Absorption of turmeric
Fresh turmeric (Curcuma longa L.) has been used in India for cooking and in traditional medicine for centuries.
There is clear evidence for the effectiveness of curcumin (the active ingredient naturally present in turmeric) in a wide range of clinical applications. However, curcuminoids are not easily absorbed by the body in their raw state – they are not ‘bioavailable’.
The primary reason curcuminoids are poorly absorbed is because they are not soluble in water. They are also poorly soluble in lipophilic – fatty – solvents. The poor absorbability has not been addressed by many supplements on the market, so there is a huge difference between how effective different supplements are.
How to improve turmeric absorption
In Indian food, turmeric is cooked with animal or plant fats such as butter or coconut oil. In traditional Indian medical use, turmeric is often diluted in warm milk. Putting turmeric into a lipolytic – or fatty – matrix like this provides the means for curcumin to be absorbed by the body.
Curcuminoids can be mixed with lecithin (a type of fat) to form a stable emulsion called phytosome. This patented formulation combines the active ingredient (in this case, curcumin) with a fat molecule (the lecithin) to improve absorption3, mimicking the natural way curcumin has traditionally been consumed in Indian medicine.
Numerous studies conducted in healthy volunteers and patients have validated the effectiveness of the curcuminoid mixture present in supplements. It has been scientifically validated and proven effective in more than 30 human trials, involving 2,000 subjects. The trials have covered 10 different areas including eye health4, 5 joint health6, 8 and supportive care.9, 10
Black pepper
Black pepper is used in many turmeric supplements to increase the absorption of curcumin. Exactly how this happens is not yet clear though. It is thought that black pepper can improve absorption by affecting a variety of cellular and tissue processes11, 12. Black pepper can:
- Increase blood flow around the gut, which can potentially increase absorption of substances in the intestine.
- Inhibit cellular efflux mechanisms, which are used by the cells to secrete compounds such as chemotherapeutic agents and other drugs. In this case, it can decrease the secretion of the curcumin absorbed by the intestine.
- Inhibit glucuronidation, a process that makes substances/drugs more water soluble so they can be easily eliminated from the body.
Although there is some data supporting the effect of black pepper on improving curcumin bioavailability, it is not consistent. How much curcumin will be absorbed will depend on the initial input. In the initial study which is generally quoted regarding the effect of piperine in curcumin bioavailability13, researchers used 2g of curcumin to see an effect on bioavailability, which is much more than what you will find in most supplements.
Liposomal formulation
A popular health supplement brand claims this formulation is over 100x more bioavailable than standard curcumin14. This formulation used curcumin in a liposomal form.
A liposome (also known as micelle) is a lipid solution that encases the active ingredient. Contrary to a phytosome, where the active ingredient is combined with all the lipid molecules, the active ingredient is only found inside the lipid cavity. This means that it is only present on the inside, whereas it will be present all on the surface of a phytosome.
This formulation has only been used in two human studies (one in healthy volunteers and one in people with slightly elevated cholesterol levels)14, 15. These studies focused on the examination of concentration of curcuminoids in serum but not any therapeutic effects. In fact, the study on hyperlipidermic patients didn't show any effect at all, whereas other curcumin formulations have shown some therapeutic effect.
What does this mean?
The effectiveness of a curcumin supplement depends on more than just bioavailability, or its ability to be absorbed. Finding a ‘natural’ way to improve bioavailability is important. It is less likely to cause tolerability issues or unknown side effects with long-term use.
Too much curcumin in the body is not good either, as it can cause tolerability issues over time. Ideally, you only want to absorb enough curcumin to have the beneficial effect you are expecting, and no more.
Therapeutic data on human studies is also very important. It’s all very well to show that more curcumin is absorbed, but if the formulation has no beneficial effect this extra absorption is useless.
Read our definitive guide to turmeric
References
1. Hewlings SJ, Kalman DS. Curcumin A review of its effects on human health food. 2017; 6(10):92.
2. Anand P, Kunnumakkara AB, Newman RA, Aggarwal BB. Bioavailability of curcumin: problems and promises. Mol Pharm. 2007; 4(6):807-818. https://pubmed.ncbi.nlm.nih.gov/17999464/
3. Cuomo J, Appendino G, Dern AS, Schneider E, McKinnon TP, Brown MJ, Togni S, Dixon BM. Comparative absorption of a standardized curcuminoid mixture and its lecithin formulation. J Nat Prod. 2011; 74(4):664-669
4. Miserocchi E, Giuffrè, Cicinelli MV, Marchese A, Gattinara M, Modorati G, Bandello F. Phospholipidic curcumin in juvenile idiopathic arthritis-associated uveitis. Eur J Ophthalmol. 2019;1120672119892804
5. Allegri P, Mastromarino A, Neri P. Management of chronic anterior uveitis relapses: efficacy of oral phospholipidic curcumin treatment. Long-term follow-up. Clin Ophthalmol. 2010;4:1201-1206.
6. Belcaro G, Cesarone MR, Dugall M, Pellegrini L, Ledda A, Grossi MG, Togni S, Appendino G. Efficacy and safety of Meriva®, a curcumin-phosphatidylcholine complex, during extended administration in osteoarthritis patients. Altern Med Rev. 2010;15(4):337-344.
7. Drobnic F, Riera J, Appendino G, Togni S, Franceschi F, Valle X, Pons A, Tur J. Reduction of delayed onset muscle soreness by a novel curcumin delivery system (Meriva®): a randomised, placebo-controlled trial.J Int Soc Sports Nutr. 2014; 11:31.
8. Szymanski MC, Gillum TL, Gould LM, Morin DS, Kuennen MR. Short-term dietary curcumin supplementation reduces gastrointestinal barrier damage and physiological strain responses during exertional heat stress. J Appl Physiol (1985). 2018;124(2):330-340.
9. Tuyaerts S, Rombauts K, Everaert T, Van Nuffel AMT, Amant F. A Phase 2 Study to Assess the Immunomodulatory Capacity of a Lecithin-based Delivery System of Curcumin in Endometrial Cancer. Front Nutr. 2019; 5:138.
10. Panahi Y, Saadat A, Beiraghdar F, Sahebkar A.Adjuvant therapy with bioavailability-boosted curcuminoids suppresses systemic inflammation and improves quality of life in patients with solid tumors: a randomized double-blind placebo-controlled trial. Phytother Res. 2014; 28(10):1461-1467.
11. Smilkov K, Ackova DG, Cvetkovski A, Ruskovska T, Vidovic B, Atalay M. Piperine:Old Spice and New Nutraceutical? Curr Pharm Des. 2019; 25(15):1729-1739.
12. Lee SH, Kim HY, Back SY, Han HK. Piperine-mediated drug interactions and formulation strategy for piperine: recent advances and future perspectives. Expert Opin Drug Metab Toxicol. 2018;14(1):43-57
13. Shoba G, Joy D, Joseph T, Majeed M, Rajendran R, Srinivas PS. Influence of piperine on the pharmacokinetics of curcumin in animals and human volunteers. Planta Med.1998; 64(4):353-356.
14. Schiborr C, Kocher A, Behnam D, Jandasek J, Toelstede S, Frank J. The oral bioavailability of curcumin from micronized powder and liquid micelles is significantly increased in healthy humans and differs between sexes. Mol Nutr Food Res. 2014; 58(3):516-527.
15. Kocher A, Bohnert L, Schiborr C, Frank J. Highly bioavailable micellar curcuminoids accumulate in blood, are safe and do not reduce blood lipids and inflammation markers in moderately hyperlipidemic individuals. Mol Nutr Food Res. 2016; 60(7):1555-1563.