Which Curcumin preparation should I use? Much of the information below is derived from a talk given by Samuel Peters entitled ‘The Curcumin Conundrum: Balancing Bioavailability with Clinical Efficacy’.
I often get asked which is the best curcumin formulation to use. There are approximately twenty commercially available preparations of curcumin available out there – in multiple delivery systems. These delivery systems have been developed to enhance the stability and bioavailability of curcumin. The major obstacle for the clinical application of curcumin is poor bioavailability which is evidenced in clinical trials showing negligible or undetectable serum plasma curcumin levels after oral consumption. Low aqueous solubility, poor absorption, and rapid metabolism and elimination are the three primary causes.
The term ‘curcumin’ is often used to refer to the total curcuminoids - curcumin is the primary curcuminoid found in the turmeric root, the others are demethoxycurcumin and bisdemethoxycurcumin. Most currently available preparations contain all three curcuminoids in varying ratios.
The delivery systems include the use of adjuvants such as piperine, liposomal curcumin, curcumin nanoparticles, curcumin phospholipid complexes, and the use of structural analogs of curcumin such as turmeric oil. Some of the names of these formulations are BCM-95, Novasol, Curcuwin, CurQfen, Biocurc, Theracurmin, Meriva, Longvida, Cureit, and Curcumin C3 complex plus bioperine.
There are many claims that an increase in plasma curcuminoid concentrations indicates superior efficacy, and numerous technologies have been employed to bypass gastrointestinal metabolism and increase delivery of curcumin to the tissues. Despite this focus, numerous studies utilising concentrated curcuminoid extracts, have found clinical benefits and positive effects on relevant biomarkers at doses deemed insufficient to impact plasma curcumin levels.
Based on this clinical data, the efficacy of curcumin may not be entirely due to the parent molecule but due to its metabolites and degradation products, as well as the other primary curcuminoids. From a clinical perspective, when selecting a curcumin extract, it is therefore important to choose a curcumin preparation which maximally increases these curcuminoids.
It is also likely that a significant proportion of curcumin’s clinical efficacy arises from its action within the gastrointestinal tract, which elicits beneficial effects in peripheral body systems. Evidence suggests that a significant proportion of curcumin’s therapeutic potential may arise from its effect on the GIT specifically through its ability to modulate the microbiome, reduce intestinal permeability and gut inflammation and control pathogenic microbial overgrowth. Curcumin has been found to increase bacterial species diversity in healthy subjects compared to placebo.
Dr Urvi Shah from Memorial Sloan Kettering Cancer Centre is currently conducting the Nutrivention 3 study which is a clinical study comparing the effect of a plant-based diet versus curcumin versus omega 3 on the microbiome of the gut in MGUS and SMM patients – see the below link
The results of this study are eagerly awaited!
Since my studies with MGUS/SMM patients have been conducted using C3 complex curcumin (which contains all 3 curcuminoids) and the clinical studies done by Dr Shah and others are using C3 complex, I am happy to continue to recommend this product to patients. Until other formulations have been trialled in MGUS/SMM patients, it is not possible to make comparisons at this stage.
Dosage, safety and clinical tips
Dosing: The daily dosage of oral curcumin in clinical trials has ranged from 0.2g - 12g daily. High doses have proven safe in a number of clinical trials with limited side effects (such as transient gastrointestinal discomfort). Most commonly, studies reporting positive results have employed doses between 100mg and 4g of either curcumin or mixed curcuminoids.
Timing: There is no clear indication from the literature to date that curcumin needs to be given with or away from food. Theoretically as a fat soluble compound, absorption may be enhanced with a fat containing meal.
Adverse effects: Clinical studies indicate that curcumin is well tolerated with no serious side effects. In a dose escalation trial, single oral doses of 12g were safe, and minor adverse effects including diarrhoea and headache were not related to dose. In another Phase I trial in patients with precancerous conditions or noninvasive cancer, 8g of curcumin daily for three months was well tolerated. Some individuals may experience gastrointestinal upset, such as nausea, abdominal pain and diarrhoea, and require lower doses of curcumin.
Contraindications: Curcumin is contraindicated in bile duct obstruction and caution is advised in gallstones, as a single dose of curcumin (20mg) stimulated gallbladder contraction in healthy volunteers.