In the last twenty years the world of Turmeric has transformed from that cute Indian spice we eat in Garam Masala to a finely tuned global industry.
Thanks to the dietary supplement marketing machine turmeric has become the best selling herbal product in the world, and it doesn’t seem to be slowing down.
Yes Virginia, there is a Turmeric Industrial Complex.
Curcumin: Not Just For Your Centenarian Indian Grandmother
Curcumin is the biologically active ingredient in turmeric and is largely (but not entirely) responsible for curcumin’s health benefits.
It’s a very reactive molecule that performs three main functions within the body:
- It has an alcohol group which serves as an electron/proton donor. (Ie, it’s an anti-oxidant).
- It has a diketo moiety which binds to most metals. (Ie, it’s a chelator or detoxifying agent)
- It reacts with sulfur and selenium containing proteins, which gives it an ability to modify a wide variety of enzymes – most particularly those involved with toxin clearance or free radical reduction. 1
Collectively these capabilities give curcumin an incredibly broad range of biological functions to modify cell growth, the inflammation response and immunity. My ex-Indian girlfriend used to brag about her 103 year old grandmother and how she maintained her vitality due to a special tea she made that contained boiled ginger and turmeric each morning. We broke up due to a mutual intransigence over certain issues, but I’ll finally concede the following point: maybe she was onto something here. (Sorry Jasleen).
The Big Problem
Despite curcumin’s wide range of biological significance using it has a big, puss-filled, pink-elephant-in-the-room sized problem: it’s not absorbed by the body.
In the early 2000’s when the biological functions of curcumin were being clarified a lot of money was poured into stage I clinical trials to develop curcumin compounds as anti-cancer drugs. They were whopping failures.
Because curcumin gets metabolized in such a way that makes it practically impossible to enter your bloodstream. 2
This fact is best illustrated by a clinical trial conducted in 2006 that studied plasma levels of healthy volunteers who took increasingly larger doses of curcumin from 500 mg up to 12g. It was only at the 10g level that the volunteers displayed any detectable level of plasma curcumin, and even then the amounts were trace and well below what would be clinically significant.
So even if you’re taking curcumin by the teaspoonful it’s all but guaranteed to do nothing unless special considerations are taken.
The Next Generation of Suppliers
|Brand||Manufacturer||Organic||Non-GMO||# of Studies w/ Product|
Given the futility of curcumin to enter the body by itself a lot of money has been poured into developing enhanced delivery systems that allow curcumin to pass out of the gastrointestinal tract after digestion. This is accomplished by altering two aspects of curcumin metabolism:
- Inhibiting conjugation. In the stomach curcumin rapidly gets conjugated into two molecules called curcumin glucuronide and curcumin sulphate which pass right through your system and into your stools. If you can inhibit the formation of these conjugates curcumin will stay in your digestive system longer to be absorbed into the bloodstream.
- Enhancing solubility. Curcumin is fat soluble and thus doesn’t readily absorb into gastric juices. If you can put curcumin into some sort of fatty vesicle it can more easily get transported out of the epithelium of the GI tract.
If you can get these details right then the bioavailability of curcumin goes way up (almost 50 fold) and all of a sudden you’re cooking with gas.
So with that being said, here are the five companies who’ve established themselves as the next generation suppliers of Curcumin:
- Sabinsa: They manufacture C3 Curcumin™, which is the oldest, most established brand of specialized curcumin on the market. It was the first of these products to be developed and has the most market penetration and clinical research surrounding its effectiveness.
- Arjuna Naturals: They manufacture BCM-95™ (also known as Biocurcumax™), which is a product similar in scope to C3 Curcumin, with the big difference being Sabinsa curcumin typically uses bioperine as an adjuvant whereas Arjuna Naturals uses a production method that uses essential oils within the turmeric plant as an adjuvant.
- Select Ingredients: They manufacture the Curcupure™ brand of curcumin, which has the distinction of being the only brand of curcumin that’s certified as organic. Of the five suppliers it has the least intellectual property and supporting literature around its product.
- OmniActives: They manufacture the CurcuWin™ extract of curcumin. Like Curcupure™ the amount of supporting studies surrounding it is scarce, with the notable exception of a well-conducted clinical trial that compared its absorption to the other major brands of curcumin that found it to be the highest.
- Indena: They manufacture the Meriva ™ brand of Curcumin, which uses a lyposome to deliver curcumin into the bloodstream, which is a specialized vesicle that stores a molecule inside of a lipid bilayer, making it more accessible to lipid membranes.
The rest of this article is going to compare how well these brands of curcumin are absorbed, how they’re made, what their patents tell us about their production, the clinical studies that test their effectiveness, and how these facts tie into decisions consumers and formulators ought to know about using them in their product.
Hopefully you’re as excited as I am to find this out!
How They’re Made
|CurcuWin||WO2012156979A1||antioxidant + carrier + fatty acid|
One of the better ways to determine the uniqueness of a product is to read through the patents a company has filed around it. They’ll usually cover some combination of its method of production, its composition, its clinical health benefits and how it’s absorbed.
You can think of them as the official determination of their uniqueness. The one document that you can’t use marketing zing to finagle your way out of. Their biggest problem is that since they’re public documents, companies pay IP lawyers big bucks to make them just detailed enough to get them filed but otherwise as vague as possible. They want to prevent competitors from copying them and internet turds like me from airing their trade secrets to tens of thousands of people over the blogosphere.
In any event, let’s discuss the relevant details about each curcumin product vis a vis their patent.
Date filed: July 12, 1996; Filing Company: Sami Chemicals & Extracts, Ltd;
The C3 Curcumin patent has the following unique details about it:
- It makes a claim that its particular blend of curcumin compounds has uniquely potent antioxidant potential
- It makes a claim for the specific composition of its curcumin extract
- It makes a claim for how its curcumin extract is purified
- It does not make any claims about its ability to be absorbed
Patent #US5861415A by Sami Labs can be thought of as the document that started the waterfall cascade of specialized curcumin production. It’s typically referenced by other companies making patented extracts of curcumin when they go to file theirs.
Its method of purification is fairly straight foward, and mostly involves extracting a compound with a solvent, concentrating it, freezing it to get crystals, and then repeating until you get the desired purity and potency.
Moreso than any other curcumin patent the C3 document makes fairly precise statements about the composition of its curcumin product.
Curcumin is actually one compound in a family of compounds called curcuminoids. There are three curcuminoids found in turmeric and it’s generally believed a combination of all three is most advantageous to human health.
The C3 patent determines the relative amount of each curcuminoid within a few percentage points, with curcumin the dominant ingredient at 75-81% of the mixture. This is much more detailed than the other companies, who either make no mention of them at all or give very broad ranges about the composition of their extracts.
However, I think what’s most notable is that the patent makes no reference about the absorption of its product. Absorption is the rate-limiting factor in curcumin’s usefulness, and if we go just by this filing there’s no reason to believe C3 Curcumin is especially well absorbed per se. Of course additional studies have been performed on the pharmacokinetics of C3 Curcumin, but we’ll get to those later on.
Curcupure™ has the least amount of documented information of all the major brands of curcumin. It has no clinical studies to its name and makes the claim of using a patented technology called TrueSorb™ that enhances its absorption but there is little information available on it.
I searched for patents under the TrueSorb name, the company name, and Advanced Nutrisolutions (the company that owns the Curcupure™ trademark) and found nothing.
According to the information on its trademark, TrueSorb uses a process called micro encapsulation, which is when you coat a substance with droplets of some sort of absorbent which increases its solubility.
Sounds fair enough, but given that you can’t find any description about this process on the company website anything I could write about it is hearsay.
There’s scant information on what makes Curcupure™ unique.
Date Filed: May 30, 2005; Filing Company: Arjuna Naturals
The Arjuna Naturals patent goes into how its curcumin extract is produced and, most importantly, its process of blending the extract with turmeric oil as an adjuvant. 3
Because curcumin is lipophilic (fat loving) blending it with an oil increases its ability to pass through the GI tract in a chylomicron 4 after a meal.
The patent then goes on to reference a clinical study that compared its absorbance to a non-prepped curcumin compound. The BCM blend had absorbance values 7x higher.
Date Filed: July 22, 2011; Filing Company: Omniactive Health Technologies;
The Omniactive patent is most unique for its method of improving absorption. Blending curcumin with lecithin or an adjuvant are the most common methods of improving absorption and used by Indena, Sabinsa and BCM to up the bioavailability of their curcumin extracts.
Curcuwin’s manufacturing process blends a purified curcumin extract with an antioxidant (usually vitamin E or ascorbyl palmitate) and then binds it to a starchy carrier like maltodextrin and finally blends it with a fatty acid. The idea behind the technology is to preserve it and then insert it into a nutritional matrix that’ll safety shuttle it throughout the body.
We’ll discuss this more later on in the post but Omniactive conducted a study comparing their curcumin extract with the other premium brands and it showed significantly higher absorption than the others.
Filing Date: March 9, 2006; Filing Company: Indena S.p.A
The Meriva curcumin uses something called a liposome to deliver its curcumin. You can think of a liposome as lecithin+. Since curcumin is fat soluble it needs to be immersed in some sort of fatty medium for it to absorb and cross through the gastrointestinal tract. A liposome engulfs a molecule within a vesicle that has a lipid bilayer that allows it to dock with cell membranes and empty a molecule into and out of a cell.
The unique part of its liposomal process are the specific ratios used by the company to create its blend. It call for a 1:2:2 mix of curcumin:lecithin:cellulose.
Absorption & Composition
Absorption is the bottleneck on curcumin’s usefulness and the key detail that needs to be engineered appropriately for a proprietary product.
The ideal way to measure absorption is with an AUC value (Area Under Curve) that’s computed by comparing the total amount of a compound circulating in the plasma with an intravenous injection compared to an oral dose. It’s the pharmacokinetic equivalent of the double blind placebo controlled clinical trial.
The values in the above table come from this study, which used a well controlled study group to compare the AUC values of the major brands of curcumin, less Curcupure™.
The study was sponsored by the ingredient with the best absorption, which naturally raises some suspicions about the outcome, but for the time being let’s give them the benefit of the doubt since the study itself seems to be well conducted.
C3 Curcumin & Black Pepper Extract – Is It Really The Best?
To me the most interesting value is the absorbance of C3 Curcumin, which was used as the baseline in the study because it was the lowest. That might seem surprising since it’s considered the premier curcumin brand, but it’s not a fluke. Most of the clinical trials done at the beginning of the century used C3 Curcumin as the test compound, and these were the trials that proved once and for all that curcumin isn’t well absorbed.
So C3 Curcumin has been clinically proven not to leave the gastrointestinal tract very efficiently. That’s pretty damning, but the compound’s saving grace is that when you complex it with piperine (black pepper extract) the availability goes way up.
You frequently see C3 Curcumin used with Bioperine™ black pepper extract for this reason. The pairing is so common that it’s become axiomatic that the two must go together.
While the two are immensely more potent when combined, there are good reasons to be suspicious of the piperine/curcumin duo as the standard for curcumin absorption, including:
- All the conventional wisdom about this duo stems from one paper written in 1997, which hasn’t been repeated and has methodological issues, particularly a small sample size of humans.
- Other forms of delivery have been shown to be more effective, particularly lecithin/curcumin complexes and antioxidant/carrier/fatty acid complexes.
- Piperine solves only 1/2 of the bioavailability problem. It blocks the transformation of curcumin into useless metabolites but it doesn’t do anything to improve its solubility. Liposomal curcumin and microencapsulated lecithin probably have better bioavailability results because they improve both.
- The curcumin/piperine ratio used in the study is 10:1, but the ratio used in commercial products is much less than this, usually around 30:1.
There are also lots of C3 Curcumin products which have no adjuvant at all. These are almost certainly poorly absorbed and not very effective.
Mechanistically there’s more reason to put faith in liposomal and fatty acid/antioxidant preparations of curcumin. Empirically there’s more reason to do that as well. Bioperine + Curcumin is a good but easily improved upon method of delivering it.
When it comes to composition the vast majority of curcumin products will be standardized to contain 95% curcuminoids. This is partly due to perceived health benefits, but it’s also become an industry standard that’s done for copycat reasons.
The BCM extract is lower because its production method specifically calls for the use of extra turmeric oil, which is used to increase its absorption. The Meriva extract is much much lower, presumably because the liposomal structure requires a lot of space to port the curcumin molecule inside of it.
From a consumer’s point of view this shouldn’t make much of a difference but from a formulator’s point of view it presents some challenges because it’ll create space constraints if you’re looking to use it with other ingredients in a mixture. If you’re using Meriva inside a capsule you basically have no other choice but to make it the primary ingredient.
Ideally a curcumin mixture is a blend of the three main curcuminoids, and only Sabinsa is precise with the amount it contains of each. If you read through the patents of the others their descriptions of the ratios are vague to the point of being indecipherable.
For example the Omniactives patent says this about its composition:
Curcumin used in the step (i) can be commercially available one with an assay ranging between 85- 96%. It can also be an extract of turmeric rich in curcumin. The amount of curcumin added may be sufficient to produce a water soluble curcumin with an assay of 1-55% curcumin.
The amount of antioxidant used may range between 1-10%.
The quantity of hydrophilic carrier added may range between 10-90%.
Well don’t get too specific guys!
|Brand||Total Number of Studies||Total Number of Clinical Trials|
When a clinical study comes out for a product lots of people get giddy and excited.
“You see guys?! Here it is! Proof that our ingredient rocks, once and for all!”
Personally, I get a little weary because clinical trials can be used for evil just as easily as used for good.
Clinical research is often used as an incantation to make something seem like “magic” to people who don’t know any better. Attaching a journal paper to something can give a product with even the stupidest of claims a veneer of legitimacy.
Lots of research is poorly done, and lots of companies are good at pushing poorly done research through the door to promote their products with a false sense superiority.
So to really understand the significance of clinical studies you need to have a good nose for what they actually mean. Advanced training helps, but there are some simple shortcuts you can take to get the basic picture right 90% of the time.
You need to ask yourself three questions:
- Did the study produce an effective result?
- Was the study well conducted? (Ie, done on humans, control group, placebo controlled)
- Are the results relevant to daily experience? (Ie, what dose and under what conditions were the products taken?)
With those points in mind let’s evaluate what the clinical studies do and do not mean for each extract.
By far and away Sabinsa has the most complete portfolio of clinical studies done on its compounds and it’s the biggest reason it’s the oligarch of the curcumin industry.
Most of the clinical trials done to determine the mechanism of curcumin in the body in the first place were underwritten by Sabinsa so they literally wrote the book on its clinical significance.
It’s very impressive. However, if you read through the list of clinical trials they list on their website there are some important details to keep in mind:
- They were done with doses far higher than what you’d use as a supplement. Most of the studies were done with 2 grams or more of curcumin, sometimes as much as 8. Most supplements have between 250-500 mg of curcumin per serving. Big difference.
- Many of the studies effectively proved the poor availability of curcumin in the first place. So while they did write the book, they also authored some of the chapters that don’t have a happy ending.
- Some of the positive results were done with supplements that contained curcumin blended with other ingredients, particularly Boswellia Serrata, an ayurvedic herb that has anti-inflammatory properties that are complimentary to curcumin. The co-existence of both makes it harder to elucidate how much of the effect was due to curcumin itself.
Arjuna Naturals has the second most extensive portfolio of research around its product, with the important distinction that many of its papers are cell line studies. Cell line studies are useful for determining the mechanism of a compound but say nothing about its clinical usefulness.
There’s a world of difference between pipetting curcumin extract into a cell on a petri dish and a human taking a pill before they go to bed. Chemicals take a long and arduous journey before they reach the target tissues in your body and the amounts of compound pipetted into the cells during the study often swamp any amount you could reasonably take with a supplement. At least not without making yourself extremely sick in the process.
The human trials were generally positive and typically used doses between 1-3 g, which is just out of the reach of what most people would use with supplements.
The most remarkable thing about Meriva’s research is that the doses used with human studies equate to 200 mg of curcumin (1000mg of Meriva since it’s 20% curcumin by weight) which is right in line with what you’d buy in the store. They’re the only curcumin supplier that’s tested their extract at such a low dose and still gotten positive results.
That’s very remarkable and the strongest differentiator it has compared to its competitors. It also has the second best absorption results, giving it a nice 1-2 punch among curcumin suppliers. Discovering a modest benefit with 5g of something is nice, but just not all that practical for you or me if we want it to do something useful for us.
Curcuwin has the most impressive study about its bioavailability which is extremely important because absorption is the biggest bottleneck in curcumin’s usefulness. It also has no clinical research conducted with it, which is the second step in elucidating its usefulness.
Conceivably something that’s well absorbed is also clinically useful, but it’s hard to say exactly what something will do inside the body until you test it. Perhaps the antioxidant used effects its half life in the plasma. Or its affinity for particular tissues. Or something…
This makes a comparison between CurcuWin and its competitors a double edged sword because it dominated in the most important type of study, but has no complimentary research to fill in the cracks. To me this means CircuWin is extremely appealing if it’s price competitive with the other suppliers but perhaps a bit overpriced if it’s the more premium option of the five.
Curcupure has a dearth of IP around its product. The only thing that can easily be found over the internet is its trademark, which doesn’t mean anything for what we’d actually expect it to do inside the body so it’s the clear loser here.
It has the benefit of being certified organic, but organic certification doesn’t mean much if it doesn’t get absorbed by the body. It has a vague statement on its website about what its TrueSorb technology means but there’s no supporting evidence about its effectiveness anywhere else.
I contacted the company about viewing its patent but they didn’t get back to me for this article.
Putting It All Together
All of these curcumin extracts are far superior to a generic curcumin product that doesn’t have a special delivery mechanism. Curcumin without anything else to accompany it is guaranteed to do nothing. If you use C3 Curcumin you need to include piperine with it or you’re just wasting your time. The other extracts have some delivery mechanism built into the product itself.
As a formulator I’m inclined to give a preference to either Meriva or CurcuWin. They have the best combination of proven absorption and/or clinical evidence that’s relevant to supplement users.
Memo to the CurcuWin people: start commissioning those clinical trials! It’s the only thing standing between you and industry dominance.
If any of you need help dealing with the issue of using curcumin in the nutraceutical industry, I can definitely help with that.
Have a nice day!
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An adjuvant is something you add to something else in order to increase its solubility.↩
vesicles that transport fatty compounds out of the stomach after a meal↩