Radish is good for your health. At least, that’s what the old texts say. By old texts, I mean sources from the seventeenth to the nineteenth century. These are sometimes difficult to understand because they use a traditional medicinal concept to explain the benefits of radish. For a rough overview of this concept, please go to Radish (daikon) as medicine – the basics (part I).
And what do they say about the healthy aspects of radish?
Many of them more or less contain the same information in a more or less elaborate way, and I’m reluctant to post them all because this would become very boring and also somehow redundant. Instead, I would like to pick out some examples, which I consider as representative or which reveal some interesting insights into that time. It’s a subjective choice.
One of the earlier texts about radish (and food in general) as a ‘medicinal’ is a seventeenth century book called Gikin honzōshū yōka (“Key poems on beneficial and forbitten medicinal herbs”). Unfortunately, the author is not known, and the exact date of publication is uncertain too. I’ve chosen this text because it gives a clear summary of the different uses of the vegetable.
“Radish is sweet and warming. The vegetable is also pungent, relieves from overeating and eliminates proneness to dizziness. Radish is good for people who suffer from a blocked chest, and is used in the case of ‘stagnant vital energy’ (kijitsu). To be avoided when suffering from diarrhea. Radish warms the ‘inside’ (uchi) and digests food.
To be avoided when having spontaneous perspiration since it stimulates urination. Radish is medicine for both meat and poor-quality vegetable. It is beneficial for coughs, when vomiting blood or having a blocked nose. Radish very well appeases diabetes, emaciation, and the heat in spleen and kidneys that is caused by deficiency of yin humor (kyonetsu).
Radish is used for the body to discharge accumulation of phlegm and quench thirst. If you take in well-ground radish seeds, they will cure wind-phlegm [futan], vomiting and asthma. If you grind radish seeds well and add some broth (shiru) and put this into the nostrils, it will stop headache diseases.
Radish and eel should not be used with Rehmannia root. It will drive out phlegm and wears out spleen and kidneys. Radish juice moistens the lungs and has a strong ‘descending’ effect. It is a medicine against stagnation of nutriment when eating a grain-based diet.
Radish can be taken as a liquid medicine, and is especially a medicine for spleen and stomach erasing all kinds of illnesses. If radish is grilled, it will become pungent. Don’t take grilled radish as food, it fits with spleen and stomach but blocks the chest. It should be taken as medicine for all kinds of illnesses. It further becomes a medicine when being simmered. Radish juice is sweet, pungent, and warming. It is good when one has caught a cold and suffers from a blocked nose and headache.” (book 3, pp. 2a-3a)
For the explanation of the technical terms, see also Radish (daikon) as medicine – the basics (part I)
About two hundred years later….
The next source is an early nineteenth century food manual, the Nichiyō shokukagami (“Daily nurturing food mirror”, 1819), that focuses on ingredients used on a daily basis. The book can be regarded as a general introduction to food. The author is the herbalist and physician Ishikawa Genkon (dates unknown, probably). He kept the entries short. Maybe because he hoped that the people use the manual as a practical guide for everyday use, and long entries have a somehow discouraging effect. Anyway, in the foreword, he articulated the wish that the people have the manual “always at one’s side, [so] one can independently learn the knowledge about the benefit and harm of beverage and food without having the trouble to send for a physician.”
Now, let’s see what kind of information he presents:
“The root is pungent and sweet, the leaves are pungent and bitter, and both are warming and non-poisonous. Although the root causes the energy (ki) to move up if eaten fresh, it is very good in removing phlegm and expelling the intake of too much alcohol.
Further, if one uses radish juice when one is about to die because of fume poisoning [choking], it will be instantly effective. If consumed after being cooked, it causes the energy to descend, and is very good in digesting food, removing phlegm or any poison in flour products, fish, alcohol and tofu. If one becomes sick by radish, one should use fresh ginger.” (Nichiyō shokukagami, p. 27a)
Now we know: radish is good when having a hangover.
The benefit of radish against ‘choking’ appears in quite some food dictionaries of the seventeenth century up to the nineteenth. I guess this has to do with the frequently occurring blazes in the big cities during that time. The wooden houses were a welcoming bait for fire.
To briefly summarize the information in these sources:
Radish is good for all kinds of ailments that deal with the respiratory system and digestion.
This makes sense but how reliable are these sources?
These texts were written by Japanese authors who mostly had a botanical or medical background. Most of these authors made extensively use of imported herbal medical books from the continent, mainly China. Very influential texts, for example, were the Bencao gangmu (“Compendium of materia medica”, 1607) written by Li Shizhen (1518-1593) and Sun Simiao’s (?-682) Beiji Qianjin Yaofang (“Essential formulas for emergencies [worth] a thousand pieces of gold”), abbreviated as Qianjinfang.
However, it sometimes happened that the information in the Chinese sources differed from each other.
An example:
The Neo-Confucianist philosopher Kaibara Ekiken (1630-1714) wrote in a work on Japan’s botany, the Yamato honzō (“Materia Medica of Japan”, 1709) about radish the following:
“The Yaoxing jie says that raw radish descends the ki and if consumed [too] much of it, it wastes blood because it contains more pungency than sweetness, whereas cooked radish nourishes the spleen but if consumed a lot, it blocks the ki because it is more sweet than pungent.” (Yamato honzō, book 5, p. 1b)
The Chinese text he referred to is called Leigong paozhi yaoxing jie (“Explanation on Master Lei‘s [book] on properties of drugs and their processing”, 1662), and I checked whether Kaibara Ekiken did translate it properly. He did.
Did you see the difference to the other statements about the property of radish?
In all the other texts we have learned that when consumed raw, radish causes the energy (ki) to ascend, and when eaten cooked, it causes the energy (ki) to descend. How do you solve these conflicting statements? You could do it as the physicians of the past did. Trying it out. That means eating raw radish and observing what happens. For me, the statement that raw radish causes the energy (ki) to ascend (which my body expresses in the form of belches) makes perfect sense. Maybe Kaibara Ekiken didn’t like radish or he had a different digestion system…..
A no-go or not: Radish and Rehmannia root
Most physicians of the past were also aware that certain substances should not be administered at the same time because they could negatively influence the medical effect.
Here and there I came across the statement in the sources that the people mustn’t take Rehmannia root when consuming radish. Rehmannia root or Rehmannia glutinosa (jiō in Japanese, and dihuang in Chinese), also known as Chinese foxglove, is a frequently used medicinal herb/root in Traditional Chinese and Japanese medicines, and a firm component in many prescriptions.
Most of the authors of the Japanese food dictionaries however did not give any explanations why you should not consume them together, it seems that they just copied the relevant passages from Chinese sources without questioning its content. Luckily, I found an exception: It is the physician Hitomi Hitsudai who wrote the following in the Honchō shokkan:
“[In the Qianjinfang] Sun Simiao said that ‘radish should not be consumed together with Rehmannia glutinosa (jiō) because this leads to gray hair and causes the blood flow inside and outside the vessels to stagnate’. [In the Bencao gangmu] Li Shizen says that the direction [of the medical action of the two substances] are not the same and argues that the downwards going energy gets stuck.
That being said, it is not important to rehash [their reasoning]. Referring to the transmitted words of these authors, Rehmannia root is of cold character and slow in circulation whereas radish is warm and fast in circulation. [Therefore,] Radish cannot guide [the qi of the] Rehmannia root, and Rehmannia cannot follow radish.
What is then the reason for the stagnation of the same blood flow in and outside the vessels? Supposedly the ki of radish would go up and down ferociously and pass the ki of the Rehmannia root, and since it would not stay in the stomach and therefore cannot affect the efficacy of the Rehmannia root [because it is already gone], then we have to fairly say that this does not fit into the logic that it would cause the graying of the hair.” (Honchō shokkan, book 3, pp. 12a-b)
What did he mean?
I had a hard time to follow his reasoning. Apart from the complicated description of what happens, or in this case, what does not happen inside the body when consuming radish and Rehmannia root at the more or less same time, it is interesting to see how the author tried to recap the interaction of vegetable and drug in a time of limited technological means.
Okay, to sum up the physicians assumed that you can get gray hair and blood problems.
And what’s the point of this?
Unlike the statement in the Bencao gangmu, Hitsudai noticed that the people who took Rehmannia root and radish at the same time and on a regular basis did not get gray hair. His remarks also reveal that the intake of Rehmannia was a common thing. Here comes the relevant passage:
“These days, there are people who always take the six or eight-ingredients-Rehmannia pills, or people who take them one or two days, or one month, or even longer than a year, that these people cannot eat radish is just foolish. Supposing one took a pure Rehmannia pill separately from a grain-based meal, then radish and Rehmannia would not interfere, the grain-based meal would enter the stomach becoming part of the movement [in the stomach], and then turn and leave. Why should then the Rehmannia medicine stay [in the stomach] and wait for the radish to come?” (Honchō shokkan, book 3, p. 12b)
I have no idea whether radish and Rehmannia root can actually harm the body when taken simultaneously.
But why did they all take this medicine?
The answer is simple: these Rehmannia pills were used as an aphrodisiac!
They seemed to have been quite popular in the seventeenth century, since these ‘pills’ are even mentioned in a famous amorous work written by the well-known poet Ihara Saikaku (1642-1693). They usually consisted of several ingredients of which Rehmannia root was the main one. Hitsudai even mentioned some of the other ingredients:
“In the six-ingredient [pill], there is Poria cocos (bukuryō), threeleaf arrowhead (Sagittaria trifolia, omodaka), and sake, which are all good guides and movers for Rehmannia, and the eight-ingredient-[pill] has also added the rigorous speed of processed aconit […]. Then this little bit of radish should not be a problem. People always gossip that forty-to-fifty-year-olds who take Rehmannia pills regularly do not have dark hair, [get senile] speckles and turn gray, and that this is due to the lack of a ban on radish. How absurd is this!? When only relying on the vitality of the six-ingredient pill, the constantly belligerent genital blood and uterus bleeding do not only turn the hair entirely gray but finally lead to death. Why do they blame the radish root for that?” (Honchō shokkan, book 3, p. 12b)
It looks like the people constantly misused the Rehmannia pill.
By the way, the six-ingredient pill is still sold today in Japanese Kanpō pharmacies. Not as an aphrodisiac. It is prescribed for weakness and numbness in the lower limps, urination problems, and physical weariness.
Radish leaves
To return to radish and its benefits, it is not only the root that is healthy but also the leaves. This actually does not only apply to radish, the leaves of many other root vegetables are edible too, such as beet root or carrot leaves. An exception are the leaves of potatoes that belong to the night shade family, they are toxic!
The leaves were less a topic in sources on materia medica but mentioned here and there in texts on food. The aforementioned Hitsudai for example wrote:
“ […] the root is pungent and sweet; the leaves are pungent and bitter. Warm. Non-toxic. Ginger very well controls the harms (doku) of the radish. If the radish leaves are sun-dried, they become sweet and warm and are good for one’s health.[…] In my opinion, the dried leaves and stems drive out moisture (shitsu) very well, harmonize the blood and work well as diuretic. It is also good to blanch the cleaned leaves and stems. […]” (Honchō shokkan, book 3, pp. 10b-12a)
Speaking of radish leaves, they also were (and still are) a popular tsukemono (pickle).
And today? Are we still aware of the beneficial effects of radish?
For the answer, see