Bitter Is Better

"A spoonful of sugar helps the medicine go down." For generations, we have treated bitterness as something to hide. But across the world, traditional medicine has long held the opposite view: that bitterness itself is the medicine. Modern science is now discovering why. The receptors that taste bitterness aren't only on the tongue. They are found in the gut, the airways, the pancreas and beyond.

A taste for danger

Bitterness evolved as a warning. Many poisonous plants taste bitter, so our ancestors learned to approach bitter foods with caution. Humans have around 25 different bitter taste receptors, known as TAS2Rs, compared with just one main receptor for sweetness. That tells us how important bitterness has been to our survival.

But many of the most health-giving compounds in plants are also bitter: the polyphenols, flavonoids, glucosinolates and alkaloids that give plants their protective power. A review in the American Journal of Clinical Nutrition noted that the food industry routinely breeds or processes bitterness out of fruit and vegetables to suit our tastes, and in doing so may remove some of their most beneficial compounds.¹ Modern lettuce, sprouts and even grapefruit are far milder than their ancestors.

Bitter receptors throughout the body

Over the past twenty years, scientists have been surprised to find bitter taste receptors in many parts of the body that never taste food.

• In the gut. Bitter receptors in the stomach and intestines help release hormones that control appetite and digestion. In one study, bitter compounds affected the release of ghrelin, the "hunger hormone", and slowed the emptying of the stomach, helping people feel full sooner.²
• In the nose and sinuses. When bitter receptors in the nose detect chemicals made by certain bacteria, they trigger a defence response: the tiny hairs lining the airways beat faster to sweep germs away, and the cells release nitric oxide, which kills bacteria. People with a less sensitive version of one bitter receptor were more prone to sinus infections.³
• In the airways. Bitter receptors in the muscles of the airways cause them to relax and open, a discovery that surprised scientists who expected the opposite.⁴

Bitter receptors have also been found in the pancreas, heart, skin and immune cells, and researchers are still exploring what they do there.

Bitterness itself is the medicine.

What bitters do for digestion

In Western herbal medicine, bitter herbs have been used for centuries to "wake up" digestion. The moment a bitter taste touches the tongue, it sets off a chain reaction through the nervous system known as the bitter reflex:

• more saliva, to begin breaking down food
• more stomach acid, to digest protein and absorb minerals such as iron, zinc and B12 (See You Are What You Absorb.)
• more bile from the liver and gallbladder, to digest fats
• more digestive enzymes from the pancreas

This is why many cultures begin a meal with something bitter: an Italian aperitivo, a bitter leaf salad in France, or bitter melon in Asia. Clinical trials support the traditional use. Artichoke leaf extract eased the bloating, fullness and discomfort of indigestion,⁵ and a bitter herbal blend containing bitter candytuft has been shown in several trials to relieve functional dyspepsia.⁶

Bitters may also help to tame a sweet tooth. Many people find that a little bitterness before or after a meal quietens sugar cravings. (See Balancing the Sugar Seesaw.)

Bitter herbs

In herbal medicine, bitter herbs are described as cooling and drying. They suit people who tend to feel warm, sluggish and heavy after eating, but may be too cooling for those who are already cold, thin or depleted. (See The Architecture of Balance.) Common bitter herbs include:

• Dandelion root and leaf, a gentle liver and digestive tonic, and free from almost any garden or verge.
• Gentian, one of the most intensely bitter plants known, the classic base of many traditional bitters.
• Artichoke leaf, used for fat digestion and the liver.
• Burdock root, a traditional "blood cleanser" for the skin.
• Chicory root, also rich in the prebiotic fibre inulin.
• Wormwood, very strong and to be used only with expert guidance.

The best herbs for you depend on your constitution and health, so it's wise to seek a practitioner's guidance rather than self-prescribe.

Bringing bitterness back

• Start with salads. Add rocket, watercress, radicchio, chicory, endive or dandelion leaves to your plate.
• Embrace bitter vegetables. Kale, Brussels sprouts, broccoli rabe, cavolo nero and bitter melon.
• Enjoy bitter drinks. Green tea, unsweetened coffee in moderation, and dandelion or chicory "coffee".
• Zest your citrus. Grate orange, lemon or grapefruit peel into food.
• Choose dark chocolate with 70% cocoa or more.
• Try a bitter tincture. A few drops of a herbal bitter on the tongue, or in a little water, 10 to 15 minutes before meals. It needs to be tasted to work, so capsules are less effective.

Our taste buds adapt. Bitter foods that seem harsh at first become pleasant, even delicious, within a few weeks.

At Rootwise, bitter herbs are some of our oldest and most trusted allies for digestion. Often, the simplest place to begin is a handful of bitter leaves at the start of a meal. (For more on digestion and the gut, read The Master Regulator.)