Discover the benefits of black radish for the liver, gallbladder, and respiratory tract, with simple preparations (radish syrup, tincture), and the precautions to know.
Today I wanted to talk to you about the benefits of black radish. You probably know it as a vegetable; it’s actually quite yummy, crusty, and definitely a little spicy. But did you know it is also a major medicinal plant? At least in the French herbal tradition.
I’m going to explain in detail what it is used for and how to use it. You’ll see that when it is fresh, it can be made into very simple and useful preparations, especially during winter.
Before we start, I’d like to remind you that I am neither a doctor, pharmacist, nor healthcare professional. The information shared in this episode is for educational purposes only and is not intended to replace medical care.
Let’s start with a bit of botany. Black radish is Raphanus sativus var. niger. Raphanus sativus is the generic name for the cultivated radish (sativus means “cultivated”), and the variety niger is the black radish.
It belongs to the Brassicaceae family, the family of cabbage, mustard, and so on. So we can already expect the presence of sulfur compounds, which are characteristic of this family and bring beneficial properties, particularly for the liver and the lungs. We’ll come back to that in a few minutes.
By the way, the word “radish” comes from the Latin radix, meaning root. The root is, of course the part of the plant we use, both as food and as a medicine: it is very thick and fleshy. You may have noticed that, unlike the pink radish, the black radish has a very thick and rough skin. Many people peel it. Do not do that, keep the skin and eat it, and I’ll explain why in a few minutes. Assuming it’s organically grown, of course.
The plant is biennial. In its first year it only produces leaves, and in its second year it produces flowers and seeds, which marks the end of its cycle. The root is usually harvested in the fall of the first year. I harvest mine around October or November, when the root is at its largest. And if you don’t grow it in your garden, you can, of course, find black radish at your favorite organic grocery store.
Nutritionally, black radish is quite interesting. We don’t necessarily eat large amounts because it is quite strong and spicy. But we can slice it thinly into salads, or grate it. It can also be cooked, diced, and added to vegetable stews. Eating it raw is definitely better, but cooking it from time to time can add some variety.
Black radish contains a lot of water, a small amount of carbohydrates (which is normal, since carbs are a form of energy for plants, and the root is a storage organ). It contains fibers and is an excellent source of potassium, with about 300 mg per 100 g of fresh black radish.
It provides a fairly notable amount of vitamin C, around 10 mg per 100 g (1). This is why black radish was historically considered “anti scurvy”. Scurvy was a disease caused by a severe vitamin C deficiency. At a time when oranges and kiwis were not easy to come by, people made do with what they had.
It also contains some calcium, magnesium, as well as sulfur compounds that we call glucosinolates. They have a beneficial effect on the liver and the lungs, which we’ll discuss shortly.
That very dark skin owes its color to compounds called anthocyanins. These are powerful antioxidants. So when you slice or grate your organic black radish, keep the skin. And if a little soil remains on it, even better: it brings some beneficial bacteria from the ground, which are good for the microbiota.
OK, now let’s talk about properties and indications. The energetics, by the way, are heating and drying.
The first one is quite interesting. Black radish supports the process of liver detoxification.
To understand this, imagine the liver as a large recycling plant for waste and substances the body no longer needs. It breaks these substances down, keeps the parts that can be reused, and eliminates excess or toxic substances.
Elimination happens through two phases, simply called phase 1 and phase 2 detoxification. Sometimes the product of phase 1 is even more toxic than the starting substance. That is normal and part of the process, but it requires phase 2 to act immediately after phase 1 to neutralize that substance and send it toward the exit, either through bile and the intestinal tract, or through urine and the kidneys.
The problem is that sometimes the amount to process is so large that phase 2 is overwhelmed. Or the liver may lack the right cofactors to carry out this phase 2 transformation. There are natural substances, sulfur-based, that favor better liver detoxification, particularly phase 2. These substances are called glucosinolates, and black radish contains an abundance of them (2).
This was confirmed in tests done on poor animals who had to ingest toxic and carcinogenic products. They were divided into two groups: one group ate black radish, the other did not. Then the researchers measured the levels of these toxic products in the blood. The animals who ate black radish had significantly lower blood levels, and they suffer much less toxicity (3). All the references are on my site, as usual.
Some researchers even think that the anticancer properties of this family, the Brassicaceae family, are probably due precisely to the fact that phase 2 detoxification happens more efficiently and that these intermediate metabolites from phase 1 do not “stagnate” so to speak. So today, in the world we live in, we should eat black radish, and more generally, vegetables of the Brassicaceae family, on a regular basis.
This is why black radish is often recommended after prolonged or repeated exposure to toxins such as tobacco, carcinogenic substances, pesticides, and so on.
This is also why, in French herbalism, you will sometimes find black radish as a supportive plant for chronic skin problems, joint pain, migraines, and similar conditions. In tradition, these conditions have always been seen as conditions of accumulation of irritating substances in the bloodstream, in the joints, and so on. So one axis of the strategy is to help the body eliminate.
But let’s return to the liver and the gallbladder. Black radish is well known for its choleretic and cholagogue properties. This means that when you take black radish, the liver produces more bile, and the gallbladder contracts better to expel the bile that has been thickened between meals.
What is this useful for? Well, first of all, it can help when bile stagnates and could lead to thickened bile, biliary sludge, small stones, and so on. And here, be careful: check with your doctor, because when there are stones of a certain size, shaking the gallbladder too much with this type of plant can literally cause an obstruction, and then it’s straight to the emergency room.
Another important point is related to lipid digestion. Bile has multiple functions. One of which is to emulsify dietary fats. Bile breaks large fat droplets into microdroplets so that pancreatic enzymes can act on them. When a person has trouble digesting anything fatty, it can mean that this whole biliary axis is a bit too sluggish.
This can show up as trouble digesting as soon as a meal is a little too rich, with gas, bloating, a feeling of stagnation, a digestion that never seems to end, and so on. When this happens chronically, we can stimulate this whole biliary axis with plants like black radish.
Here is another role of bile: it is one of the most important digestive fluids. It moistens the stool and is mildly stimulating to the digestive mucosa, so it promotes better peristalsis, the wave-like movement that pushes the contents of the digestive tract toward the exit. So, when someone has chronic constipation and we suspect it could be due to a sluggish liver-biliary axis, we can use liver plants like black radish.
One last point related to bile: it is made of bile salts, which are formed from cholesterol derivatives. So the more bile we eliminate, the more cholesterol we eliminate. These choleretic plants are therefore typically used in cases of high cholesterol, which is another indication you’ll find in many reference books.
OK, enough about the liver. Now let’s give the floor to the respiratory system.
Black radish offers two very interesting properties. First, it is mucolytic, meaning it helps the lungs secrete more fluid mucus. Second, it is expectorant, meaning it helps better clear the accumulation of mucus.
This is why, in the French tradition, it is indicated for lung infections, bronchitis, and the like. If there is a productive, “wet” cough, black radish can thin the mucus and help bring it up and out. A very good preparation to have here is the famous black radish syrup, which is very easy to make.
So let’s talk about preparations and dosages.
First, there is the famous black radish syrup. Very simple and very quick to make.
For dosages, Dr. Valnet, one of our great herbal doctors of the past, recommended 4 to 6 tablespoons per day, and he says the syrup will overcome the most stubborn coughs.
He also says it is one of the best tonics you can give a tired teenager. Perhaps through a detoxification process ?
It can also be used as juice from a juicer, but be careful: it is sometimes poorly tolerated and can cause stomach upset. It is quite strong. So it depends on your tolerance, and it’s best to start very gently. Dr. Valnet recommends 20 to 50 g of juice per day. But again, go easy and test smaller quantities first.
It can be made into a tincture. Dr. Lorrain (another French herbal doc) recommends 20 to 30 drops in a little water, 2 to 3 times a day, and the dose can be increased depending on the situation.
You will also find dry extracts in capsules, which are a bit easier to take. The amount to take depends on the lab and the product.
The last form, which I’ve saved for the end: you can make an tea or decoction from black radish that has been thinly sliced and dried beforehand. But frankly, the taste is not great. And since some constituents of black radish are volatile, they are lost during the drying process. So it’s not my favorite form. That said, you would use around one teaspoon of the cut and dried roots per cup, 2 to 3 cups per day, if you feel like it. Not yummy.
In terms of precautions:
And that’s all for the benefits of black radish. It has something for everyone: it is both food and remedy, it is very easy to grow in the garden, and you can buy it from our small local producers.
It is very interesting for the whole respiratory sphere. And above all, it activates our recycling and detoxification center. What more could you ask for today?
Thanks for being here, I will see you very soon for the next episode of TheFrenchHerbal!
(1) Nutritional information here : https://ciqual.anses.fr/#/aliments/20089/radis-noir-cru
(2) Hanlon PR, Webber DM, Barnes DM. Aqueous extract from Spanish black radish (Raphanus sativus L. Var. niger) induces detoxification enzymes in the HepG2 human hepatoma cell line. J Agric Food Chem. 2007 Aug 8;55(16):6439-46. doi: 10.1021/jf070530f. Epub 2007 Jul 6. PMID: 17616135.
(3) N’jai AU, Kemp MQ, Metzger BT, Hanlon PR, Robbins M, Czuyprynski C, Barnes DM. Spanish black radish (Raphanus sativus L. Var. niger) diet enhances clearance of DMBA and diminishes toxic effects on bone marrow progenitor cells. Nutr Cancer. 2012;64(7):1038-48. doi: 10.1080/01635581.2012.714831. PMID: 23061907.
