Article Summary
- The low bioavailability of curcumin is caused by its unstable chemical structure, resulting in poor solubility in water, rapid metabolism, and low absorption in the gut, followed by rapid elimination.
- Tetrahydrocurcumin, a primary active metabolite of curcumin, is more stable and more bioavailable than curcumin.
- The bioavailability of curcumin can be further boosted through various formulations and delivery systems.
Curcumin—the yellow pigment found in turmeric—has long been studied to understand its influence on the biological mechanisms associated with several chronic health conditions. Although researchers continue to explore curcumin’s antioxidant properties and its ability to maintain the body’s natural inflammatory responses, its poor bioavailability makes it difficult to know how effective curcumin supplementation really is.
The low bioavailability of curcumin is attributable to its chemical instability, which leads to poor solubility in water, rapid metabolism, low absorption from the gut, and rapid systemic elimination. This results in very low—or even undetectable—concentrations of curcumin in blood and extraintestinal tissues after supplementation.
Several human studies have investigated the poor absorption of curcumin. A dose escalation study was performed on 24 healthy participants to determine the maximum tolerated dose and safety of a single dose of curcumin powder extract. With doses ranging from 0.5 g to 12 g, the study revealed excellent tolerance of curcumin; however, no curcumin was detected in the serum of the subjects given amounts between 0.5g and 8g. Low levels of curcumin were detected in participants administered 10 g or 12 g.
To overcome this problem, various approaches have been undertaken to increase curcumin’s bioavailability. Today, the most promising of these involves turning to tetrahydrocurcmin.
Tetrahydrocurcumin: The Most Bioavailable Form of Curcumin
The bioavailability of a nutritional supplement relies on two key factors: transformation in the gastrointestinal (GI) tract and bioaccessibility. Several human studies have tracked the degradation of orally ingested curcumin in humans.
In the GI tract, curcumin tightly binds to mucus, which delays uptake by epithelial cells and causes oxidative degradation. After it is transported into epithelial cells, curcumin undergoes extensive Phase I and Phase II biotransformation.
Phase I metabolism reduces curcuminoids into dihydrocurcumin, tetrahydrocurcumin, hexahydrocurcumin, and octahydrocurcumin, followed by Phase II conjugation with sulfate, glucuronide, and glutathione.
Curcumin and its metabolites then proceed to the intestinal lumen for elimination where they are further metabolized by the gut microbiome in the colon, leaving little opportunity for reabsorption. The reabsorbed curcumin compounds are again metabolized by hepatocytes in the liver, transforming them into reduced and conjugated forms — the majority of which enter the bile with only minor amounts entering circulation. After entering circulation, curcumin and its metabolites adhere strongly to proteins, particularly albumin.
Tetrahydrocurcumin—one of the primary active metabolites of curcumin, exhibits pharmacological activities similar to those of curcumin, but it is more easily absorbed in the GI tract. An animal study involving the administration of Curcuma-P® for four weeks showed the presence of tetrahydrocurcumin—but not curcumin—inside subcutaneous adipose tissue.
Science nerds will appreciate the magnitude by which tetrahydrocurcumin shows more stability than curcumin, with a degradation half-life of 813 minutes, compared to 186 minutes for curcumin in a cell culture medium. In plasma, the half-lives of curcumin and tetrahydrocurcumin are 111 minutes and 232 minutes, respectively.
Several other studies have shown that tetrahydrocurcumin is more active than curcumin and appears to be a superior antioxidant with enhanced bioavailability.
Enhancing the Bioavailability of Curcumin
There are several nutritional supplement formulations designed to enhance curcumin’s bioavailability. A combination of curcumin and piperine—the natural alkaloid of black pepper, for example, produces significantly higher serum concentrations of curcumin than with curcumin alone. Similarly, a curcuminoid mixture with lecithin has better bioavailability than a non-lecithin curcuminoid mixture.
Curcumin in hydrophilic nanoparticles shows enhanced gastrointestinal absorption. A study on comparative absorption of curcumin formulations revealed a 46-fold increase in oral absorption of a water-soluble curcumin formulation compared to unformulated curcumin.
Healthcare professionals may be encouraged to learn that delivery systems like liposomes, micelles, microemulsions, nano-emulsions, phospholipid complexes, nanostructured lipid carriers, solid lipid nanoparticles, and microgels, all hold great potential in enhancing the bioavailability of curcumin.
Advanced tetrahydrocurcumin formulations, such as TetraCumin®, enhance the bioavailability of curcumin even further with a revolutionary delivery technology designed to ensure maximum absorption. The enhanced curcumin absorption, in turn, unlocks the immense therapeutic potential of curcumin for supporting musculoskeletal health and immune function in the body.
The power of Tesseract supplements lies in enhancing palatability, maximizing bioavailability and absorption, and micro-dosing of multiple nutrients in a single, highly effective capsule. Visit our website for more information about how Tesseract’s products can help support your musculoskeletal health.*
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