Citrus fruits are the fruits of the trees belonging to the genus Citrus L., in the subfamily Aurantioideae Eaton of the family Rutaceae Juss.
Well known all over the world as fruits characterized by a typical soursweet (more or less sweet or sour according to species and variety) and sometimes bitter taste, they are mostly used as food, either raw or processed in several food preparations and recipes (e.g., marmalade), or possibly as flavoring ingredients (i.e., the dried or candied peels).
Unlike from what happens in Chinese Medicine, citrus fruits are almost unused in Western herbal practice, and this is really a pity considering the interesting properties they are endowed with. In fact, this is strictly true only for the contemporary western herbal practice: in the medical treatises of the sixtieth and seventieth centuries, indeed, citrus fruits are described similarly to the other medicinal herbs known at the time.
For instance, the Italian author Castore Durante wrote, in his Herbario Nuovo [Durante], about two of these fruits:
QUALITIES. The peel is warm & dry in the third degree, the pulp cools, & moistens in the first degree: the juice is cold in the third degree. The seed is warm & dry in the third degree.
VIRTUES. Internally. […] Their pulp is hard to digest, & generates a thick phlegm, reason why they are comfortably eaten with honey. The peel helps the digestion, confers to the melancholy: eaten in moderation comforts the stomach, but in great quantity injures it. Seasoned with honey warms the stomach, purges it from bad humors, & helps the digestion of foods. The seed is a remedy against all poisons, maximally against the bites of the scorpions when drunk: it induces the menses, & the abortion. The sour part mitigates the choler, & quenches the thirst when raw, or candied, and is useful against the plague contagion. […] The peel, seasoned with sugar, or honey corroborates the stomach, & the heart. With the sour part of the citron a conserve or a syrup may be prepared, that are very useful in the pestilential fevers.
QUALITIES. The peel is warm and dry in the beginning of the third degree: the pulp and the juicy part are cold, & dry in the second degree, & the sweet ones are not deprived of some warmth. The seed is warm & dry in the second degree.
VIRTUES. Internally. It has almost the same qualities of citron, the peel seasoned with sugar corroborates the stomach, expels the wind, & the phlegm, that are in the stomach. […] The juice of the sour ones is cold, but it is very appropriate in the fevers, & all the putrefactions, because they quench the thirst, & resist the putrefaction, & the sweet ones make harm with them.”
Still, in “Il tesoro della Sanità” [Durante2]:
Qualities. The peel is warm, & dry in the beginning of the third degree; the pulp, that is the juicy part, cold, & dry in the second degree; the seed is warm, & dry in the second degree. The sweet ones are moderately warm, & are pectoral; some other that are sour, are cold in the first degree; others that have an intermediate taste, are cold, & dry in a temperate manner.
Benefits. The sweet oranges, eaten before meals, are convenient to the stomach at any time, & are pectoral, are good for the melancholics, & the phlegmatic, & remove the oppilations; the sour ones quench the thirst, & awaken the appetite, their juice sprinkled on the roasted meats, or the fried fishes gives them grace, & suavity, & together with sugar they are eaten before meals, like the sweet ones: others have an intermediate taste, & these ones are pleasant to taste, awakens the appetite, are excellent in the choleric fevers, & sooth the throat, & quench the thirst: their peels can be reduced in a powder, that kills the worms, & taken with wine preserves from plague.
Harms. The sour oranges astringe the bowels strongly, & make the body styptic, & make the stomach cold, & constrict the chest, & the arteries, the sweet ones increase the choler during the fevers.
Remedies. The harms produced by the sour ones can be repaired, adding sugar, that is very stomachic, & eating those ones in small quantities. The sweet ones are good at any time for the elders, & the sour ones for the young during warm times, & for the cholerics, & sanguines, especially during the pestilential fevers.”
Castore Durante differentiates among sweet, sour and intermediate-taste oranges: since we find no description of any bitter taste, he refers probably to the common oranges, that is the furit of the Citrus sinensis (L.) Osbeck.
In the Traditional Chinese Medicine (TCM), the citrus fruits are classified as “herbs to mobilize and regulate the Qi”, that is, as drugs suited to treat some of the conditions known as “Qi stagnations” or “countercurrent Qi” (or “rebel Qi”). Such expressions, hard to understand for whoever knows not the Traditional Chinese Medicine thoroughly, define some “symptomatological pictures” (or syndromes) characterized by distension, either abdominal or thoracic, cough, dyspnea, vomiting, but also depression and/or gynecological disorders (like amenorrhea or dysmenorrhea).
The most similar western word, from a semantical point of view, is carminative, even though, with respect to the carminatives properly so called (that is, remedies that are specifically used to treat abdominal bloating and stimulate the digestive processes), such drugs have clearly more complex properties, according to Chinese medicine.
In TCM a distinction is made between the different types of citrus fruit, the used parts (the fruits, leaves, seeds, the fruit “piths” found at the center of the fruits, the peel with or without the albedo, or the “white spongy part” of the fruit) and the ripening stage (in case of fruits or peels). The most used fruits are:
- tangerine (mostly Citrus reticulata Blanco and its horticultural varieties): in this case, the peel of the ripe fruit with or without the albedo, the unripe fruit peel, the leaves, the seeds, and the fruit pith are used;
- bitter orange (Citrus x aurantium): the ripe or unripe fruit is used;
- citron (Citrus medica), both the common one and the form known as Buddha’s hand (Citrus medica var. sarcodactylus (Siebold ex Hoola van Nooten) Swingle): fruit and flowers are used.
Each fruit type and part has its own peculiar actions and action “nuances”.
All these drugs have a pungent and bitter or slightly bitter taste and a warm nature (only bitter orange is considered, by some authors, slightly cold).
Pungent (or acrid) is a sensation rather than a real taste and it is defined as a burning or numbing sensation on the tongue. It’s often caused by essential oils and so people often mistake pungent drugs for aromatic ones. But, indeed, the overlap between the two is only partial (not all pungent drugs are aromatic and not all aromatic drugs are pungent), since:
- the pungent taste may be caused by substances different from essential oils (like, for instance, protoanemonin in Ranunculaceae, capsaicin in hot pepper, thiocyanates in Allium and Brassicaceae, N-alkylamides in some Asteraceae like Echinacea and Acmella, etc.);
- the aromatic taste can be due to substances different from essential oils (e.g., coumarin or vanillin);
- not all essential oil bearing plants are (classified as) pungent, because they contain too little essential oil and/or because of the nature of the specific molecules contained in the essential oil: it is the case, for instance, of roses, classified in TCM, according to the species, as bitter and astringent (Flos Rosae Multiflorae), sweet (Flos Rosae Chinensis) or sweet and bitter (Flos Rosae Rugosae), but not pungent.
According to the TCM, the pungent taste is associated with the Lungs, which are responsible, among other things, to control the Wei Qi (Defensive Qi), the superficial circulation of Qi and fluids and, consequently, also the opening of the skin pores. Pungent drugs, indeed, are often able to modulate sweating (diaphoretic, antidiaphoretic or ambivalent drugs, like Sage, that increases sweating when drunk warm, and reduces sweating when drunk cold), and some of them alleviates cough and/or wheezing (Aster root, Tussilago flower, Perilla and Lepidium seeds) restoring the downward flowing of the Lung Qi.
Moreover, the pungent taste has also associated the specific action of activating the Qi circulation and dispersing moistness accumulation. Some pungent herbs are used specifically with these purposes (this is the case, for instance, with citrus fruits).
From a western point of view, essential oils are able to: cross the cellular membranes, quickly penetrating into the tissues; modulate dilatation and contractility of both deep and superficial blood vessels, so “altering” someway the superficial circulation and promoting or inhibiting sweating; act on bronchial contractility; thin and mobilize mucus; counteract infections, thanks to their antiseptic action. All these properties account, at least partially, for the numerous activities traditionally linked to the pungent herbs rich in essential oils.
Another important action of essential oils is the ability of acting upon the nervous system, modulating its activity in different ways, according to the vegetal species they are extracted from. Often the pungent and aromatic drugs are able to act upon the stress response, the mood and the “nervous” reactivity in general.
Back to the citrus topic, in TCM these drugs are generally deemed able to:
- regulate the Qi;
- adjust the Middle Jiao (Middle Burner: the acrid taste lifts the Spleen Qi and the bitter taste descends the Stomach Qi);
- dry dampness;
- resolve Phlegm;
- help the Spleen transport activity;
- direct Qi downward.
The entered meridians depend on the specific fruit, the used part and the ripening stage (in case of whole fruit or peel). Generally speaking, the entered meridians are those of Lungs and Stomach and those of Spleen or, alternatively, Liver. If the Spleen meridian is entered, the drug is most suitable when there are bloating and digestive deficiencies, possibly with vomiting; if the Liver meridian is entered, the drug is most suitable with thoracic or hypochondriac distension, possibly accompanied with anguish, depression, amenorrhea or dysmenorrhea. The drugs entering the Liver meridian can be used, generally speaking, to treat some cases of depression, in agreement with the symptomatologic picture and the action of the specific drug.
According to Michael Tierra [Tierra], almost all, if not all, the citrus peels and parts have carminative and Qi regulating actions:
- the ripe tangerine peel treats indigestion and intestinal spasms, promotes the expulsion of mucus from lungs and tonifies the Spleen; its quality is so much higher as it is more aged;
- the unripe tangerine peel action is stronger than the ripe tangerine, being able to treat biliary congestion, chest distension, painfulness caused by hernias, food stagnation, mucus or lymph congestion, fever and intermittent chills, breast cancer and abscesses;
- the tangerine pips treat mucus excess and Shan disorders (a generic expression used to describe scrotum and testicles diseases and inguinal hernias), like swollen and painful testicles;
- the tangerine pith has a carminative and antiemetic action, being useful in case of abdominal bloating, vomiting and hiccups;
- the bitter orange peel is cooler than that of tangerine and it’s indicated for treating aching and swelling of the abdominal and epigastric zones, food stagnation, indigestion with intestinal gas and constipation; it’s one of the strongest Qi mobilizing agents, so that it is used to “break” the masses (even the neoplastic ones);
- the orange peel has a cooler energy than tangerine, acting more softly;
- the lemon peel mobilizes the Liver and Spleen Qi;
- the lime peel is specifically indicated for Liver;
- the grapefruit peel is more suitable for Spleen.
Usually 3-10 grams of drug are used in decoction, expect for tangerine pith (6-10 gr). 30 grams of bitter orange dried fruit can be used as a large dosage.
[Durante] Castore Durante, “Herbario Nuovo”, Venezia, 1666
[Durante2] Castore Durante, “Il Tesoro della Sanità”, Turin, 1612
[Tierra] Michael Tierra, “Planetary Herbology”, Lotus Press (1992)