What does it look like?
- Curcumin is a yellow powder most often available in capsule form.
- Examples of commercial curcumin in unmodified form are CurcuFresh9 and combined formulation.7
- Commercial products with adjunct ingredients to improve bioavailability include Meriva®, a Phytosome® delivery system8, CurcuWIN®, which contains other antioxidants.17, 19
- Format and Bioavailability
- Unformulated curcumin has poor bioavailability due to poor absorption, rapid metabolism and elimination from the body.20 In humans, when unformulated curcumin was administered, only low levels of curcumin were detected in the serum of one-third of the individuals given very high doses of curcumin (10,000-12,000 mg/day).21
- Nutraceutical companies have trialled formulating curcumin with adjuvants (e.g. piperine, turmeric oil, etc), nanoparticles, liposomes, micelles, nano-curcumin, and phospholipid complexes20, some of which may also be bioactive making a clean inference to the bioaction of curcumin difficult. Processing may also provide curcumin metabolites which have a shorter half-life20, 22. Some authors have used more bioavailable forms.8, 11, 19
- Only two studies have used commercially available supplements7, 9, which potentially require higher doses, but are cheaper for consumers. Currently, there is a lack of clarity on what products are most efficacious and more research and consumer data is required.
- Effective dose of curcuminoids (the bioactive fraction of total curcumin) is probably key to optimal bioactivity i,e. aiming for a total daily dose of at least 200 to 1000 mg per day. There is uncertainty on the safety of curcumin larger than 2g/day and no more than 8 g of total curcumin should be taken per day.23
- Currently, the optimal dose of curcumin for post-exercise recovery is unknown. Previous studies have used 90 to 6000 mg/d doses, with 90 mg the lowest effective dose to show some impact on recovery markers24. Clear benefits to subsequent performance were seen with 500 mg6 or 2.5 g7 of curcumin taken twice daily, for 10 or 5 days respectively.
- Effective dosage for an individual may also be influenced by training volume and intensity, as exercise load affects (generally increases) endogenous antioxidant response. The amount of exogenous antioxidant-rich foods within the normal diet (e.g. fruits and vegetables) can also increase the antioxidant response.