Hi 2roses,
we tried both curcumin and quercetin. We noticed positive effects in both cases: improved fat absorbtion and digestion to the level that we needed to lower the CREON dosage. Quercetin was definitively stronger.
We stopped curcumin because our doctor said that it may impact the liver with high dosage.
Quercetin worked better with natural substances like Roibos or red tea and it does not have the side effects of curcumin. Please, consult a doctor to calculate the proper dosage. Quercetin is not toxic but any natural substance with very high dosage may create problems with the kidneys.
Quercetin works better with DDF508. It could be less beneficial with other mutations.
Some scientific references. Some very recent:
Activation of the cystic fibrosis transmembrane conductance regulator by the flavonoid quercetin: potential use as a biomarker of ?F508 cystic fibrosis transmembrane conductance regulator rescue
http://www.ncbi.nlm.nih.gov/pubmed/20042712
Quercetin accumulates in nuclear structures and triggers specific gene expression in epithelial cells.
http://www.ncbi.nlm.nih.gov/pubmed/21782406
Evaluation of the potential in vivo genotoxicity of quercetin.
http://www.ncbi.nlm.nih.gov/pubmed/18556240
A critical review of the data related to the safety of quercetin and lack of evidence of in vivo toxicity, including lack of genotoxic/carcinogenic properties.
http://www.ncbi.nlm.nih.gov/pubmed/17698276
Quercetin: A potential drug to reverse multidrug resistance
http://www.ncbi.nlm.nih.gov/pubmed/20637779
Possible use of quercetin, an antioxidant, for protection of cells suffering from overload of intracellular Ca2+: a model experiment.
http://www.ncbi.nlm.nih.gov/pubmed/18586279
-----------
father of a beautiful CF girl (DDF508) and strong believer in natural remedies for CF