all, if they are not called to come to the area, they cannot cause the inflammatory reaction to occur in the tissues.
Other inflammatory compounds that curcumin has been shown to inhibit phospholipase, lipoxygenase, cyclooxygenase 2, leukotrienes, thromboxane, prostaglandins, and others. Six human clinical trials have demonstrated anti-inflammatory activity of curcumin.
Curcumin is also an antioxidant, and thus can neutralize free radicals that can cause tissue damage. It has shown to be at least 10 times more active as an antioxidant than vitamin E. Reducing oxidative damage also decreases inflammation.
Curcumin has been shown to have antiviral activity against certain viruses. In addition, it has some effectiveness in vitro against HIV and herpes virus. The combination of all these aspects of curcumin suggests it could have some effectiveness in fighting off COVID-19.
The COVID-19 viral infection does cause inflammation of the tissues. Thus, the powerful anti-inflammatory effects of curcumin may help in decreasing the severity of the disease since the severity is at least partly due to inflammatory reaction that occurs in the lungs in those with the infection. However, no studies have been performed on the Corona virus and using curcumin.
Curcumin has a variety of anti-inflammatory and antioxidant properties that help decrease risk of developing many chronic medical illnesses and may have some effectiveness in decreasing severity of the COVID 19 viral infection.
The above statements regarding the use and effectiveness of curcumin have not been evaluated or approved by the FDA. Curcumin cannot prevent, diagnose, treat, or cure medical problems.
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