As a Christmas present, my daughter arranged dinner at the world famous Alinea in Chicago.  She and I are both foodies, and after several months of planning, we were finally able to secure reservations. We arrived at the restaurant in the middle of February well before our reservation, so to pass a little time (and stay warm), we hastened to a trendy little café across the street.  Entering the café, I knew that I would stick out among the younger, hip and sophisticated crowd if I ordered my standard- coffee, black, not too hot.  So, I decided that I would jump out of my comfort zone and try something new.  As I approached the barista, trying to hide the fact I really had no idea what I wanted, I spotted the chalkboard:  “Special of the Day”: Turmeric Tea.  Without conscience thought, I blurted out, “Turmeric tea please.”   Almost as if receiving a round of applause for my choice, approving and accepting nods from the barista and patrons alike were directed my way and I felt a sort of relief knowing that I was part of the “club.”  But as relieved as this made me feel, as I stood waiting for this unknown brew to be concocted, I realized that I had no clue what I had just ordered - this was going to be an adventure, but one I was glad I took. 

The turmeric tea was delicious- it had a gentle, warm spicy taste to it.  Its semi-sweet aroma made me feel alive (perhaps the placebo effect), but no matter, I was hooked!  When I got back home, I was determined to read up on turmeric to find out what it was all about - and to figure out how to make the tea myself.

As it turns out, turmeric is rather popular topic these days.  What I learned was that turmeric is an everyday go-to spice used by billions of people throughout India and Mideast.  It is the major constituent of curry powder and gives many of their dishes a spicy dash and golden yellow color. For centuries, it has been a mainstay of ancient Ayurvedic medicine practiced on the Indian subcontinent and used for gastrointestinal discomfort, pain, arthritic inflammation and other ailments.  What I also found was that the chemical constituents within turmeric - curcumin and related curcuminoids - were at the center of a debate between the medical and pharmaceutical communities.  On the one hand, curcumin had gained notoriety as an alternative medicine based on its potential to counteract many diseases caused by the Western Diet.  It’s wide use throughout India and the Mideast has led many to believe that the lower prevalence of hypertension, obesity, diabetes, Alzheimer's Disease, gastrointestinal and mental health disorders in this geographical region supports the notion that chemical agents within turmeric could be viable pharmaceuticals targets capable of counteracting many Western World ailments.  Indeed, over the past 15 years, more than 1000 scientific reports have been published, (here's a nice one) and scores of randomized human trials have been conducted confirming the association of curcumin and human health.  

On the other hand, medicinal chemists within the pharmaceutical firms had reached their wits end trying to package curcumin’s therapeutic benefits in the form of an easy to swallow pill.  At the root of their concern was the fact that curcumin is not bioavailable.  (A successful drug candidates must be able to dissolve and distribute itself throughout the body-usually via the bloodstream- to affected parts of the body.)  Curcumin has low systemic bioavailability; it is marginally soluble in water and any that does happen to get into the bloodstream is rapidly metabolized and eliminated.  Analysis of the blood serum levels of curcumin after oral dosing in both animal and human studies indicate that maximal achievable concentrations are well below those required to cause a measurable pharmacological effect.  In some cases, curcumin is not detected at all!  How could this possibly be a drug?

Despite the loss of heart for curcumin among medicinal chemists, the confounding reality is that it does prevent, eliminate and decrease the progression of many disease states.  Could the problem of its low bioavailability actually be the solution in providing a rational explanation of how curcumin works?   Considering that more than 90% of the curcumin ingested passes thru the digestive tract unscathed and ends up in the large intestine and colon, which is the home of our gut microbiome, it’s a possibility.

There are about 1000 microbial species that reside in a healthy gut.   In animal and human studies, oral intake of curcumin changes the gut microbiota in a very profound way.  The overall populations of microbial strains known to cause “leaky gut” and to promote pro-inflammatory pathways leading to Western Diet diseases are diminished.  At the same time, microbial strains associated with promoting gut health and anti-inflammatory pathways are enriched.  The typical microbial profile indicative of a high sugar/high fat/low dietary fiber diet (i.e. Western diet) cannot be established when accompanied with dietary curcumin.  Instead, the microbial populations are similar to healthy guts promoted by lean, plant-based diets.  Clues as to how this may occur is currently being worked out, but since many of diseases shown to be impacted by dietary curcumin have chronic systemic inflammation as a common factor, it may well be that curcumin’s mechanism of action is as simple as restoring a healthy gut as suggested in this study.

Wait, there may be More!

In a recent study, the genetic analysis of gut microbiota enriched by dietary curcumin demonstrated that a number of microbial strains possessed the means to metabolize curcumin directly by a so-called “curcumin converting enzyme.”  Curcumin metabolites, distinctly different than those generated by our body’s metabolic pathways were identified and possess inhibitory effects on known pathways of Western world diseases mentioned previously.    

Curcumin, easily and safely added into our body through diet, capable of passing thru the gauntlet of our digestive system, and made available to awaiting microbes suggests a scientifically rational approach to explain how other exotic spices and food additives with low bioavailability may confer their health benefits   In what may be termed “Biome-Medicinal Chemistry,” we may be able to bio-hack our biome by fortifying selected microbial strains known to act upon these “pro-drugs” to produce a very specific set of health promoting metabolites. (see this review✎ EditSign)

Little did I know that something as simple as ordering tea could pique my interest in such a topic.  As I write this, I am sipping my homemade version: freshly ground turmeric and ginger with a dash of cinnamon and cardamom.  It is every bit as delicious as my first cup I had in Chicago.  And by the way, many thanks to my daughter for a lovely dinner – Alinea is highly recommended and well worth the wait!