People have used citrus fruits as a source of medicines for thousands of years, but not in the citrus-flavored foods familiar to us today, like orange juice, key lime pie or lemon slices on slabs of salmon. While we usually consume the flesh and nectar of these succulent fruits as food, herbalists have used the rinds as medicine for numerous maladies throughout history.
In some cases, these discoveries in the apothecary led to innovation in the kitchen. For example, in Asia, the use of orange zest, lemon zest and dried orange peel in cooking developed out of the knowledge of their application as remedies for digestive disorders. A little citrus peel in your diet can go a long way.
Zesty Citrus Recipes
Ancient Healing: Traditional Uses of Peel
Traditional Chinese herbal medicine uses several citrus peels for specific health support, including those of mandarin orange (Citrus reticulata ‘Blanco’) and bitter orange (C. aurantium).
For hundreds of years, herbalists trained in Traditional Chinese Medicine (TCM) have used mature mandarin orange peel, known as chen pi or ju pi in Chinese medicine, to improve digestion, relieve intestinal gas and bloating, and resolve phlegm. This peel acts primarily on the digestive and respiratory systems. We apply it in conditions involving a sense of distension and fullness in the chest and upper middle abdomen combined with loss of appetite, vomiting or diarrhea, or coughs with copious phlegm.
Immature mandarin orange peel, known as qing pi in Chinese medicine, acts primarily on the liver and stomach to promote digestion, relieve food retention and abdominal distension, and promote good liver function. Practitioners of Chinese herbology use this herb when the sense of distension and discomfort lies primarily under the rib cage rather than the central abdomen.
The Chinese materia medica states that the rind of the mature bitter orange (zhi ke) relieves abdominal distension and chest congestion.
The rind of the immature bitter orange (zhi shi) relieves gas, bloating and constipation. It also dissolves phlegm. Practitioners of TCM consider it more purgative than the mature form.
Citrus Rind in Your Daily Diet
You don’t have to follow TCM to reap the benefits of citrus peel. Although we have discussed the traditions and uses in Chinese medicine, common sweet orange (C. sinensis) peel has many of the same constituents as the mandarin orange peel and also is beneficial to your health. You can incorporate 1 to 2 teaspoons of dried or powdered peel or 4 to 8 teaspoons of fresh peel into your daily diet, or you can try the yummy, easy recipes listed at the start of this article. Although cooking with healing herbs does not regulate your intake of the substance the way a regimented dose does, if you are looking to add some flavor and healing action to your meals, this is the way to do it!
Science Supports Citrus
Sweet and bitter orange peels have similar constituents. Modern research shows many benefits to these peels or their constituent phytochemicals.
The medicinal actions of citrus peels come in part from their primary essential oil, d-limonene. D-limonene has antimicrobial and anti-inflammatory properties. It also acts as a solvent for cholesterol, which has led some physicians to use it to dissolve cholesterol-containing gallstones. D-limonene neutralizes gastric acid and supports normal peristalsis, making it useful for relief of heartburn and gastroesophageal reflux disease (GERD). Research also indicates that d-limonene has cancer-preventive properties.
Citrus peels also contain hesperidin, a flavonoid that reduces the proliferation of cancer cells and induces programmed cell death in human colon cancer cells. Korean researchers found that qing pi extract induces programmed cell death in human colon cancer cells.
A team of scientists from Taiwan investigated the effects of the four citrus herbs mentioned above on adipocyte (fat cell) differentiation. They found that mandarin orange peel (chen pi) markedly reduced production and accumulation of triglycerides (fats) in fat cells, with the highest dose tested reducing triglyceride production by nearly 50 percent.
A team from the College of Pharmaceutical Sciences at Nankai University in Taijin, China, found that chen pi has anti-asthmatic properties.
Healing with Citrus Essential Oils
Orange oil acts as a sedative, relieving nervous tension and insomnia. Blend it with lavender, or alternate with lavender or sandalwood. It also enlivens the mind and relieves depression.
Use it externally to treat intestinal spasms, constipation and diarrhea. Mix 3 drops of orange oil into 1 tablespoon of sweet almond oil, then massage the oil into the abdomen. Start the massage in the lower right-hand quarter of the abdomen, then massage in a clockwise circle from that corner, up along the rib cage, across the upper abdomen, then down along the left side and into the pelvic area.
Other uses for orange oil: Add to massage oil to help normalize blood pressure and circulation. Combine with warming oils such as cinnamon and clove to fight chills and body aches.
Hold the Citrus Seed Extract
Buyer beware! Although several companies market grapefruit seed extract (GSE) as a “natural” antibiotic, research has revealed that citrus seed contains no antibiotic activity and the antibiotic actions of commercial GSE preparations appear to be due to the presence of synthetic preservatives.
Master herbalist Todd Caldecott has reported that two independent studies have shown that GSE does not have antibiotic actions of its own. According to Caldecott, in 1999 Japanese researchers compared a self-made alcohol extract of grapefruit seed to a commercial GSE and found that the latter contained methyl-p-hydroxybenzoate and triclosan, two synthetic, antibiotic preservatives.
Caldecott also cites a 1999 study by German researchers that compared the antimicrobial activity of self-made extract from the seed and juiceless pulp of grapefruit to six commercial GSEs. They concluded that GSE has no antimicrobial action of its own.
Caldecott further notes that neither triclosan nor benzethonium chloride (another preservative found in the commercial extracts) has FDA approval for internal use, and neither Chinese nor Ayurvedic medicine has traditionally used citrus seed to treat acute infectious disease.
Don Matesz, L.Ac., is a nutritionist, board-certified herbalist and acupuncturist. He lives and practices in Arizona.