Can Curcumin (or Turmeric) boost the immune system and fight respiratory infection?
There is widespread public interest in using oral Turmeric for various respiratory tract infections, including bronchitis and the common cold. Curcumin is thought to be the active ingredient in Turmeric, however, its effectiveness has not yet been evaluated in clinical trials. While curcumin has been found to exhibit antiviral and immunostimulatory effects in lab-based (in-vitro) and animal studies, there is not yet any convincing evidence of this effect in human clinical trials, meaning that there is currently no real evidence that it can prevent or ameliorate symptoms of the common cold or influenza.
Most products that contain these ingredients make claims of effectiveness on the basis of traditional use of these products in Ayurveda and Traditional Chinese and Indian Medicine. Mind you, it is important to note that absence of evidence from clinical trials does not necessarily mean Curcumin is ineffective, and it may simply mean it has not yet been proven in humans. Many people still advocate for its use on the basis of anecdotal evidence (i.e. reports of effectiveness based on individual testimony).