Increasing Post-Digestive Solubility of Curcumin Is the Most Successful Strategy to Improve its Oral Bioavailability: A Randomized Cross-Over Trial in Healthy Adults and In Vitro Bioaccessibility Experiments

Flory S, Sus N, Haas K, Jehle S, Kienhöfer E, Waehler R, Adler G, Venturelli S, Frank J · Molecular Nutrition & Food Research

The only head-to-head of the major formulation strategies in humans. Micelles (57-fold) and the gamma-cyclodextrin complex (30-fold) were the only formulations to raise AUC0-24h significantly. Phytosomes and submicron particles rose 7.5-fold and 6.5-fold non-significantly. The piperine-containing adjuvant arm reached a mean AUC0-24h of 18.65 nM·h against 19.06 nM·h for native curcumin — no increase at all — and liposomes and turmeric oils likewise did nothing. No free curcumin was detectable in any subject on any formulation.

Population

Healthy adults, randomized double-blind crossover, Germany

Intervention

A single 207 mg curcumin dose from eight formulations: native extract, liposomes, turmeric oils, adjuvants including piperine, submicron particles, phytosomes, gamma-cyclodextrin complex and micelles

Comparator

Native curcuma extract

Limitations

n=12, single dose, healthy adults, and a single commercial product represents each strategy — the adjuvant product combined piperine with other adjuvants rather than testing piperine in isolation. University-funded (Hohenheim), independent of the products tested.