Quick question: What’s your favorite food? If you thought of something sweet or starchy or high in fat—or maybe even all three—that’s no accident. In fact, it’s what you’re wired to love.
Back when humans had to forage and hunt for meals, the goal of eating wasn’t enjoyment. Instead, it was to load up on as many calories and to get as much energy as possible. Game was tough to capture, and humans’ GI tract can’t digest unprocessed grains. So the majority of our diet was made up of easy-to-find plants — wild fruit and bitter barks, roots, and tubers — and bird and reptile eggs.
Flash-forward to today, when humans forage in the grocery store and find our food on restaurant menus, and it’s the calorie-packed sweet, starchy, and fatty foods we want to eat most. “We’ve selectively taken all the bitter out of our diets, especially in the last 100 years or so, as people have shifted from eating mostly vegetable matter to a grain- and meat-heavy diet,” says Dr. Bill Rawls, MD, medical director of Vital Plan.
That means, for many, their bitter taste receptors essentially go unused. It wouldn’t be a big deal if all those receptors did was tell your brain you’re eating kale, not cake. But bitter receptors actually play an important role in healthy digestion, appetite, and more.
In fact, we have bitter taste receptors not only on our tongue, but throughout the digestive system, and on other organs like the pancreas. Fun fact: There are 25 different receptors for bitter in the gut alone, while only one each to detect sweet and umami compounds.
“When something bitter hits your mouth, it sends a signal that primes your GI tract for action,” explains Dr. Rawls. “Receptors in your gut then stimulate production of enzymes that break down food, the churning action of the stomach, and movement in the GI tract. But we’re mostly missing that stimulation now.” The result? Digestive issues, carb cravings, weight gain—and all the health problems that can come with it.
The good news? Waking up those often-ignored receptors can help support healthy digestion and regulate other eating-related issues and functions. Here are three ways that getting a little more bitter can benefit you, plus how you can take advantage of that.
1. Enjoy smooth and healthy digestion
The taste receptors in your gut have a direct line to hormones involved in digestion and metabolism. Research shows that activating bitter taste receptors in the gut triggers the release of CKK — or Cholecystokinin, a hormone secreted in the upper part of the small intestine.
It’s CKK’s job to tell the pancreas and gallbladder to send in enzymes and bile that are essential for breaking down food into usable parts. CKK also regulates movement of food through the GI tract and gastric emptying. Meanwhile, additional research has found that stimulating bitter taste receptors may also facilitate digestion by impacting blood flow and the smooth muscle of the GI tract.
Given all that, it starts to become clear why ignoring your bitter taste receptors can cause digestion to go haywire. And that’s exactly what our traditional Western diet—which is full of meat and refined grains, and devoid of bitter—is doing, says Dr. Rawls. “Without those signals, you end up with a lump of dry food in your stomach.”
Our modern diet is also low on the natural water content that’s found in vegetables and fruit and normally assists in moving food through the body, notes Dr. Rawls. “So you get thirsty and down a 20-ounce drink, which then dilutes the stomach acid you do have, and washes out any digestive enzymes,” he explains. “Once again, the food sits, stomach acids bubble, the lining of the stomach gets irritated, and it’s a mess all the way down the pipe from there.”
That’s likely why bitter plants, herbs, and extracts have been used for centuries in traditional medicine to aid digestion and treat its problems. Researchers are now starting to catch on and shed light on the science and effects. One research review published in the International Journal of Food Sciences and Nutrition, for example, reported that the bitter artichoke leaf extract improved symptoms of indigestion, including bloating, stomach pain, gas, and more, in 70-85% of subjects.
2. Control your cravings and hunger
Bitters are believed to help squelch cravings, and recent research suggests it might be due, at least in part, to taste receptors’ influence on hormones.
For instance, stimulation of bitter taste receptors in the gut has been shown to trigger the release of PYY and GLP-1, two hormones that control appetite and food intake. That action may potentially help you feel fuller and satiated longer, according to research published in the journal Proceedings of the National Academy of Sciences of the United States of America.
Other, preliminary studies offer more support of bitters’ ability to control hunger. Subjects in one small study who took capsules of a bitter compound an hour before an all-you-can-eat meal consumed fewer calories than when given a placebo, according to findings published in the Journal of Neurogastroenterology and Motility. They also had higher levels of the digestion-helping hormone CKK.
Finally, a study published in the British Journal of Nutrition, looked at what happened when people ate a pudding containing the bitter gentian root extract for breakfast. (The root was encapsulated to mask its flavor in the mouth, but not in the gut). What it found: Participants consumed 30 percent fewer calories in the hours after lunch.
Though more research is needed to understand the “why” behind all of these findings, the ability of bitters to help keep our penchant for high-calorie carbs and sweets in check certainly shows promise.
3. Promote blood sugar balance
Bitter herbs have long been used in traditional medicine to support healthy blood sugar levels. Which makes sense when you consider that the pancreas, which makes insulin — the hormone that regulates blood glucose levels — contains bitter taste receptors.
While there are likely several factors at play, one may be the ability of bitter taste receptors to initiate the secretion of the hormone GLP-1. Not only does GLP-1 work to regulate appetite and food intake, it also stimulates insulin release and helps keep blood glucose levels steady. Consider this one more way bitter foods and herbs may help support a healthy metabolic system.
Simple ways to get more bitter
Thankfully, you needn’t start foraging in the backyard for roots or gnawing on bark like your cave-dwelling ancestors to introduce more bitter elements to your life. Instead, try the following, more enjoyable tips.
• Eat more plants
This one is easy and essential, says Dr. Rawls. “Half your plate should be filled with vegetables.” Most veggies naturally contain more bitter substances, tipping your diet in the right direction. For best results, include those that have a stronger bitter flavor, such as kale, arugula, spinach, radicchio, dandelion greens, and broccoli.
• Look for bitter herbs in supplements
“When you look at herbal therapy today, it’s comprised of leaves, stems, barks, roots — all the bitter things that people used to eat when they foraged for food,” says Dr. Rawls. Most of these bitter herbs offer additional, complementary benefits, too. For example, if it’s healthy digestion you’re after, look for berberine, a bitter compound from various shrubs and plants, and andrographis, a plant native to India that helps support bacterial flora in the gut. Gentian, dandelion, and burdock root are also bitter herbs that support liver function and digestion.
• Take a bitter aperitif
Aromatic bitters (bitter herb extracts in an alcohol base) have become a popular ingredient in craft cocktails, but you’ll get more bang for your bitter by squeezing a dropperful or two on the back of your tongue before every meal. “While there’s evidence that swallowing capsules with bitter herbs activates the bitter taste receptors, it’s still a good idea to get that full response by actually tasting the bitter,” Dr. Rawls says. Look for bitters that contain herbs known for helping digestion. That includes burdock, dandelion, and gentian root, as well as fennel seed and ginger.
The best time to start working more bitters into your diet? Now. Research suggests your ability to detect bitter may decline with age, but also that the more you exercise those bitter taste receptors, the more you may experience the benefits. So start today, and enjoy the benefits of bitters for many years to come.
Discover more in Dr. Bill Rawls’ new #1 Bestselling book: The Cellular Wellness Solution: Tap Into Your Full Health Potential with the Science-Backed Power of Herbs.
1. San Gabriel, Ana M. “Taste receptors in the gastrointestinal system.” Flavour 2015 4:14.
2. Sternini, C. “Taste receptors in the gastrointestinal tract. IV. Functional implications of bitter taste receptors in gastrointestinal chemosensing.” Am J Physiol Gastrointest Liver Physiol. 2007 Feb;292(2):G457-61.
3. Depoortere, Inge. “Taste receptors of the gut: emerging roles in health and disease.” Gut. Volume 63, Issue 1.
4. McMullen, Michael. “Use of Bitter Herbs in Practice.” Int J Complement Alt Med 2017, 6(5): 00198.
5. McMullen, M. et al. “Bitters: time for a new paradigm” Evidence-Based Complementary and Alternative Medicine, Volume 2015.
6. Valussi, Marco. “Functional foods with digestion-enhancing properties.” International Journal of Food Sciences and Nutrition, 2011.
7. Madisch, A. et. al. “Treatment of functional dyspepsia with a herbal preparation. A double-blind, randomized, placebo-controlled, multicenter trial.” Digestion. 2004;69(1):45-52.
8. Janssen, Sara, et. al. “Bitter taste receptors and α-gustducin regulate the secretion of ghrelin with functional effects on food intake and gastric emptying.” Proc Natl Acad Sci U S A. 2011 Feb 1; 108(5): 2094–2099.
9. Andreozzi, Paolo, et. al. “The Bitter Taste Receptor Agonist Quinine Reduces Calorie Intake and Increases the Postprandial Release of Cholecystokinin in Healthy Subjects.” J Neurogastroenterol Motil. 2015 Oct; 21(4): 511–519.
10. Mennella I, et. al. “Microencapsulated bitter compounds (from Gentiana lutea) reduce daily energy intakes in humans.” Br J Nutr. 2016 Nov 10:1-10.
11. Obara, K. et. al. “Isohumulones, the bitter component of beer, improve hyperglycemia and decrease body fat in Japanese subjects with prediabetes.” Clinical Nutrition 28 (2009) 278–284.
12. Suh, HW, et. al. “A bitter herbal medicine Gentiana scabra root extract stimulates glucagon-like peptide-1 secretion and regulates blood glucose in db/db mouse.” J Ethnopharmacol. 2015 Aug 22;172:219-26.
13. Holst JJ “The physiology of glucagon-like peptide 1.” Physiol Rev. 2007 Oct;87(4):1409-39.
14. Yu, Y. et. al. “Berberine induces GLP-1 secretion through activation of bitter taste receptor pathways.” Biochem Pharmacol. 2015 Sep 15;97(2):173-7.
15. Pham, Hung et. al. “A bitter pill for type 2 diabetes? The activation of bitter taste receptor TAS2R38 can stimulate GLP-1 release from enteroendocrine L-cells” Biochem Biophys Res Commun. 2016 Jul 1; 475(3): 295–300.
16. Palatini, K. et. al. “Diverse Classes of Bitter Phytochemicals Modulate Carbohydrate Metabolism and Immune Responses through Gastrointestinal Bitter Taste Receptors.” The FASEB Journal. Published Online:1 Apr 2015 Abstract Number:405.5 Supplement.
17. Dotson, Cedrick D. et. al. “Bitter Taste Receptors Influence Glucose Homeostasis” PLoS One. 2008; 3(12): e3974.
18. Cicero AF et. al. “What do herbalists suggest to diabetic patients in order to improve glycemic control? Evaluation of scientific evidence and potential risks.” Acta Diabetol. 2004 Sep;41(3):91-8.
19. Palatini, K. et. al. “Diverse Classes of Bitter Phytochemicals Modulate Carbohydrate Metabolism and Immune Responses through Gastrointestinal Bitter Taste Receptors” The FASEB Journal. Published Online:1 Apr 2015. Abstract Number:405.5.
20. Chen, Hongdong, et. al. “Application of Herbal Medicines with Bitter Flavor and Cold Property on Treating Diabetes Mellitus” Evidence-Based Complementary and Alternative Medicine Volume 2015, Article ID 529491, 7 pages.
21. Santa-Cruz Calvo, Sara and Josephine M. Egan. “The endocrinology of Taste Receptors.” Nat Rev Endocrinol. 2015 April; 11(4): 213-227.