Hi there
Just a thought. Most herbal supplements etc need to be taken for for quite some time before the effects will be noticeable. Could be the case with curcumin. My boyfriend John (34 wCF) started it on max dose and turned yellow(!)but is still continuing with a lower dose. He has also just started GSH orally and DHA. In Cf there are so many deficiencies and these things tend to work in concert so I wouldnt give up just yet.
Definetly try GSH - glutathione. The evidence for supplementation is overwhelming and it is a major antioxidant. Most of the damage to CF lungs is caused by oxidation and inflammation so taking lots of antioxidants, in my opinion, is crucial.
By the way check out www.pycnogenol.com. It is the website of pine tree bark - the most potent antioxidant known and the research has been staggering. It helps inflammation and helps the body make better us of Vitamin C - which incidentally the body cant make so is crucial you supplement. John has just started taking it so will report back.
God bless and good luck to you all
Cazze