Truth can be stranger than fiction. This is one of those moments. Everyone knows that we have taste “buds” in our mouths. These are actual taste receptor proteins, and though discovered in the early 2000s, we now also know that they exist outside of the oral cavity. Here is where it gets weird. We have taste receptor proteins in multiple tissues and organs all over our bodies! Particularly, type II taste receptor cells can detect the difference between both bitter and sweet, thus linking these two opposites with respect to the signaling pathways they initiate. Taste receptor proteins like these are called G-coupled protein receptors (GPCRs): proteins that live on cell surfaces and detect the immediate environment in which the cell is bathing. These GPCRs have an oscillation-type frequency when they bind with a ligand that creates a message received by the interior of the cell on the other side of the cell membrane. At least that is how Jeffrey Bland, PhD explained it at this year’s Integrative Healthcare Symposium, and the image really made sense. The substance never has to enter the cell to be detected or trigger a response. Back to the fact that, in these type II GCP taste receptors, both bitter and sweet “shaped” molecules can be detected, but they trigger a cascade of completely opposite actions. Quite easy to imagine, it comes as no surprise that the “sweet” ligand triggers certain metabolic events that cause us to accumulate, while the “bitter” ligand triggers metabolic “cleansing” activities. Where can we find these now seemingly ubiquitous bitter and sweet taste receptors? Finding them in the ovaries has made a big splash in the treatment possibilities for PCOS—polycystic ovarian syndrome—characterized by both irregularities in fatty tissue metabolism and insulin resistance that lends a two to six times higher risk of developing type II diabetes. They have also been discovered in the pancreatic beta cells, liver, lungs, small intestine, adipocytes and even macrophages. Surprised? Intrigued?
What is quite fascinating is that this research—which is ongoing, and more compounds that can target these receptors are being discovered at this moment—confirms what both ayurvedic and Chinese medicine have known and suggested for millennia. Bitter taste lowers blood sugar, “scrapes” fat off of tissues by causing the body to metabolize it, increases the metabolism while decreasing the appetite, shrinks tumors and growths, is anti-bacterial and anti-fungal, is anti-inflammatory, and is found in herbs that reduce fatty tissue and support weight loss. In ayurveda, bitter taste is composed of the elements ether and air, and so it is very cooling, light, dry and subtle. It is employed therapeutically to purify and dry secretions, tone and tighten tissues, decrease the appetite in high amounts or normalize in small amounts. It can be emetic in large quantities, and can reduce digestive problems, fever, liver and skin irritations. Examples of such herbs are any bitter and leafy greens like endive and dandelion, herbs like gentian and golden seal, bitter melon (well known to be used for hyperglycemia), the “sugar-destroyer” shardunika or Gymnema sylvestre, and even in bitter roots like the ever popular turmeric.
Now, both hops and turmeric have been investigated for their ability to activate these receptors in various tissues, but especially the intestinal cells, ovaries and adipocytes. A hops derivative called humulone, usually converted to more bitter derivatives during the actual fermentation into beer, is the basis for a relatively new drug by Kindex Pharmaceuticals, called KDT501. This substance has undergone both animal and human trials and has been found to improve fatty liver and liver inflammation, blood glucose, insulin function and blood triglycerides and lipids. It has also improved testosterone and fertility/cyclicity in preclinical studies. In the ileum, glucagon receptors were found to be best antagonized by curcumin from turmeric, signaling the release of less glucose into the bloodstream and showing promise as a treatment in type II diabetes and insulin resistance. This research and the implications are inspiring and promising.
It is quite important, though, that we not get too caught up in reductionist thought, waiting for the next discovery, when it has already been well demonstrated that we humans in modern society and in industrialized countries have much higher risks of diet- and lifestyle-induced metabolic diseases as a result of our craving for the sweet taste. Now we know that we are over-activating GPCRs in multiple systems by favoring this sweet taste and no longer balancing the tastes in our diets. Ayurvedic medicine calls for the balance of six tastes in the diet to maintain health: sweet, salty, sour, bitter, astringent and pungent. Chinese medicine utilizes a description that is pleasant, savory and “meaty,” called umami. But both systems recognize that taste can be both harmful and therapeutic, depending upon how it is balanced. Each person’s individual constitution calls for a different balancing of these tastes; no one person requires the same ratios and may even shift their needs depending upon their health status. So even as we have learned in integrative medicine to “prescribe” a diet rich in leafy greens in cases of obesity, insulin resistance, metabolic syndrome, diabetes, heart disease, liver inflammation and gall bladder or bile disorders, the therapeutics of taste can be employed even more specifically as we work with our patients utilizing herbal extracts, novel nutraceuticals and even newly patented drugs derived from these herbals used for millennia.
It is an exciting time with all the ongoing research on herbs, foods, fungi and the components of these long-consumed foodstuffs. Cannabis, hops and turmeric contain enough promising compounds to keep research institutions busy for decades to come. It is enticing to lean in the direction of clinically proven components of these plants that can target specific receptors in the human body, elucidating the exact mechanisms by which they can trigger a cellular response and a cascade of metabolic events. At the same time, we continue to have at our disposal thousands of years of applied human population research in the herbal pharmacopeia of which we can safely take advantage. We can shift our patients’ diets in the direction to rebalance the therapeutics of taste, utilize safe herbals and potent foods to offer additional supports, and in the process perhaps teach our patients to reclaim the concepts of traditional diets which took these therapeutics into account somehow instinctively. Looking at the combinations of foods in each of the five documented Blue Zones—but especially Sardinia, Ikaria, Nicoya and Okinawa—we can easily model healthful eating patterns after their long-standing culinary wisdoms. And, as is becoming necessary in today’s environment of excesses, if a patient just won’t adjust their diet or take their herbs and spices, we now have a pill for that.
Amber Lynn Vitale has practiced as a certified nutritionist, ayurvedic specialist, advanced bodyworker and yoga therapist since 1996. Much of her nutrition practice was in collaboration with functional medicine doctors and other integrative practitioners. Since 2008, she has also produced written and video educational content for many publications, as well as for her own clients and an interested public audience. By 2012, she had realized that raw materials sourcing, labeling transparency, legitimate certifications and educational support were the criteria that would set quality natural products companies apart from others; and she made it her mission to educate the public on the importance of education before supplementation. In 2014, she became the Northeast regional educator for Garden of Life and continues to write, lecture and produce online content on health and wellness topics important to the practitioner and the patient alike.