Bitter Compounds—Why We Need Bitter Flavors

Bitter compounds have long been known for their health-promoting effects. As far back as ancient times, bitter compounds were used to treat a wide variety of health problems.¹ For a long time, bitter flavors were not highly regarded, but in recent years, bitter compounds have once again become very popular due to their health-promoting properties.

Bitter is one of the five basic tastes, along with sweet, sour, salty, and umami2. Umami is less well known; it means “delicious” in Japanese and describes a meaty flavor2^{, 3}. We owe our ability to perceive the different tastes to the taste receptors located on the tongue and in the mouth2.

What are bitter compounds?

Bitter compounds are a highly diverse group of chemical compounds that do not have a uniform structure. Their only common feature is their bitter taste. In nature, they occur in many vegetables and medicinal herbs and protect the plant from predators. Typical natural bitter compounds include, for example, phytochemicals and amino acids¹.

Why do we avoid bitter tastes?

Most people do not particularly like bitter foods. This natural aversion is innate: even newborns prefer sweet tastes over bitter ones. This is a protective mechanism of our body, which uses it to shield itself from potentially toxic substances. This is because most naturally occurring toxic substances taste bitter.¹ Sweetness, on the other hand, is considered a “safe taste” because there are no naturally occurring toxins that taste sweet. Instead, we associate sweetness with quick and good sources of energy.

Interestingly, only a single receptor on our tongue is responsible for perceiving sweet and sour tastes. For bitter, however, there are 25 receptors⁴. We therefore perceive bitter much more strongly than sweet, for example. These 25 receptors can detect tens of thousands of different bitter substances⁵—a sophisticated defense system against potentially toxic substances. But not everyone perceives bitterness as equally bitter. Scientists have discovered that how bitter we perceive something depends on our genes⁶.

Over the course of our lives, our innate aversion to bitterness changes as a result of our experiences, and we are able to get used to bitter tastes. Nevertheless, bitter compounds have gradually been bred out of vegetables over the past few decades. As a result, we’ve become accustomed to milder varieties. The good news is that we can also get used to bitter flavors again1.

Why Bitter Compounds?

But why should we get used to bitter flavors? Bitter compounds are currently making a real comeback. And rightly so, because they have a variety of positive effects on our health:

Bitter compounds stimulate saliva production and increase the secretion of stomach acid. In this way, they aid digestion and make food easier to digest.¹ They also stimulate the function of the liver and gallbladder. As a result, the liver produces more bile, which in turn boosts fat digestion and helps the liver detoxify7. Bitter compounds also have a positive effect on bowel function and can thus facilitate the absorption of nutrients8.

Recent studies suggest that bitter compounds can stimulate insulin production in the pancreas. They thus ensure that blood sugar levels, which rise after a meal, drop more quickly, thereby contributing to better blood sugar regulation9^{, 10}.

Bitter compounds can also support weight loss. Unlike sweet or salty foods, which stimulate the appetite for more, bitter compounds suppress the appetite. By binding to intestinal cells, they trigger the release of a hormone produced by the body that signals to the body that it is full9. Bitter compounds can also reduce cravings for sweets in this way.

Many bitter compounds also have antioxidant properties and are capable of activating the immune system⁸^{, ¹¹}.

New findings also show that bitter receptors are found not only in the mouth but in many other body tissues. Researchers have detected them in the digestive tract, the lungs, immune cells, the skin, the heart^, and even in brain cells⁴^{, 12}. Their exact functions in these locations remain largely unclear. However, it is considered established that they are an important component of the innate immune system4.

Natural Bitter Compounds

Bitter compounds are found in many fruits and vegetables, as well as in numerous medicinal plants. In herbal medicine, bitter-tasting plants that have health benefits are referred to as “amara” (Latin for “bitter”)^¹. Amara have been an important part of naturopathy since ancient times. Depending on their properties, they are classified into different categories¹^{, ¹¹}:

• Amara pura (pure bitter substances): Examples of pure bitter substances include yellow gentian, artichoke, dandelion root, and centaury.
• Amara aromatica (bitter substances and essential oils): Plants in this group contain not only bitter substances but also essential oils, such as milk thistle, sage, yarrow, angelica root, hop cones, and wormwood.
• Amara acria (bitter herbs with pungent substances): These medicinal plants contain bitter substances and pungent substances, such as ginger and turmeric.
• Amara mucilaginosa (bitter substances with mucilages): This group includes plants that contain bitter substances and mucilages, such as Iceland moss.
• Amara salina (salt-rich bitter herbs): This group includes salt-rich bitter herbs such as dandelion root and dandelion herb.
• Amara adstringentia (astringent bitter herbs): In addition to astringent bitter compounds, these plants also contain tannins, such as cinchona bark.

Many well-known medicinal plants contain bitter substances that have liver-protective, bile-stimulating, digestive-aiding, appetite-stimulating, and numerous other health benefits. These include, among others:

Bitter Compounds in Well-Known Medicinal Plants

• Milk thistle: Has been used as a medicinal plant since ancient times.¹³ It is considered to protect the liver and help detoxify it.¹⁴^,¹⁵
• Artichoke: Is considered to protect the liver, promote bile flow, and aid digestion. It is also said to have appetite-stimulating, antioxidant, and cholesterol-lowering properties¹¹^{, ¹⁶, ¹⁷}.
• Yellow gentian: Is one of the most bitter ^plants known12. Amarogentin, which is found in the root of the yellow gentian, is even considered the most bitter naturally occurring ^substance12. It has appetite-stimulating, bile-stimulating, and digestive-promoting ^{properties14, 18}.
• Dandelion: Has many different effects: it aids digestion, promotes bile flow, and stimulates the appetite14^{, 19}.
• Peppermint: Known as a medicinal plant for centuries, it offers a surprising number of beneficial effects on the ^body20. Among other things, it promotes bile flow and thus aids digestion14^{, 20}.
• Turmeric: Belongs to the ginger family. It has long been used in traditional Chinese medicine (Pharmawiki). It is said to have bile-stimulating and antioxidant properties14^{, 21}.
• Fennel: Contains the bitter compound fenchone. Known for ^its digestive, antispasmodic, and antimicrobial ^{properties14, 22}.
• Ginger: Contains bitter compounds and pungent substances that give it its sharp flavor. It has antioxidant, digestive, antimicrobial^, and antispasmodic effects14^{, 23}.
• Saffron: Also used as a spice. Contains bitter compounds that ^have antioxidant, anti-inflammatory, and antispasmodic properties24.

These are just a few selected medicinal plants containing bitter compounds that have positive effects on health. Of course, there are many, many others.

Bitter Compounds in Our Diet

In addition to medicinal plants^, bitter compounds are ^found in many fruits, vegetables, and herbs¹¹^{, ²⁵}, though in lower concentrations than in bitter-containing medicinal plants. These foods contain significant amounts of bitter compounds:

• Fruits: grapefruit, lemon, pomelo, kumquat, pomegranate
• Salads: chicory, radicchio, arugula, endive, watercress
• Cabbage varieties: Brussels sprouts, kale, savoy cabbage, broccoli
• Vegetables: radishes, daikon radish, asparagus, fennel, olives, artichokes
• Herbs and spices: thyme, rosemary, chervil, sage, tarragon, bay leaf, caraway, anise, cinnamon, ginger, mustard

How can we incorporate bitter compounds into our diet?

Incorporating more bitter compounds into our diet can be a challenge because we’re no longer used to the bitter taste. However, you can train yourself to like bitter foods. The more often we eat bitter foods, the faster we’ll get used to the taste again.¹

Here are some practical tips to help us consume more bitter substances:

• Experiment with new foods: Incorporate bitter vegetables, herbs, and spices into your meal plan, or start your meal with a small portion of bitter salad or a sip of bitter herbal tea.
• Pair bitter foods with other flavors: Bitter foods often pair perfectly with other flavors to mellow their intense taste. For example, try combining bitter leafy greens with sweet fruits or creamy sauces.
• Add bitter compounds to your favorite dishes: Bitter herbs and spices like thyme, rosemary, turmeric, and ginger can enhance many dishes.
• If you’re unable to incorporate more bitter foods into your meals, you can turn to dietary supplements containing bitter compounds.

Sources

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