What is curcumin bioavailability?
To understand what bioavailability is and why it is essential, we need to dive into the world of words—etymology. Etymology is the study of the origin and meaning of words. Without the meaning of words, we have no language. Without language, we have no way to communicate. Just look around us in society today. People talk, talk, and talk right past each other. We talk, we text, we email, we emoji, but we don’t communicate. LOL. In history, never have humans said so much yet communicated so little.
Let’s play some word puzzle! The word bioavailable is the combination of two words, bio and available. Bio is from the Greek word bios which can be translated as life and is short for biological. Available is the combination of two additional words: avail and able. Avail is to provide benefit or help, and able means to be capable. Combine the three (bios + avail + able), and bioavailable is a substance or something ready to benefit or help biological life.
Bioavailability primarily applies to just the oral delivery route. The intravenous delivery route bypasses most issues that negatively affect bioavailability, which involves the oral delivery of food, supplements, herbs, nutraceuticals, and medications. By definition, bioavailability is the oral intake of a biological substance that must migrate and mitigate its way through the gastrointestinal tract, then be absorbed in proper amounts and delivered throughout the body to elicit a significant biological effect on life. In short, bioavailability is about gaining access to systemic circulation from oral delivery. Also, don’t lose sight of the point that bioavailability can be for good, to promote healing, health, and life; or for bad, promoting poor health, dis-aise, and destruction.
Why is bioavailability important?
Bioavailability seems simple enough, but some of the smartest amongst us miss its simplicity and importance in biology. Take the bioavailability of vitamin C, for example. This lesson goes back to the father of vitamin C (Linus Pauling) and the Mayo brothers in the 1970s and 1980s. In short, Linus Pauling showed that intravenous vitamin C prolonged the life of patients with terminal cancer. The life extension benefit provided by intravenous vitamin C was 300 days. Let me repeat that to drill that into your memory; the addition of low-dose intravenous vitamin C extended the life of terminal patients by one year. More, it improved the quality of life over that same time as well. Hmmm. In stepped the Mayo brothers, founders of the prominent Mayo Clinic. The Mayo brothers wanted to reproduce Pauling’s work. They took the same dose of vitamin C (10 grams) that Linus Pauling used in his studies intravenously but instead gave it orally to terminal cancer patients. The result is they found no benefit in survival. Surprise? The Mayo brothers reproduced the patient population, therapy, and dose, just not the delivery method. Was this intentional, or was this simply a lack of oversight? We will never know. The difference is obvious: intravenous versus oral delivery of vitamin C results in different systemic delivery and different effects. The difference comes down to bioavailability. Not a surprise, the work of the Mayo brothers became the rallying cry against vitamin C by conventional medicine, and Linus Pauling was ostracized and marginalized. Unfortunately, this lack of understanding permeates conventional medicine like a bad cough that will not go away. The Mayo brother’s miscalculation has led to a complete misunderstanding of the benefits of vitamin C in cancer patients that continues even today. More, it has created two groups pitted against each other over a misunderstanding of bioavailability, but most don’t realize and know the foundational dispute. As a result, patients suffer due to physicians’ lack of understanding of the concept of bioavailability. To read more specifics, check out my previous post on vitamin C and cancer.
But, why is bioavailability significant? It is about results! The different effects of Linus Pauling’s research and the Mayo brothers is the proof in the pudding. Suppose a physician, medical provider, or patient wants to get the full anti-cancer benefits I highlighted in the previous blogpost on curcumin (link to next post). In that case, it must be dosed and delivered correctly to maximize the full biological healing benefit, affected by bioavailability, of curcumin. Only through the understanding and leverage of curcumin bioavailability can this goal be achieved.
Bioavailability is a measure of pharmacokinetics. Pharmacokinetics is the pharmacological study of the absorption, systemic distribution, metabolism, and elimination of a substance. The conventional mindset in the study of pharmacokinetics is related to the study of drugs. However, pharmacokinetics also applies to all things—including natural curcumin.
History repeats itself
The same bioavailability confusion is evident in the oral and intravenous delivery of curcumin. History and truths have a way of repeating themselves. A study published in 2017 showed that the intravenous delivery of curcumin, dosed at 10 mg/kg, yielded a maximum blood serum curcumin level of 0.36 (+/- 0.05 μg/mL). In contrast, a 50 times higher oral concentration of curcumin yielded a maximum of only 0.06 (+/- 0.01 μg/mL) blood serum curcumin level . Let me restate this to make it clear, a 500 mg/kg dose of oral curcumin, compared to 10 mg/kg through intravenous administration, resulting in a maximum curcumin blood serum concentration of only 0.06 μg/mL versus 0.36 μg/mL. That is a six-fold reduction in curcumin plasma levels. More than the six-fold plasma level difference is the upside-down 50 fold increase in oral dose to yield that six-fold decrease in plasma levels—not much bang for the buck. But what about humans? The highest plasma levels of curcumin I can find documented are from a 2006 study where 0.051 mg/ml was documented from a whopping 12 grams orally . That is the power of poor oral bioavailability. For reference, the readily agreed upon historical bioavailability of curcumin is 1%1. In contrast, the bioavailability of intravenous curcumin is 100%. This problem is not a new discovery. The same problems with bioavailability and differences in delivery via oral, intravenous, or intraperitoneal curcumin bioavailability has been shown repeatedly    since the late 1970s. This is the Linus Pauling, and Mayo brothers debate all over again, just this time with curcumin. Again, history has a way of repeating itself.
This blog post is not about vitamin C but is about curcumin. Broadly, the bioavailability of curcumin comes down to:
- Intrinsic curcumin effects
- Absorption of curcumin
- Curcumin metabolism and metabolites
- The rapid elimination of curcumin from the body
Specific to oral curcumin, the poor bioavailability of curcumin comes down to:
- Low solubility
- Gut integrity
- Gut microbiome
- Poor GI absorption
- Hyper-metabolism (breakdown) of the curcumin compound
- Rapid elimination of curcumin from the body
- Poor systemic delivery of curcumin
The poor bioavailability of curcumin has little to do with the lack of intrinsic effects. The intrinsic effects of curcumin are not open for debate, and the science is apparent on the biological effects of curcumin. It comes down to delivery. The lack of intrinsic effects results from the lack of optimal delivery—the Mayo brothers effect.
What is the answer to curcumin bioavailability?
This question is easy, and I hope you already see the answer. Linus Pauling, in the vitamin C bioavailability debate, identified the solution. It is all about intravenous delivery—this time with curcumin instead of vitamin C.
The GI tract of most people in the world today is an absolute, unmitigated disaster! The damage we have done to what God created is very disappointing, but history is full of these copy-and-paste examples. As a result, the gut can not be counted on for the proper delivery of curcumin, vitamin C, quercetin, or nutrition, for that matter, to the body. The gut is key to bioavailability. Through the bypassing of the gut, intravenous curcumin is the only answer that can deliver the full healing, anti-cancer potential of curcumin.
The oral route is not and should not be considered a lost cause in this effort. The oral delivery of curcumin will provide some support to systemic levels and effects. Still, it is not the answer to achieve the systemic levels required to target cancer on the massive scale necessary to heal the body of cancer. We also must improve the integrity of the gut, which is easier said than done. In many ways, the gut is the origin of potential dis-aise or health. For example, inflammation that is the result of gut dysbiosis (imbalanced gut bacteria) is associated with, and likely a significant contributor to the cause of diabetes-called metabolic endotoxemia   . Metabolic endotoxemia, gut dysbiosis or poor gut microbiome health has been shown to contribute cancer       , impact cancer treatment     , contribute to autoimmune disease , contribute to cardiovascular disease  , and beyond. The gut and gut microbiome impact on dis-aise and health is incalculable, and I propose foundational, but that is a discussion for another time.
How to overcome the poor oral bioavailability of curcumin?
A few things can be done to increase gut absorption and increase oral bioavailability, better added to curcumin. These options are evident in a lot of the commercial curcumin products on the market today. They include liposomal preparations, nanoformulations, piperine, silibinin, and quercetin. The liposomal preparations attempt to improve the absorption, and the nanoformulations attempt to improve the solubility. I will not touch on them here in this post. Silibin and quercetin alone have their anti-cancer benefits. But here, the addition of silibinin, quercetin, and piperine, inhibits the metabolism breakdown of curcumin. The result is an increase in bioavailability—systemic delivery.
Despite these advances in delivery and effects on bioavailability, the yield is still, well…less than optimal. Take piperine, for example. The addition of piperine increases the bioavailability of curcumin by 2000% ! That is dramatic. If the bioavailability of curcumin is 1%, then that must yield 2,000% right? The specifics tell a different story. Take the most common curcumin over-the-counter oral dosage, 500 mg, for example. If the bioavailability of curcumin is known to be 1%, then only 5 mg of the 500 mg is available for systemic effects. The result is not much and definitely not enough to impact the broad dysfunction of cancer or other diseases. According to the study, the addition of piperine increases bioavailability by 2,000%. In absolute numbers, a 2,000% increase in 5 mg yields only 105 mg. That is a definite increase, but not by much. This increase is not enough to tap into the full anti-cancer effects of curcumin. Whether in cancer, autoimmune disease, or to maximize healing and health, the intravenous delivery of curcumin is the only way to unpack the full healing potential of curcumin.
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Dr. Nathan Goodyear is dedicated to disease prevention, disease resolution, and the Wellness Lifestyle through a solution-based, Integrative Medicine approach founded in science. Dr. Goodyear received his Bachelor of Arts from Louisiana Tech University and his Doctor of Medicine from LSU Health Sciences Center.
He is Board Certified in Obstetrics and Gynecology and served as the Chief Resident in Obstetrics and Gynecology at the University of Tennessee. Dr. Goodyear has practiced Integrative Medicine since 2006. Dr. Goodyear is a Fellow in Functional and Regenerative Medicine and served on the board of the American Functional Medicine Association. Dr Goodyear is licensed by the Arizona Homeopathic and Integrative Medical Board in the State of Arizona. Dr. Goodyear is a published author, Man Boob Nation–an Integrative medicine approach to low Testosterone published in 2014, and Total Testosterone Transformation published in 2017