Nutrition tip: Bitter substances
Nutrition tip: Bitter substances
What would the Oktoberfest be without beer? What would a beer be without bitterness? It is a flavour associated with both pleasure as well as aversion, depending on one’s food and flavour preferences. In this nutrition tip we explain the fundamentally positive effects of bitter substances in the body. (Foto: ©Inge Knol)

Protection against bugs

Since the early days of agriculture and animal husbandry, man has tried to protect the plants in his environment, because they are safe to eat and they taste good too. The plants defended themselves with thorns, hard barks and bitter substances. Nowadays, pesticides and herbicides have taken over these tasks to ensure higher and faster yields.


Humans have around 25 bitter taste receptors on the tongue. The aversion many people have to very bitter food is thought to be a legacy from our early days to ensure survival, since poisonous plants usually have a very bitter taste. The brain responds with a gag reflex.

Niche status

Although bitterness is today usually no longer considered to be a warning sign, man’s taste preferences have remained the same. Particularly in the Western industrialised nations, preference is given to what is sweet or salty. In processed foods, there are often flavours and additives that satisfy both tastes equally. Furthermore, bitter substances were deliberately bred out of food crops. This applies to fruit and vegetable varieties and partly to traditionally tangy artichokes, salads such as radicchio, rocket and chicory.


Foods that contain bitter substances: Artichoke leaves, chicory, endive, broccoli, Chinese cabbage, dandelion, nettle, celery, kohlrabi, chamomile, cinnamon, rhubarb, grapefruit, pistachios and bitter chocolate.
Wild plants contain more bitter substances than cultivated plants, since they have to stand out in nature against wind, rain, sun exposure, pest infestation and hungry animals.

Beverages that contain bitter substances: Coffee, beer, Campari, herb bitters (Swedish bitters)


Good for digestion
Bitter substances stimulate the digestion because they ensure the fast flow of digestive juices. Cynarin is, for example, the bitter substance found in artichokes, while terpene and polyphenols can be found in nettles, dandelions and rocket. When they come into contact with the mouth’s taste receptors, the stomach, bile, liver and pancreas are stimulated to produce saliva and digestive juices. Heartburn, flatulence or bloating occurs less or not at all. The body can thus process fat ingested with food and, therefore, bitter substances are considered to be “fat burners”.
The gall bladder, in particular, needs bitter substances to be able to work properly. When they are absent, the gall bladder becomes lazier, no longer contracts properly, and stone formation can occur.

Curbing the appetite
It is believed that bitter substances still trigger the early human alarm that curbs the appetite, resulting in less being eaten. Satiety also lasts almost twice as long as with sweet substances. One slab of whole milk chocolate can be eaten a lot faster than one with a high cocoa content. Bitter foods contain far fewer calories. Earlier, many bitter substances in our diets caused food fat to be burned, rather than stored.

Prevention of tumours
Bitter substances have anti-oxidative effects and can prevent the formation of malignant tumours. In the United States, scientists at Yale University studied the taste preferences of 250 older men. The result: the lower the preference for bitter substances, the higher the presence of intestinal polyps (possible precursors of cancer).


There are, however, some bitter substances that, because of their ability to cross the blood brain barrier, have pharmacological effects e.g. theobromine and caffeine. Theobromine is structurally related to caffeine and belongs to the plant alkaloids. It is known for its vasodilatory (widening of blood vessels) and cough-suppressing effects. During industrial processing (roasting), the compound is released. It is found in the beans of the cacao tree or in the nuts of the kola tree. Chocolate contains up to 10% theobromine; the darker the chocolate, the higher the content.

A well-known medically used bitter substance, quinine is an alkaloid, which occurs naturally in the bark of the cinchona tree, and is used as a drug as well as a bittering agent. The effects of quinine are used against fevers, muscle cramps and malaria. Quinine’s side effects are collectively referred to as cinchonism or quinism and occur relatively frequently in long-term or high-dose administration. Side effects include nausea, vomiting, diarrhoea, headaches, ringing in the ears (tinnitus), blurred vision etc. Most of the side effects are dose-dependent and disappear after discontinuation of quinine therapy.

Barley juice alias beer

In accordance with the purity laws of 1516, beer today still consists of four basic ingredients – water, hops, malt and yeast. Hops belong to the family of hemp plants and contain valuable bitter substances, known as isohumulones (iso-alpha acids), which give beer its characteristic taste.

Last but not least, more than 1000 years ago already, the healer and Benedictine nun, Hildegard von Bingen, recommended taking bitter herbal drops to stay “healthy and strong”.

If you would like to find out more about bitter substances, we recommend the following websites:

The Kornspitz team is always happy to hear from you. If you have any questions, requests, suggestions or tips, please send an email to

Mag. Gerda Reimann-Dorninger
Nutrition Scientist

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